/* Book Reading — modern theme */
:root {
  --bk-ink: #0f1419;
  --bk-paper: #f7f4ef;
  --bk-card-bg: #ffffff;
  --bk-brand: #2c5282;
  --bk-brand-deep: #1a365d;
  --bk-gold: #c9a227;
  --bk-gold-soft: #f5ecd8;
  --bk-muted: #6b6560;
  --bk-line: rgba(15, 20, 25, 0.08);
  --bk-font-display: "Source Han Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --bk-primary: var(--bk-brand);
  --bk-primary-hover: #1e4a7a;
  --bk-accent: var(--bk-gold);
  --bk-accent-soft: var(--bk-gold-soft);
  --bk-bg: var(--bk-paper);
  --bk-surface: var(--bk-card-bg);
  --bk-read-bg: #faf8f5;
  --bk-text: var(--bk-ink);
  --bk-text-muted: var(--bk-muted);
  --bk-border: var(--bk-line);
  --bk-radius: 12px;
  --bk-radius-sm: 8px;
  --bk-radius-lg: 16px;
  --bk-shadow: 0 4px 24px rgba(15, 20, 25, 0.06);
  --bk-shadow-lg: 0 12px 40px rgba(15, 20, 25, 0.1);
  --bk-font: "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  --bk-serif: var(--bk-font-display);
  --bk-header-h: 72px;
  --bk-container: 1200px;
  --bk-read-width: 720px;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body.bk-body {
  margin: 0;
  font-family: var(--bk-font);
  font-size: 15px;
  line-height: 1.6;
  color: var(--bk-text);
  background: var(--bk-bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--bk-primary); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--bk-accent); }

img { max-width: 100%; height: auto; vertical-align: middle; }

.bk-container {
  width: 100%;
  max-width: var(--bk-container);
  margin: 0 auto;
  padding: 0 20px;
}

/* ========== Header ========== */
.bk-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: box-shadow 0.3s, background 0.3s;
}

.bk-header__bar {
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px) saturate(1.2);
  border-bottom: 1px solid var(--bk-border);
}

.bk-header.is-scrolled .bk-header__bar {
  box-shadow: 0 8px 32px rgba(28, 25, 23, 0.08);
}

.bk-header__row {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 16px 20px;
  min-height: var(--bk-header-h);
}

/* Logo */
.bk-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  text-decoration: none;
  line-height: 0;
}

.bk-logo img {
  height: 42px;
  width: auto;
  max-width: 160px;
  object-fit: contain;
}

/* Nav — 一级 + 二级下拉 */
.bk-nav {
  display: flex;
  align-items: center;
  flex: 0 1 auto;
  gap: 2px;
  min-width: 0;
  justify-content: flex-end;
  margin-left: auto;
  padding: 0;
}

.bk-nav__home,
.bk-nav__solo {
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: var(--bk-text-muted);
  white-space: nowrap;
  border-radius: 8px;
  transition: color 0.2s, background 0.2s;
}

.bk-nav__home:hover,
.bk-nav__solo:hover {
  color: var(--bk-primary);
  background: rgba(30, 77, 140, 0.06);
}

.bk-nav__home.is-active,
.bk-nav__solo.is-active {
  color: var(--bk-primary);
  background: rgba(30, 77, 140, 0.1);
}

.bk-nav__item {
  position: relative;
}

.bk-nav__trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: var(--bk-text-muted);
  white-space: nowrap;
  border-radius: 8px;
  transition: color 0.2s, background 0.2s;
}

.bk-nav__trigger i {
  font-size: 12px;
  opacity: 0.65;
  transition: transform 0.25s;
}

.bk-nav__item:hover .bk-nav__trigger,
.bk-nav__item.is-active .bk-nav__trigger {
  color: var(--bk-primary);
  background: rgba(30, 77, 140, 0.06);
}

.bk-nav__item:hover .bk-nav__trigger i {
  transform: rotate(180deg);
}

.bk-nav__item.is-active .bk-nav__trigger {
  background: rgba(30, 77, 140, 0.1);
}

.bk-nav__panel {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  padding-top: 10px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.22s, transform 0.22s, visibility 0.22s;
  z-index: 1100;
}

.bk-nav__item:hover .bk-nav__panel {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

.bk-nav__panel-inner {
  min-width: 320px;
  max-width: 420px;
  background: var(--bk-surface);
  border: 1px solid var(--bk-border);
  border-radius: 14px;
  box-shadow: 0 20px 50px rgba(28, 25, 23, 0.14);
  overflow: hidden;
}

.bk-nav__panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 18px;
  background: linear-gradient(135deg, rgba(30, 77, 140, 0.08), rgba(224, 122, 58, 0.05));
  border-bottom: 1px solid var(--bk-border);
  color: var(--bk-text);
  font-size: 14px;
}

.bk-nav__panel-head:hover {
  color: var(--bk-primary);
}

.bk-nav__panel-head strong {
  font-weight: 600;
}

.bk-nav__panel-head span {
  font-size: 12px;
  color: var(--bk-text-muted);
}

.bk-nav__children {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
  padding: 10px;
  max-height: 320px;
  overflow-y: auto;
}

.bk-nav__child {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 10px;
  color: var(--bk-text);
  font-size: 13px;
  transition: background 0.15s;
}

.bk-nav__child:hover {
  background: var(--bk-bg);
  color: var(--bk-primary);
}

.bk-nav__child.is-active {
  background: rgba(30, 77, 140, 0.1);
  color: var(--bk-primary);
  font-weight: 600;
}

.bk-nav__child-thumb {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  overflow: hidden;
  background: var(--bk-bg);
}

.bk-nav__child-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bk-nav__child-name {
  line-height: 1.35;
}

/* Tools */
.bk-header__tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.bk-search {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bk-bg);
  border: 1px solid var(--bk-border);
  border-radius: 10px;
  padding: 0 6px 0 14px;
  width: 240px;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.bk-search:focus-within {
  border-color: var(--bk-primary);
  box-shadow: 0 0 0 3px rgba(30, 77, 140, 0.12);
}

.bk-search__icon {
  color: var(--bk-text-muted);
  font-size: 14px;
  flex-shrink: 0;
}

.bk-search input {
  flex: 1;
  border: none;
  background: transparent;
  outline: none;
  font-size: 14px;
  min-width: 0;
  height: 40px;
}

.bk-search__btn {
  border: none;
  background: var(--bk-primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  padding: 0 14px;
  height: 32px;
  border-radius: 8px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}

.bk-search__btn:hover {
  background: var(--bk-primary-hover);
}

.bk-header__icon-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  color: var(--bk-text-muted);
  font-size: 16px;
  transition: background 0.2s, color 0.2s;
}

.bk-header__icon-btn:hover {
  background: var(--bk-bg);
  color: var(--bk-primary);
}

.bk-header__icon-label {
  font-size: 10px;
  font-weight: 500;
}

/* User */
.bk-user__guest {
  display: flex;
  align-items: center;
  gap: 8px;
}

.bk-user__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  height: 38px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 10px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s, background 0.2s;
  white-space: nowrap;
}

.bk-user__btn:hover {
  transform: translateY(-1px);
}

.bk-user__btn--ghost {
  background: transparent;
  color: var(--bk-text);
  border: 1px solid var(--bk-border);
}

.bk-user__btn--ghost:hover {
  border-color: var(--bk-primary);
  color: var(--bk-primary);
}

.bk-user__btn--primary {
  background: linear-gradient(135deg, var(--bk-primary), #2d6cb5);
  color: #fff;
  box-shadow: 0 4px 12px rgba(30, 77, 140, 0.3);
}

.bk-user__btn--primary:hover {
  color: #fff;
}

.bk-user__btn--block {
  width: 100%;
  margin-bottom: 8px;
}

.bk-user__logged {
  position: relative;
}

.bk-user__trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 10px 4px 4px;
  border: 1px solid var(--bk-border);
  border-radius: 999px;
  background: var(--bk-surface);
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.bk-user__trigger:hover,
.bk-user__trigger[aria-expanded="true"] {
  border-color: var(--bk-primary);
  box-shadow: 0 4px 16px rgba(30, 77, 140, 0.12);
}

.bk-user__avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
}

.bk-user__name {
  font-size: 13px;
  font-weight: 600;
  color: var(--bk-text);
  max-width: 80px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.bk-user__caret {
  font-size: 14px;
  color: var(--bk-text-muted);
  transition: transform 0.2s;
}

.bk-user__trigger[aria-expanded="true"] .bk-user__caret {
  transform: rotate(180deg);
}

.bk-user__dropdown {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  width: 260px;
  background: var(--bk-surface);
  border-radius: 14px;
  border: 1px solid var(--bk-border);
  box-shadow: 0 16px 48px rgba(28, 25, 23, 0.14);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity 0.2s, transform 0.2s, visibility 0.2s;
  z-index: 1100;
  overflow: hidden;
}

.bk-user__dropdown.is-open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.bk-user__card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: linear-gradient(135deg, rgba(30, 77, 140, 0.08), rgba(224, 122, 58, 0.06));
  border-bottom: 1px solid var(--bk-border);
}

.bk-user__card img {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.bk-user__card strong {
  display: block;
  font-size: 15px;
  color: var(--bk-text);
}

.bk-user__card span {
  font-size: 12px;
  color: var(--bk-text-muted);
}

.bk-user__menu {
  display: flex;
  flex-direction: column;
  padding: 8px;
}

.bk-user__menu a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  font-size: 14px;
  color: var(--bk-text);
  border-radius: 8px;
  transition: background 0.15s;
}

.bk-user__menu a i {
  width: 18px;
  text-align: center;
  color: var(--bk-text-muted);
}

.bk-user__menu a:hover {
  background: var(--bk-bg);
  color: var(--bk-primary);
}

.bk-user__menu a.is-danger {
  color: #dc2626;
}

.bk-user__menu a.is-danger:hover {
  background: #fef2f2;
  color: #b91c1c;
}

/* Burger & drawer */
.bk-header__burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 1px solid var(--bk-border);
  border-radius: 10px;
  background: var(--bk-surface);
  cursor: pointer;
}

.bk-header__burger span {
  display: block;
  height: 2px;
  background: var(--bk-text);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}

.bk-header__drawer {
  position: fixed;
  inset: 0;
  z-index: 2000;
  pointer-events: none;
}

.bk-header__drawer.is-open {
  pointer-events: auto;
}

.bk-header__drawer-mask {
  position: absolute;
  inset: 0;
  background: rgba(15, 20, 25, 0.45);
  opacity: 0;
  transition: opacity 0.3s;
}

.bk-header__drawer.is-open .bk-header__drawer-mask {
  opacity: 1;
}

.bk-header__drawer-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: min(320px, 88vw);
  height: 100%;
  background: var(--bk-surface);
  box-shadow: -8px 0 40px rgba(0,0,0,0.15);
  transform: translateX(100%);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.bk-header__drawer.is-open .bk-header__drawer-panel {
  transform: translateX(0);
}

.bk-header__drawer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  border-bottom: 1px solid var(--bk-border);
}

.bk-drawer-logo img {
  height: 36px;
  width: auto;
  max-width: 140px;
  object-fit: contain;
}

.bk-header__drawer-head button {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 8px;
  background: var(--bk-bg);
  cursor: pointer;
  font-size: 18px;
  color: var(--bk-text-muted);
}

.bk-header__drawer-search {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 12px 16px;
  padding: 0 6px 0 12px;
  background: var(--bk-bg);
  border: 1px solid var(--bk-border);
  border-radius: 10px;
}

.bk-header__drawer-search i {
  color: var(--bk-text-muted);
  font-size: 14px;
}

.bk-header__drawer-search input {
  flex: 1;
  border: none;
  background: transparent;
  outline: none;
  height: 42px;
  font-size: 14px;
  min-width: 0;
}

.bk-header__drawer-search button {
  border: none;
  background: var(--bk-primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  padding: 0 14px;
  height: 34px;
  border-radius: 8px;
  cursor: pointer;
}

.bk-header__drawer-nav {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px 16px;
}

.bk-drawer-home,
.bk-drawer-solo {
  display: block;
  padding: 14px 16px;
  font-size: 15px;
  font-weight: 600;
  color: var(--bk-text);
  border-radius: 10px;
}

.bk-drawer-home:hover,
.bk-drawer-solo:hover,
.bk-drawer-solo.is-active {
  background: var(--bk-bg);
  color: var(--bk-primary);
}

.bk-drawer-group {
  border-bottom: 1px solid var(--bk-border);
}

.bk-drawer-group__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 14px 16px;
  border: none;
  background: transparent;
  font-size: 15px;
  font-weight: 600;
  color: var(--bk-text);
  cursor: pointer;
  text-align: left;
}

.bk-drawer-group__toggle i {
  transition: transform 0.25s;
  color: var(--bk-text-muted);
}

.bk-drawer-group.is-open .bk-drawer-group__toggle i {
  transform: rotate(180deg);
}

.bk-drawer-group__body {
  display: none;
  padding: 0 8px 12px 16px;
}

.bk-drawer-group.is-open .bk-drawer-group__body {
  display: block;
}

.bk-drawer-group__body a {
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  color: var(--bk-text-muted);
  border-radius: 8px;
  border-left: 2px solid transparent;
}

.bk-drawer-group__body a:hover,
.bk-drawer-group__body a.is-active {
  color: var(--bk-primary);
  background: rgba(30, 77, 140, 0.06);
  border-left-color: var(--bk-accent);
}

.bk-drawer-group__all {
  font-weight: 600;
  color: var(--bk-text) !important;
  margin-bottom: 4px;
}

.bk-header__drawer-member {
  margin-top: auto;
  padding: 20px;
  border-top: 1px solid var(--bk-border);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.bk-header__drawer-member > a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--bk-text);
  border-radius: 10px;
}

.bk-header__drawer-member > a:hover {
  background: var(--bk-bg);
}

.bk-header__drawer-member > a.is-danger {
  color: #dc2626;
}

.bk-user__card--drawer {
  margin-bottom: 12px;
  border-radius: 12px;
  border: none;
}

body.bk-drawer-open {
  overflow: hidden;
}

@media (max-width: 1200px) {
  .bk-nav__trigger,
  .bk-nav__home,
  .bk-nav__solo {
    padding: 8px 10px;
    font-size: 13px;
  }

  .bk-search {
    width: 200px;
  }
}

@media (max-width: 1024px) {
  .bk-nav {
    display: none;
    margin-left: 0;
  }

  .bk-header__tools {
    margin-left: auto;
  }

  .bk-header__burger {
    display: flex;
  }

  .bk-search {
    width: 180px;
  }

  .bk-search__btn {
    padding: 0 10px;
    font-size: 0;
    width: 32px;
    overflow: hidden;
  }

  .bk-search__btn::before {
    content: "\f002";
    font-family: FontAwesome;
    font-size: 13px;
  }

  .bk-user__name {
    display: none;
  }

  .bk-header__icon-label {
    display: none;
  }
}

@media (max-width: 640px) {
  .bk-search {
    display: none;
  }

  .bk-header__icon-btn {
    display: none;
  }

  .bk-user__btn--ghost {
    display: none;
  }

  .bk-logo__tag {
    display: none;
  }

  .bk-header__row {
    gap: 12px;
  }
}

/* Main layout */
.bk-main { padding: 28px 0 48px; min-height: calc(100vh - var(--bk-header-h) - 120px); }

/* Breadcrumb */
.bk-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--bk-text-muted);
  margin-bottom: 24px;
}

.bk-breadcrumb a { color: var(--bk-text-muted); }
.bk-breadcrumb a:hover { color: var(--bk-primary); }
.bk-breadcrumb__sep { opacity: 0.4; }

/* Buttons */
.bk-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.2s;
}

.bk-btn:hover { transform: translateY(-1px); }

.bk-btn--primary {
  background: linear-gradient(135deg, var(--bk-brand), var(--bk-brand-deep));
  color: #fff;
  box-shadow: 0 4px 14px rgba(44, 82, 130, 0.35);
}

.bk-btn--primary:hover { color: #fff; box-shadow: 0 6px 20px rgba(44, 82, 130, 0.45); }

.bk-btn--accent {
  background: var(--bk-gold);
  color: #fff;
  box-shadow: 0 4px 14px rgba(201, 162, 39, 0.35);
}

.bk-btn--accent:hover { color: #fff; }

.bk-btn--outline {
  background: transparent;
  border: 1.5px solid var(--bk-border);
  color: var(--bk-text);
}

.bk-btn--outline:hover {
  border-color: var(--bk-primary);
  color: var(--bk-primary);
}

.bk-btn--sm { padding: 6px 14px; font-size: 13px; }

/* Hero */
.bk-hero {
  position: relative;
  border-radius: var(--bk-radius);
  overflow: hidden;
  margin-bottom: 40px;
  min-height: 320px;
  background: linear-gradient(135deg, #1e4d8c 0%, #2d6cb5 50%, #4a8fd4 100%);
}

.bk-hero__slide {
  display: none;
  padding: 48px 40px;
  color: #fff;
  min-height: 320px;
  align-items: center;
}

.bk-hero__slide.is-active { display: flex; }

.bk-hero__content { max-width: 480px; }

.bk-hero__tag {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(255,255,255,0.2);
  border-radius: 999px;
  font-size: 12px;
  margin-bottom: 12px;
}

.bk-hero h2 {
  margin: 0 0 12px;
  font-size: 32px;
  font-weight: 700;
  line-height: 1.25;
}

.bk-hero p { margin: 0 0 20px; opacity: 0.9; font-size: 15px; }

.bk-hero__dots {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
}

.bk-hero__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,0.4);
  border: none;
  cursor: pointer;
  padding: 0;
}

.bk-hero__dot.is-active { background: #fff; width: 24px; border-radius: 4px; }

/* Section */
.bk-section { margin-bottom: 48px; }

.bk-section__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.bk-section__title {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
}

.bk-section__more {
  font-size: 14px;
  color: var(--bk-text-muted);
}

.bk-section__more:hover { color: var(--bk-primary); }

.bk-subcats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.bk-subcats a {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: 999px;
  background: var(--bk-surface);
  border: 1px solid var(--bk-border);
  color: var(--bk-text-muted);
}

.bk-subcats a:hover {
  border-color: var(--bk-primary);
  color: var(--bk-primary);
}

/* Book card grid */
.bk-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 20px;
}

.bk-card {
  background: var(--bk-surface);
  border-radius: var(--bk-radius);
  overflow: hidden;
  box-shadow: var(--bk-shadow);
  transition: transform 0.25s, box-shadow 0.25s;
}

.bk-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--bk-shadow-lg);
}

.bk-card__cover {
  position: relative;
  aspect-ratio: 2/3;
  overflow: hidden;
  background: #e7e5e4;
}

.bk-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bk-card__badge {
  position: absolute;
  top: 8px;
  left: 8px;
  padding: 3px 8px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 4px;
  background: var(--bk-accent);
  color: #fff;
}

.bk-card__badge--done { background: #16a34a; }

.bk-card__body { padding: 12px 14px 16px; }

.bk-card__title {
  margin: 0 0 6px;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.bk-card__title a { color: inherit; }
.bk-card__title a:hover { color: var(--bk-primary); }

.bk-card__desc {
  font-size: 12px;
  color: var(--bk-text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin: 0;
}

/* List row (search/list) */
.bk-list { display: flex; flex-direction: column; gap: 16px; }

.bk-list-item {
  display: flex;
  gap: 20px;
  padding: 20px;
  background: var(--bk-surface);
  border-radius: var(--bk-radius);
  box-shadow: var(--bk-shadow);
  transition: box-shadow 0.2s;
}

.bk-list-item:hover { box-shadow: var(--bk-shadow-lg); }

.bk-list-item__cover {
  flex-shrink: 0;
  width: 100px;
  border-radius: var(--bk-radius-sm);
  overflow: hidden;
  aspect-ratio: 2/3;
  background: #e7e5e4;
}

.bk-list-item__cover img { width: 100%; height: 100%; object-fit: cover; }

.bk-list-item__main { flex: 1; min-width: 0; }

.bk-list-item__title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
}

.bk-list-item__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
  color: var(--bk-text-muted);
  margin-bottom: 8px;
}

.bk-list-item__desc {
  margin: 0;
  font-size: 14px;
  color: var(--bk-text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Book detail */
.bk-detail {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 32px;
  background: var(--bk-surface);
  border-radius: var(--bk-radius);
  padding: 32px;
  box-shadow: var(--bk-shadow);
  margin-bottom: 24px;
}

.bk-detail__cover {
  border-radius: var(--bk-radius-sm);
  overflow: hidden;
  box-shadow: var(--bk-shadow-lg);
  aspect-ratio: 2/3;
}

.bk-detail__cover img { width: 100%; height: 100%; object-fit: cover; }

.bk-detail__title {
  margin: 0 0 8px;
  font-size: 28px;
  font-weight: 700;
  line-height: 1.3;
}

.bk-detail__author {
  font-size: 15px;
  color: var(--bk-text-muted);
  margin-bottom: 16px;
}

.bk-detail__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--bk-text-muted);
  margin-bottom: 20px;
}

.bk-detail__meta span { display: flex; align-items: center; gap: 6px; }

.bk-detail__desc {
  font-size: 15px;
  line-height: 1.8;
  color: var(--bk-text-muted);
  margin-bottom: 24px;
}

.bk-detail__actions { display: flex; flex-wrap: wrap; gap: 12px; }

/* Panel */
.bk-panel {
  background: var(--bk-surface);
  border-radius: var(--bk-radius-lg);
  border: 1px solid var(--bk-line);
  box-shadow: var(--bk-shadow);
  margin-bottom: 24px;
  overflow: hidden;
}

.bk-panel__head {
  padding: 16px 24px;
  border-bottom: 1px solid var(--bk-line);
  font-family: var(--bk-font-display);
  font-size: 17px;
  font-weight: 600;
  display: flex;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
}

.bk-panel__head .bk-home-label {
  margin-bottom: 0;
}

.bk-panel__body--muted {
  font-size: 13px;
  color: var(--bk-text-muted);
  line-height: 1.8;
}

.bk-panel__body { padding: 20px 24px; }

/* Chapter accordion */
.bk-chapters { border: none; }

.bk-chapter-vol {
  border-bottom: 1px solid var(--bk-border);
}

.bk-chapter-vol:last-child { border-bottom: none; }

.bk-chapter-vol__toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 14px 24px;
  border: none;
  background: var(--bk-bg);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
  color: var(--bk-text);
}

.bk-chapter-vol__toggle:hover { background: #ede9e4; }

.bk-chapter-vol__toggle i { transition: transform 0.2s; }
.bk-chapter-vol.is-open .bk-chapter-vol__toggle i { transform: rotate(180deg); }

.bk-chapter-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: none;
}

.bk-chapter-vol.is-open .bk-chapter-list { display: block; }

.bk-chapter-list li {
  border-top: 1px solid var(--bk-border);
}

.bk-chapter-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px 12px 36px;
  color: var(--bk-text);
  font-size: 14px;
}

.bk-chapter-list a:hover { background: var(--bk-accent-soft); color: var(--bk-accent); }

.bk-tag {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.bk-tag--vip { background: #fef3c7; color: #b45309; }
.bk-tag--free { background: #dcfce7; color: #15803d; }

/* Sidebar */
.bk-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 24px;
  align-items: start;
}

.bk-side-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.bk-side-list li { border-bottom: 1px solid var(--bk-border); }
.bk-side-list li:last-child { border-bottom: none; }

.bk-side-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  color: var(--bk-text);
  font-size: 14px;
}

.bk-side-list a:hover { color: var(--bk-primary); }

.bk-side-list__num {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  background: var(--bk-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  color: var(--bk-text-muted);
  flex-shrink: 0;
}

.bk-side-list li:nth-child(-n+3) .bk-side-list__num {
  background: var(--bk-primary);
  color: #fff;
}

/* Search filters */
.bk-filters {
  background: var(--bk-surface);
  border-radius: var(--bk-radius);
  padding: 20px 24px;
  margin-bottom: 24px;
  box-shadow: var(--bk-shadow);
}

.bk-filter-row {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 10px 0;
  border-bottom: 1px solid var(--bk-border);
}

.bk-filter-row:last-child { border-bottom: none; }

.bk-filter-label {
  flex-shrink: 0;
  width: 72px;
  font-size: 13px;
  color: var(--bk-text-muted);
  padding-top: 6px;
}

.bk-filter-tags { display: flex; flex-wrap: wrap; gap: 8px; }

.bk-filter-tags a {
  padding: 6px 14px;
  font-size: 13px;
  border-radius: 999px;
  border: 1px solid var(--bk-border);
  color: var(--bk-text-muted);
}

.bk-filter-tags a.is-active,
.bk-filter-tags a:hover {
  background: var(--bk-primary);
  border-color: var(--bk-primary);
  color: #fff;
}

.bk-sort {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.bk-sort a {
  padding: 8px 16px;
  font-size: 13px;
  border-radius: var(--bk-radius-sm);
  background: var(--bk-surface);
  border: 1px solid var(--bk-border);
  color: var(--bk-text-muted);
}

.bk-sort a.is-active,
.bk-sort a:hover {
  background: rgba(30, 77, 140, 0.08);
  border-color: var(--bk-primary);
  color: var(--bk-primary);
}

/* Reading page */
body.bk-read-body {
  background: var(--bk-read-bg);
  min-height: 100vh;
}

body.bk-read-body .bk-main {
  display: none;
}

.bk-read-wrap {
  padding: 0 0 100px;
}

.bk-read-subheader {
  position: sticky;
  top: var(--bk-header-h);
  z-index: 90;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--bk-line);
  box-shadow: 0 4px 20px rgba(15, 20, 25, 0.04);
}

.bk-read-subheader__inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 16px;
  min-height: 64px;
  padding: 12px 0;
}

.bk-read-subheader__back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--bk-muted);
  white-space: nowrap;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--bk-line);
  background: var(--bk-card-bg);
  transition: color 0.2s, border-color 0.2s;
}

.bk-read-subheader__back:hover {
  color: var(--bk-brand);
  border-color: rgba(44, 82, 130, 0.25);
}

.bk-read-subheader__meta {
  min-width: 0;
  text-align: center;
}

.bk-read-subheader__book {
  display: block;
  font-size: 12px;
  color: var(--bk-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bk-read-subheader__book a {
  color: var(--bk-brand);
}

.bk-read-subheader__title {
  margin: 4px 0 0;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--bk-ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bk-read-subheader__catalog {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  color: var(--bk-brand);
  background: rgba(44, 82, 130, 0.08);
  border: 1px solid rgba(44, 82, 130, 0.15);
  border-radius: 999px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}

.bk-read-subheader__catalog:hover {
  background: rgba(44, 82, 130, 0.14);
}

.bk-read-sheet {
  max-width: var(--bk-read-width);
  margin: 24px auto 0;
  padding: 0 20px;
}

.bk-read-article {
  background: var(--bk-card-bg);
  border: 1px solid var(--bk-line);
  border-radius: var(--bk-radius-lg);
  box-shadow: var(--bk-shadow);
  padding: 40px 48px 48px;
}

.bk-read-content {
  font-family: var(--bk-serif);
  font-size: 19px;
  line-height: 2.05;
  letter-spacing: 0.02em;
  color: #2a2622;
  text-align: justify;
  word-break: break-word;
}

.bk-read-content p {
  margin: 0 0 1.35em;
  text-indent: 2em;
}

.bk-read-content p:first-child {
  text-indent: 0;
}

.bk-read-content img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.5em auto;
  border-radius: var(--bk-radius-sm);
}

.bk-read-chapter-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px dashed var(--bk-line);
}

.bk-read-chapter-nav a {
  flex: 1;
  max-width: 48%;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 18px;
  font-size: 14px;
  color: var(--bk-ink);
  background: var(--bk-paper);
  border: 1px solid var(--bk-line);
  border-radius: var(--bk-radius);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.bk-read-chapter-nav a:hover {
  border-color: rgba(44, 82, 130, 0.25);
  box-shadow: 0 4px 16px rgba(15, 20, 25, 0.06);
  color: var(--bk-brand);
}

.bk-read-chapter-nav a.is-next {
  text-align: right;
  margin-left: auto;
}

.bk-read-chapter-nav__label {
  font-size: 12px;
  color: var(--bk-muted);
}

.bk-read-chapter-nav__name {
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bk-read-vip {
  text-align: center;
  padding: 72px 32px;
  background: linear-gradient(180deg, #fff 0%, var(--bk-paper) 100%);
  border-radius: var(--bk-radius-lg);
  border: 1px solid var(--bk-line);
  box-shadow: var(--bk-shadow);
}

.bk-read-vip h3 {
  margin: 0 0 12px;
  font-size: 22px;
  color: var(--bk-ink);
}

.bk-read-vip h3 i {
  color: var(--bk-gold);
  margin-right: 8px;
}

.bk-read-vip p {
  color: var(--bk-text-muted);
  margin: 0 0 28px;
  font-size: 15px;
}

body.bk-read-body .bk-footer {
  margin-top: 32px;
}

/* Reading toolbar */
.bk-read-toolbar {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 6px 8px;
  background: var(--bk-card-bg);
  border: 1px solid var(--bk-line);
  border-radius: 999px;
  box-shadow: 0 8px 32px rgba(15, 20, 25, 0.12);
  z-index: 200;
}

.bk-read-toolbar__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  min-width: 56px;
  padding: 8px 10px;
  border: none;
  background: transparent;
  border-radius: 12px;
  cursor: pointer;
  color: var(--bk-muted);
  font-size: 11px;
  transition: background 0.2s, color 0.2s;
}

.bk-read-toolbar__item i {
  font-size: 18px;
}

.bk-read-toolbar__item:hover {
  background: var(--bk-paper);
  color: var(--bk-brand);
}

.bk-read-toolbar__item.is-shelf {
  color: var(--bk-gold);
}

.bk-read-toolbar__item:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* 阅读页章节目录侧栏 */
.bk-read-catalog {
  position: fixed;
  inset: 0;
  z-index: 1200;
  pointer-events: none;
  visibility: hidden;
}

.bk-read-catalog.is-open {
  pointer-events: auto;
  visibility: visible;
}

.bk-read-catalog__mask {
  position: absolute;
  inset: 0;
  background: rgba(15, 20, 25, 0.45);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.bk-read-catalog.is-open .bk-read-catalog__mask {
  opacity: 1;
}

.bk-read-catalog__aside {
  position: absolute;
  top: 0;
  right: 0;
  width: min(400px, 92vw);
  height: 100%;
  background: var(--bk-surface);
  display: flex;
  flex-direction: column;
  box-shadow: -8px 0 32px rgba(15, 20, 25, 0.15);
  transform: translateX(100%);
  transition: transform 0.3s ease;
}

.bk-read-catalog.is-open .bk-read-catalog__aside {
  transform: translateX(0);
}

.bk-read-catalog__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--bk-line);
  font-weight: 700;
  flex-shrink: 0;
}

.bk-read-catalog__close {
  border: none;
  background: var(--bk-bg);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  color: var(--bk-text-muted);
}

.bk-read-catalog__close:hover {
  color: var(--bk-brand);
}

.bk-read-catalog__body {
  flex: 1;
  overflow-y: auto;
  padding: 0;
  -webkit-overflow-scrolling: touch;
}

.bk-read-catalog__body .bk-chapter-list a.is-current {
  color: var(--bk-brand);
  font-weight: 600;
  background: var(--bk-gold-soft);
}

body.bk-read-catalog-open {
  overflow: hidden;
}

@media (max-width: 768px) {
  .bk-read-subheader__inner {
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
  }

  .bk-read-subheader__back {
    grid-column: 1;
    grid-row: 1;
  }

  .bk-read-subheader__catalog {
    grid-column: 2;
    grid-row: 1;
  }

  .bk-read-subheader__meta {
    grid-column: 1 / -1;
    grid-row: 2;
    text-align: left;
    padding-top: 4px;
  }

  .bk-read-article {
    padding: 28px 22px 36px;
  }

  .bk-read-content {
    font-size: 17px;
    line-height: 1.95;
  }

  .bk-read-chapter-nav {
    flex-direction: column;
  }

  .bk-read-chapter-nav a {
    max-width: 100%;
  }

  .bk-read-chapter-nav a.is-next {
    text-align: left;
  }

  .bk-read-toolbar__item span {
    display: none;
  }

  .bk-read-toolbar__item {
    min-width: 44px;
    padding: 10px;
  }
}

/* Category cover */
.bk-cat-hero {
  text-align: center;
  padding: 40px 24px;
  background: linear-gradient(180deg, var(--bk-surface) 0%, var(--bk-bg) 100%);
  border-radius: var(--bk-radius);
  margin-bottom: 32px;
}

.bk-cat-hero h1 { margin: 0 0 8px; font-size: 28px; }
.bk-cat-hero p { margin: 0; color: var(--bk-text-muted); }

/* Pagination */
.bk-pagination {
  display: flex;
  justify-content: center;
  margin-top: 32px;
}

.bk-pagination .pagination {
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
  list-style: none;
  padding: 0;
}

.bk-pagination .pagination > li > a,
.bk-pagination .pagination > li > span {
  display: block;
  padding: 8px 14px;
  border-radius: var(--bk-radius-sm);
  border: 1px solid var(--bk-border);
  color: var(--bk-text-muted);
  background: var(--bk-surface);
}

.bk-pagination .pagination > .active > a,
.bk-pagination .pagination > li > a:hover {
  background: var(--bk-primary);
  border-color: var(--bk-primary);
  color: #fff;
}

.bk-empty {
  text-align: center;
  padding: 60px 24px;
  color: var(--bk-text-muted);
}

.bk-empty i { font-size: 48px; opacity: 0.3; display: block; margin-bottom: 16px; }

/* Footer */
.bk-footer {
  background: #1c1917;
  color: #a8a29e;
  padding: 40px 0 24px;
  margin-top: auto;
}

.bk-footer__inner {
  text-align: center;
  font-size: 13px;
  line-height: 1.8;
}

.bk-footer a { color: #d6d3d1; }
.bk-footer a:hover { color: #fff; }

.bk-back-top {
  position: fixed;
  right: 24px;
  bottom: 90px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bk-surface);
  border: 1px solid var(--bk-border);
  box-shadow: var(--bk-shadow);
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 50;
  color: var(--bk-text-muted);
}

.bk-back-top.is-visible { display: flex; }

/* Buy page — 完整样式见文末「VIP 购买页」 */

/* Responsive */
@media (max-width: 992px) {
  .bk-layout { grid-template-columns: 1fr; }
  .bk-detail { grid-template-columns: 180px 1fr; gap: 24px; padding: 24px; }
}

@media (max-width: 768px) {
  .bk-header__inner { gap: 12px; }
  .bk-nav { display: none; }
  .bk-search { min-width: 0; flex: 1; }
  .bk-detail { grid-template-columns: 1fr; text-align: center; }
  .bk-detail__cover { max-width: 200px; margin: 0 auto; }
  .bk-detail__actions { justify-content: center; }
  .bk-hero h2 { font-size: 24px; }
  .bk-hero__slide { padding: 32px 24px; }
  .bk-list-item { flex-direction: column; }
  .bk-list-item__cover { width: 120px; }
  .bk-read-content { font-size: 17px; }
}


/* ========== 全站页面组件（源自首页样式） ========== */
.bk-page-home .bk-main {
  padding: 0;
  min-height: auto;
}

/* ========== Banner ========== */
.bk-home-hero {
  padding: 20px 0 8px;
  background: var(--bk-paper);
}

.bk-home-hero__shell {
  position: relative;
  border-radius: 24px;
  overflow: hidden;
  min-height: 440px;
  background: linear-gradient(135deg, #ffffff 0%, #f3f7fc 42%, #faf6ef 100%);
  border: 1px solid var(--bk-line);
  box-shadow:
    0 4px 6px rgba(15, 20, 25, 0.02),
    0 20px 50px rgba(44, 82, 130, 0.1);
}

.bk-home-hero__blobs {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.bk-home-hero__blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.5;
}

.bk-home-hero__blob--1 {
  width: 280px;
  height: 280px;
  background: #c5daf5;
  top: -80px;
  right: 10%;
}

.bk-home-hero__blob--2 {
  width: 200px;
  height: 200px;
  background: #f5e6c8;
  bottom: -40px;
  left: 5%;
}

.bk-home-hero__blob--3 {
  width: 160px;
  height: 160px;
  background: #d4e8f7;
  top: 40%;
  left: 45%;
}

.bk-home-hero__track {
  position: relative;
  min-height: 440px;
}

.bk-home-hero__slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.65s ease, visibility 0.65s;
  pointer-events: none;
}

.bk-home-hero__slide.is-active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.bk-home-hero__bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center right;
  opacity: 0.12;
  transform: scale(1.05);
}

.bk-home-hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1fr minmax(220px, 300px);
  gap: 40px;
  align-items: center;
  min-height: 440px;
  padding: 40px 48px 88px;
}

.bk-home-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  font-size: 12px;
  font-weight: 600;
  color: var(--bk-brand);
  background: rgba(44, 82, 130, 0.08);
  border: 1px solid rgba(44, 82, 130, 0.12);
  border-radius: 999px;
  margin-bottom: 18px;
}

.bk-home-hero__eyebrow i {
  color: var(--bk-gold);
}

.bk-home-hero__title {
  margin: 0 0 14px;
  font-family: var(--bk-font-display);
  font-size: clamp(26px, 3.5vw, 40px);
  font-weight: 600;
  line-height: 1.25;
  color: var(--bk-ink);
  letter-spacing: 0.02em;
}

.bk-home-hero__desc {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bk-muted);
  max-width: 520px;
}

.bk-home-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 13px;
  color: var(--bk-muted);
  margin-bottom: 26px;
}

.bk-home-hero__meta i {
  margin-right: 6px;
  color: var(--bk-brand);
}

.bk-home-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.bk-home-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s, border-color 0.2s;
  text-decoration: none;
}

.bk-home-btn:hover {
  transform: translateY(-2px);
}

.bk-home-btn--primary {
  background: linear-gradient(135deg, var(--bk-brand) 0%, #3d6db5 100%);
  color: #fff;
  box-shadow: 0 8px 24px rgba(44, 82, 130, 0.28);
}

.bk-home-btn--primary:hover {
  color: #fff;
  box-shadow: 0 12px 32px rgba(44, 82, 130, 0.35);
}

.bk-home-btn--outline {
  background: #fff;
  color: var(--bk-brand);
  border: 1.5px solid rgba(44, 82, 130, 0.25);
}

.bk-home-btn--outline:hover {
  border-color: var(--bk-brand);
  background: rgba(44, 82, 130, 0.04);
  color: var(--bk-brand);
}

.bk-home-btn--light {
  background: #fff;
  color: var(--bk-brand-deep);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.bk-home-btn--light:hover {
  color: var(--bk-brand-deep);
}

.bk-home-hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.bk-home-hero__cover {
  position: relative;
  width: 100%;
  max-width: 260px;
  border-radius: 12px;
  overflow: hidden;
  box-shadow:
    0 20px 50px rgba(44, 82, 130, 0.22),
    0 0 0 1px rgba(15, 20, 25, 0.06);
  transition: transform 0.5s ease, box-shadow 0.5s ease;
}

.bk-home-hero__slide.is-active .bk-home-hero__cover {
  transform: translateY(-4px);
  box-shadow:
    0 28px 60px rgba(44, 82, 130, 0.28),
    0 0 0 1px rgba(15, 20, 25, 0.06);
}

.bk-home-hero__cover img {
  display: block;
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
}

.bk-home-hero__footer {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px 24px;
}

.bk-home-hero__progress {
  display: flex;
  gap: 8px;
}

.bk-home-hero__dot {
  width: 32px;
  height: 4px;
  padding: 0;
  border: none;
  border-radius: 4px;
  background: rgba(44, 82, 130, 0.15);
  cursor: pointer;
  transition: width 0.3s, background 0.3s;
}

.bk-home-hero__dot.is-active {
  width: 48px;
  background: var(--bk-brand);
}

.bk-home-hero__arrows {
  display: flex;
  gap: 8px;
}

.bk-home-hero__arrow {
  width: 42px;
  height: 42px;
  border: 1px solid var(--bk-line);
  border-radius: 12px;
  background: #fff;
  color: var(--bk-brand);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
  box-shadow: 0 2px 8px rgba(15, 20, 25, 0.04);
}

.bk-home-hero__arrow:hover {
  background: var(--bk-brand);
  border-color: var(--bk-brand);
  color: #fff;
}

/* ========== 分类入口 ========== */
.bk-home-channel {
  margin-top: 32px;
  padding-bottom: 56px;
}

.bk-home-channel__head {
  text-align: center;
  margin-bottom: 28px;
}

.bk-home-channel__head h2 {
  margin: 0 0 6px;
  font-family: var(--bk-font-display);
  font-size: 26px;
  font-weight: 600;
}

.bk-home-channel__head p {
  margin: 0;
  color: var(--bk-muted);
  font-size: 15px;
}

.bk-home-channel__grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.bk-home-channel__card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 24px 16px;
  background: var(--bk-card-bg);
  border-radius: var(--bk-radius-lg);
  box-shadow: 0 4px 24px rgba(15, 20, 25, 0.06);
  border: 1px solid var(--bk-line);
  color: var(--bk-ink);
  text-align: center;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
  position: relative;
  overflow: hidden;
}

.bk-home-channel__card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 60%, rgba(201, 162, 39, 0.06));
  opacity: 0;
  transition: opacity 0.25s;
}

.bk-home-channel__card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(15, 20, 25, 0.1);
  border-color: rgba(201, 162, 39, 0.35);
  color: var(--bk-ink);
}

.bk-home-channel__card:hover::after {
  opacity: 1;
}

.bk-home-channel__thumb {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  overflow: hidden;
  background: var(--bk-gold-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: var(--bk-gold);
}

.bk-home-channel__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bk-home-channel__name {
  font-size: 15px;
  font-weight: 600;
}

.bk-home-channel__arrow {
  font-size: 12px;
  color: var(--bk-muted);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 0.2s, transform 0.2s;
}

.bk-home-channel__card:hover .bk-home-channel__arrow {
  opacity: 1;
  transform: translateX(0);
  color: var(--bk-gold);
}

/* ========== 人气榜 ========== */
.bk-home-rank {
  padding: 16px 0 56px;
}

.bk-home-label {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bk-gold);
  margin-bottom: 6px;
}

.bk-home-rank__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 24px;
}

.bk-home-rank__head h2 {
  margin: 0;
  font-family: var(--bk-font-display);
  font-size: 28px;
  font-weight: 600;
}

.bk-home-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--bk-muted);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.bk-home-link:hover {
  color: var(--bk-brand);
}

.bk-home-rank__scroll {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  padding: 8px 4px 20px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--bk-gold) transparent;
}

.bk-home-rank__scroll::-webkit-scrollbar {
  height: 6px;
}

.bk-home-rank__scroll::-webkit-scrollbar-thumb {
  background: var(--bk-gold);
  border-radius: 3px;
}

.bk-home-rank__item {
  flex: 0 0 280px;
  scroll-snap-align: start;
  display: grid;
  grid-template-columns: 36px 72px 1fr;
  gap: 14px;
  align-items: center;
  padding: 16px;
  background: var(--bk-card-bg);
  border-radius: var(--bk-radius-lg);
  border: 1px solid var(--bk-line);
  color: var(--bk-ink);
  transition: box-shadow 0.25s, transform 0.25s;
}

.bk-home-rank__item:hover {
  box-shadow: 0 12px 32px rgba(15, 20, 25, 0.08);
  transform: translateY(-2px);
  color: var(--bk-ink);
}

.bk-home-rank__num {
  font-family: var(--bk-font-display);
  font-size: 28px;
  font-weight: 600;
  color: var(--bk-line);
  line-height: 1;
}

.bk-home-rank__item:nth-child(1) .bk-home-rank__num { color: #d4a012; }
.bk-home-rank__item:nth-child(2) .bk-home-rank__num { color: #9ca3af; }
.bk-home-rank__item:nth-child(3) .bk-home-rank__num { color: #b87333; }

.bk-home-rank__cover {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.12);
}

.bk-home-rank__cover img {
  width: 72px;
  height: 108px;
  object-fit: cover;
  display: block;
}

.bk-home-rank__info {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.bk-home-rank__info strong {
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.bk-home-rank__info em {
  font-style: normal;
  font-size: 13px;
  color: var(--bk-muted);
}

.bk-home-rank__info small {
  font-size: 12px;
  color: var(--bk-muted);
}

/* ========== 分类区块 ========== */
.bk-home-block {
  padding: 48px 0;
  border-top: 1px solid var(--bk-line);
}

.bk-home-block:nth-child(even) {
  background: rgba(255, 255, 255, 0.5);
}

.bk-home-block__head {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 20px;
  align-items: end;
  margin-bottom: 20px;
}

.bk-home-block__index {
  font-family: var(--bk-font-display);
  font-size: 48px;
  font-weight: 600;
  line-height: 1;
  color: var(--bk-gold-soft);
  -webkit-text-stroke: 1px var(--bk-gold);
  color: transparent;
}

.bk-home-block__titles h2 {
  margin: 0 0 4px;
  font-family: var(--bk-font-display);
  font-size: 26px;
  font-weight: 600;
}

.bk-home-block__titles p {
  margin: 0;
  font-size: 14px;
  color: var(--bk-muted);
}

.bk-home-block__tabs-wrap {
  position: relative;
  margin-bottom: 24px;
}

.bk-home-block__tabs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.bk-home-block__tabs a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  padding: 8px 16px;
  min-height: 38px;
  font-size: 13px;
  font-weight: 500;
  line-height: 1.3;
  white-space: nowrap;
  border-radius: 999px;
  background: var(--bk-card-bg);
  border: 1px solid var(--bk-line);
  color: var(--bk-muted);
  transition: border-color 0.2s, color 0.2s, background 0.2s, box-shadow 0.2s;
  -webkit-tap-highlight-color: transparent;
}

.bk-home-block__tabs a:hover {
  border-color: var(--bk-brand);
  color: var(--bk-brand);
  background: rgba(44, 82, 130, 0.06);
}

.bk-home-block__tabs a:active {
  transform: scale(0.98);
}

.bk-home-block__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 24px;
}

/* 书籍卡片 */
.bk-home-card {
  background: var(--bk-card-bg);
  border-radius: var(--bk-radius-lg);
  overflow: hidden;
  border: 1px solid var(--bk-line);
  transition: transform 0.3s, box-shadow 0.3s;
}

.bk-home-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 48px rgba(15, 20, 25, 0.1);
}

.bk-home-card__cover {
  position: relative;
  display: block;
  aspect-ratio: 2/3;
  overflow: hidden;
  background: #e8e4df;
}

.bk-home-card__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.bk-home-card:hover .bk-home-card__cover img {
  transform: scale(1.06);
}

.bk-home-card__shine {
  position: absolute;
  inset: 0;
  background: linear-gradient(125deg, transparent 40%, rgba(255,255,255,0.25) 50%, transparent 60%);
  transform: translateX(-100%);
  transition: transform 0.6s;
}

.bk-home-card:hover .bk-home-card__shine {
  transform: translateX(100%);
}

.bk-home-card__status {
  position: absolute;
  top: 10px;
  left: 10px;
  padding: 4px 10px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 6px;
  background: rgba(15, 20, 25, 0.75);
  color: #fff;
  backdrop-filter: blur(4px);
}

.bk-home-card__status.is-end {
  background: rgba(22, 163, 74, 0.9);
}

.bk-home-card__body {
  padding: 16px 18px 18px;
}

.bk-home-card__body h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.bk-home-card__body h3 a {
  color: var(--bk-ink);
}

.bk-home-card__body h3 a:hover {
  color: var(--bk-brand);
}

.bk-home-card__author {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--bk-gold);
  font-weight: 500;
}

.bk-home-card__desc {
  margin: 0 0 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--bk-muted);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.bk-home-card__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--bk-muted);
  padding-top: 12px;
  border-top: 1px solid var(--bk-line);
}

.bk-home-card__read {
  font-size: 13px;
  font-weight: 600;
  color: var(--bk-brand);
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(44, 82, 130, 0.08);
}

.bk-home-card__read:hover {
  background: var(--bk-brand);
  color: #fff;
}

/* ========== CTA ========== */
.bk-home-cta {
  padding: 64px 0 80px;
}

.bk-home-cta__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 48px 56px;
  border-radius: 24px;
  background: linear-gradient(135deg, var(--bk-brand-deep) 0%, var(--bk-brand) 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
}

.bk-home-cta__inner::before {
  content: "";
  position: absolute;
  width: 320px;
  height: 320px;
  right: -80px;
  top: -80px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(201, 162, 39, 0.25) 0%, transparent 70%);
}

.bk-home-cta__text {
  position: relative;
  z-index: 1;
}

.bk-home-cta__text h2 {
  margin: 0 0 8px;
  font-family: var(--bk-font-display);
  font-size: 28px;
  font-weight: 600;
}

.bk-home-cta__text p {
  margin: 0;
  opacity: 0.85;
  font-size: 16px;
}

.bk-home-cta .bk-home-btn {
  position: relative;
  z-index: 1;
  flex-shrink: 0;
}

.bk-footer--home {
  margin-top: 0;
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .bk-home-channel__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .bk-home-hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 32px 28px 96px;
    min-height: auto;
  }

  .bk-home-hero__shell,
  .bk-home-hero__track {
    min-height: auto;
  }

  .bk-home-hero__desc {
    margin-left: auto;
    margin-right: auto;
  }

  .bk-home-hero__actions,
  .bk-home-hero__meta {
    justify-content: center;
  }

  .bk-home-hero__visual {
    order: -1;
  }

  .bk-home-hero__cover {
    max-width: 200px;
  }

  .bk-home-hero__footer {
    padding: 0 28px 20px;
  }
}

@media (max-width: 768px) {
  .bk-home-channel {
    margin-top: 24px;
  }

  .bk-home-channel__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .bk-home-block__head {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .bk-home-block__index {
    font-size: 36px;
  }

  .bk-home-rank__item {
    flex: 0 0 260px;
  }

  .bk-home-cta__inner {
    flex-direction: column;
    text-align: center;
    padding: 36px 28px;
  }

  .bk-home-hero {
    padding: 12px 0 4px;
  }

  .bk-home-hero__shell {
    border-radius: 16px;
  }

  .bk-home-hero__inner {
    padding: 24px 20px 88px;
    gap: 24px;
  }

  .bk-home-hero__footer {
    padding: 0 20px 16px;
  }

  .bk-page-hero {
    padding: 24px 20px;
  }

  .bk-home-block__grid--page {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
}

/* ========== 内页（与首页统一） ========== */
.bk-page-hero {
  padding: 32px 36px;
  margin-bottom: 28px;
  border-radius: var(--bk-radius-lg);
  background: linear-gradient(135deg, #ffffff 0%, #f3f7fc 42%, #faf6ef 100%);
  border: 1px solid var(--bk-line);
  box-shadow: var(--bk-shadow);
}

.bk-page-hero h1 {
  margin: 8px 0 10px;
  font-family: var(--bk-font-display);
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 600;
  color: var(--bk-ink);
}

.bk-page-hero p {
  margin: 0;
  color: var(--bk-muted);
  font-size: 15px;
}

.bk-page-hero--compact {
  padding: 24px 28px;
  margin-bottom: 20px;
}

.bk-page-hero--detail.bk-detail {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 32px;
  margin-bottom: 24px;
}

.bk-page-hero--detail .bk-detail__title {
  font-family: var(--bk-font-display);
}

.bk-home-block--inner {
  padding: 8px 0 48px;
  border-top: none;
  background: transparent;
}

.bk-home-block--inner:nth-child(even) {
  background: transparent;
}

.bk-home-block--inner .bk-home-block__titles h2 {
  margin: 0 0 4px;
}

.bk-home-block--inner .bk-home-block__titles h2 a {
  color: var(--bk-ink);
}

.bk-home-block--inner .bk-home-block__titles h2 a:hover {
  color: var(--bk-brand);
}

.bk-home-block__grid--page {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
  margin-bottom: 28px;
}

.bk-panel--filters {
  margin-bottom: 16px;
}

.bk-panel--filters .bk-filters {
  margin: 0;
}

.bk-sort {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.bk-sort a {
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--bk-muted);
  background: var(--bk-card-bg);
  border: 1px solid var(--bk-line);
  border-radius: 999px;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.bk-sort a:hover {
  color: var(--bk-brand);
  border-color: rgba(44, 82, 130, 0.25);
}

.bk-sort a.is-active {
  background: rgba(44, 82, 130, 0.08);
  color: var(--bk-brand);
  border-color: rgba(44, 82, 130, 0.2);
}

.bk-filter-tags a.is-active {
  background: rgba(44, 82, 130, 0.08);
  color: var(--bk-brand);
  border-color: rgba(44, 82, 130, 0.2);
}

/* ========== VIP 购买页 ========== */
.bk-buy-box.bk-page-hero {
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
  padding: 36px 40px 32px;
}

.bk-buy-box.bk-page-hero .bk-home-label {
  margin-bottom: 8px;
}

.bk-buy-box.bk-page-hero h1 {
  margin: 0 0 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--bk-line);
}

.bk-buy-row {
  display: flex;
  align-items: flex-start;
  gap: 20px 24px;
  padding: 20px 0;
  border-bottom: 1px solid var(--bk-line);
}

.bk-buy-row:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.bk-buy-row__label {
  flex: 0 0 72px;
  width: 72px;
  margin: 0;
  padding-top: 2px;
  font-size: 14px;
  font-weight: 600;
  color: var(--bk-muted);
  line-height: 1.5;
}

.bk-buy-row > span:not(.bk-buy-row__label) {
  flex: 1;
  min-width: 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--bk-ink);
  font-weight: 500;
}

/* 嵌入的支付表单（Pay 模块 buy.html） */
.bk-buy-box #payform.form-horizontal {
  margin: 0;
  width: 100%;
}

.bk-buy-box #payform .form-body {
  padding: 0;
  background: transparent;
  border: none;
  box-shadow: none;
}

.bk-buy-box #payform .form-group {
  display: block;
  margin: 0 0 22px;
  padding: 0;
}

.bk-buy-box #payform .form-group::before,
.bk-buy-box #payform .form-group::after {
  display: none;
}

.bk-buy-box #payform .control-label {
  float: none;
  display: block;
  width: 100%;
  max-width: none;
  padding: 0 0 8px;
  margin: 0;
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  color: var(--bk-muted);
  line-height: 1.4;
}

.bk-buy-box #payform .control-label[style] {
  padding-top: 0 !important;
}

.bk-buy-box #payform [class*="col-md-"] {
  float: none;
  width: 100%;
  max-width: 100%;
  padding: 0;
}

.bk-buy-box #payform .form-control-static {
  padding: 0;
  min-height: 0;
  line-height: 1.4;
}

.bk-buy-box #payform .fc-price-color {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  color: var(--bk-brand);
  letter-spacing: -0.02em;
}

.bk-buy-box #payform .fc-price-color .fa {
  margin-right: 4px;
  font-size: 0.9em;
  opacity: 0.85;
}

.bk-buy-box #payform .btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  width: 100%;
  vertical-align: top;
}

.bk-buy-box #payform .btn-group > label.btn {
  position: relative;
  float: none;
  flex: 1 1 calc(50% - 5px);
  min-width: 120px;
  margin: 0 !important;
  cursor: pointer;
  padding: 12px 16px !important;
  font-size: 14px !important;
  font-weight: 500;
  line-height: 1.35;
  text-align: center;
  white-space: nowrap;
  border-radius: var(--bk-radius-sm) !important;
  border: 1.5px solid var(--bk-line) !important;
  background: var(--bk-card-bg) !important;
  color: var(--bk-ink) !important;
  box-shadow: none !important;
  transition: border-color 0.2s, background 0.2s, color 0.2s;
}

.bk-buy-box #payform .btn-group > label.btn .fa {
  margin-right: 6px;
}

.bk-buy-box #payform .btn-group > label.btn:hover {
  border-color: rgba(44, 82, 130, 0.35) !important;
  color: var(--bk-brand) !important;
  background: #fff !important;
}

.bk-buy-box #payform .btn-group > label.btn.active,
.bk-buy-box #payform .btn-group > label.btn.active:focus {
  background: rgba(44, 82, 130, 0.08) !important;
  border-color: var(--bk-brand) !important;
  color: var(--bk-brand) !important;
  box-shadow: 0 0 0 1px rgba(44, 82, 130, 0.12) !important;
}

.bk-buy-box #payform .btn-group > label.btn input.toggle {
  position: absolute;
  clip: rect(0, 0, 0, 0);
  pointer-events: none;
}

.bk-buy-box #payform .form-actions.fc-form-actions {
  margin: 8px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--bk-line);
}

.bk-buy-box #payform .form-actions .control-label {
  display: none;
}

.bk-buy-box #payform .fc-form-submit {
  padding: 0;
}

.bk-buy-box #payform .btn.green {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 48px;
  padding: 14px 28px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.2;
  color: #fff !important;
  background: linear-gradient(135deg, var(--bk-brand), var(--bk-brand-deep)) !important;
  border: none !important;
  border-radius: var(--bk-radius) !important;
  box-shadow: 0 4px 16px rgba(44, 82, 130, 0.35);
  transition: transform 0.15s, box-shadow 0.2s, filter 0.2s;
}

.bk-buy-box #payform .btn.green:hover,
.bk-buy-box #payform .btn.green:focus {
  color: #fff !important;
  filter: brightness(1.05);
  box-shadow: 0 6px 22px rgba(44, 82, 130, 0.42);
  transform: translateY(-1px);
}

@media (max-width: 768px) {
  .bk-buy-box.bk-page-hero {
    padding: 28px 20px 24px;
  }

  .bk-buy-row {
    flex-direction: column;
    gap: 8px;
    padding: 16px 0;
  }

  .bk-buy-row__label {
    flex: none;
    width: auto;
    padding-top: 0;
  }

  .bk-buy-box #payform .btn-group > label.btn {
    flex: 1 1 100%;
    min-width: 0;
  }

  .bk-buy-box #payform .fc-price-color {
    font-size: 20px;
  }

  .bk-page-hero--detail.bk-detail {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 24px;
  }

  .bk-page-hero--detail .bk-detail__cover {
    max-width: 200px;
    margin: 0 auto;
  }

  .bk-page-hero--detail .bk-detail__actions {
    justify-content: center;
  }
}

/* ========== 移动端全站优化 ========== */
@media (max-width: 768px) {
  :root {
    --bk-header-h: 60px;
  }

  .bk-container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .bk-main {
    padding: 16px 0 36px;
    min-height: calc(100vh - var(--bk-header-h) - 100px);
  }

  .bk-breadcrumb {
    font-size: 12px;
    gap: 6px;
    margin-bottom: 16px;
    line-height: 1.5;
  }

  .bk-page-hero {
    padding: 22px 18px;
    margin-bottom: 20px;
    border-radius: var(--bk-radius);
  }

  .bk-page-hero--compact {
    padding: 18px 16px;
    margin-bottom: 16px;
  }

  .bk-page-hero h1 {
    font-size: 22px;
    margin-top: 6px;
  }

  .bk-page-hero p {
    font-size: 14px;
  }

  .bk-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .bk-layout__side {
    order: 2;
  }

  .bk-layout__main {
    min-width: 0;
  }

  .bk-panel {
    border-radius: var(--bk-radius);
    margin-bottom: 18px;
  }

  .bk-panel__head {
    padding: 14px 16px;
    font-size: 16px;
  }

  .bk-panel__body {
    padding: 16px;
  }

  .bk-panel--filters .bk-filters,
  .bk-filters {
    padding: 14px 16px;
    margin-bottom: 16px;
    border-radius: var(--bk-radius);
  }

  .bk-filter-row {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    padding: 12px 0;
  }

  .bk-filter-label {
    width: auto;
    font-size: 13px;
    padding-top: 0;
  }

  .bk-filter-tags {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: 8px;
    margin: 0 -4px;
    padding: 2px 4px 6px;
    scrollbar-width: none;
  }

  .bk-filter-tags::-webkit-scrollbar {
    display: none;
  }

  .bk-filter-tags a {
    flex: 0 0 auto;
    padding: 8px 14px;
    font-size: 13px;
    white-space: nowrap;
  }

  .bk-sort {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    gap: 8px;
    margin-bottom: 18px;
    padding-bottom: 4px;
    scrollbar-width: none;
  }

  .bk-sort::-webkit-scrollbar {
    display: none;
  }

  .bk-sort a {
    flex: 0 0 auto;
    white-space: nowrap;
    padding: 8px 14px;
    font-size: 13px;
  }

  .bk-home-block__grid--page {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .bk-home-block__grid--page .bk-home-card {
    display: grid;
    grid-template-columns: 108px 1fr;
    gap: 0;
    align-items: stretch;
  }

  .bk-home-block__grid--page .bk-home-card__cover {
    aspect-ratio: 2 / 3;
    min-height: 100%;
    border-radius: var(--bk-radius) 0 0 var(--bk-radius);
  }

  .bk-home-block__grid--page .bk-home-card__body {
    padding: 12px 14px;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }

  .bk-home-block__grid--page .bk-home-card__body h3 {
    font-size: 15px;
    -webkit-line-clamp: 2;
  }

  .bk-home-block__grid--page .bk-home-card__desc {
    -webkit-line-clamp: 2;
    font-size: 12px;
    margin-bottom: 8px;
  }

  .bk-home-block__grid--page .bk-home-card:hover {
    transform: none;
  }

  .bk-detail__title {
    font-size: 22px;
  }

  .bk-detail__meta {
    justify-content: center;
    gap: 10px 14px;
    font-size: 12px;
  }

  .bk-detail__desc {
    font-size: 14px;
    text-align: left;
  }

  .bk-detail__actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }

  .bk-detail__actions .bk-home-btn {
    width: 100%;
    justify-content: center;
    min-height: 44px;
  }

  .bk-page-hero--detail.bk-detail {
    padding: 20px 16px;
    gap: 20px;
  }

  .bk-chapter-vol__toggle {
    padding: 12px 16px;
    font-size: 14px;
  }

  .bk-chapter-list a {
    padding: 12px 16px;
    font-size: 14px;
    gap: 10px;
  }

  .bk-chapter-list a span:first-child {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .bk-pagination {
    margin-top: 24px;
  }

  .bk-pagination .pagination > li > a,
  .bk-pagination .pagination > li > span {
    padding: 8px 12px;
    font-size: 13px;
  }

  .bk-empty {
    padding: 48px 20px;
  }

  .bk-footer {
    padding: 28px 0 20px;
    padding-bottom: calc(20px + env(safe-area-inset-bottom, 0px));
  }

  .bk-back-top {
    right: 16px;
    bottom: calc(72px + env(safe-area-inset-bottom, 0px));
    width: 40px;
    height: 40px;
  }

  body.bk-page-home .bk-back-top {
    bottom: calc(20px + env(safe-area-inset-bottom, 0px));
  }

  .bk-read-toolbar {
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }

  .bk-cat-hero {
    padding: 28px 18px;
    margin-bottom: 20px;
  }

  .bk-cat-hero h1 {
    font-size: 22px;
  }

  .bk-home-block {
    padding: 32px 0;
  }

  .bk-home-block--inner {
    padding: 4px 0 28px;
  }

  .bk-home-block .bk-container {
    overflow: visible;
  }

  .bk-home-block__head {
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    align-items: center;
    gap: 10px 12px;
    margin-bottom: 16px;
  }

  .bk-home-block__index {
    grid-row: 1 / 3;
    grid-column: 1;
    font-size: 32px;
    align-self: center;
  }

  .bk-home-block__titles {
    grid-column: 2;
    grid-row: 1;
    min-width: 0;
  }

  .bk-home-block__titles h2 {
    font-size: 20px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .bk-home-block__titles p {
    display: none;
  }

  .bk-home-block__head > .bk-home-link {
    grid-column: 2;
    grid-row: 2;
    justify-self: start;
    margin-top: 0;
  }

  .bk-home-block__tabs-wrap {
    position: relative;
    margin: 0 -16px 18px;
    overflow: hidden;
  }

  .bk-home-block__tabs-wrap::before,
  .bk-home-block__tabs-wrap::after {
    content: "";
    position: absolute;
    top: 0;
    bottom: 10px;
    width: 24px;
    z-index: 2;
    pointer-events: none;
  }

  .bk-home-block__tabs-wrap::before {
    left: 0;
    background: linear-gradient(90deg, var(--bk-tabs-fade, var(--bk-paper)) 30%, transparent);
  }

  .bk-home-block__tabs-wrap::after {
    right: 0;
    background: linear-gradient(270deg, var(--bk-tabs-fade, var(--bk-paper)) 30%, transparent);
  }

  .bk-home-block:nth-child(even) .bk-home-block__tabs-wrap::before,
  .bk-home-block:nth-child(even) .bk-home-block__tabs-wrap::after {
    --bk-tabs-fade: #fff;
  }

  .bk-home-block__tabs {
    display: flex;
    flex-wrap: nowrap;
    align-items: stretch;
    gap: 8px;
    margin: 0;
    padding: 2px 16px 12px;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior-x: contain;
    scroll-snap-type: x mandatory;
    scroll-padding-inline: 16px;
    scrollbar-width: none;
    touch-action: pan-x;
  }

  .bk-home-block__tabs::-webkit-scrollbar {
    display: none;
    height: 0;
  }

  .bk-home-block__tabs a {
    flex: 0 0 auto;
    scroll-snap-align: start;
    padding: 10px 18px;
    min-height: 40px;
    font-size: 14px;
    box-shadow: 0 1px 2px rgba(15, 20, 25, 0.04);
  }

  .bk-home-block__grid:not(.bk-home-block__grid--page) {
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
  }

  .bk-home-hero__title {
    font-size: clamp(20px, 6vw, 26px);
  }

  .bk-home-hero__desc {
    font-size: 14px;
    -webkit-line-clamp: 3;
  }

  .bk-home-hero__actions {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
    margin-left: auto;
    margin-right: auto;
  }

  .bk-home-hero__actions .bk-home-btn {
    width: 100%;
    justify-content: center;
    min-height: 44px;
  }

  .bk-home-hero__arrow {
    width: 40px;
    height: 40px;
  }

  .bk-home-channel__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .bk-home-channel__card {
    padding: 14px 12px;
  }

  .bk-home-rank__scroll {
    margin: 0 -16px;
    padding: 0 16px 8px;
  }

  .bk-home-rank__item {
    flex: 0 0 240px;
  }

  .bk-home-cta__inner {
    padding: 28px 20px;
    gap: 20px;
  }

  .bk-home-cta__text h2 {
    font-size: 22px;
  }

  .bk-home-cta .bk-home-btn {
    width: 100%;
    justify-content: center;
    min-height: 44px;
  }

  .bk-home-link {
    font-size: 13px;
    white-space: nowrap;
  }
}

@media (max-width: 480px) {
  .bk-header__row {
    min-height: 56px;
  }

  .bk-logo img {
    max-height: 36px;
    width: auto;
  }

  .bk-user__guest {
    gap: 6px;
  }

  .bk-user__btn {
    padding: 8px 12px;
    font-size: 13px;
    min-height: 36px;
  }

  .bk-user__logged .bk-user__trigger {
    padding: 4px 8px 4px 4px;
  }

  .bk-home-channel__grid {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }

  .bk-home-channel__name {
    font-size: 13px;
  }

  .bk-home-block__grid:not(.bk-home-block__grid--page) {
    grid-template-columns: 1fr;
  }

  .bk-home-block__grid:not(.bk-home-block__grid--page) .bk-home-card {
    display: grid;
    grid-template-columns: 100px 1fr;
  }

  .bk-home-block__grid:not(.bk-home-block__grid--page) .bk-home-card__cover {
    border-radius: var(--bk-radius) 0 0 var(--bk-radius);
  }

  .bk-home-block__grid:not(.bk-home-block__grid--page) .bk-home-card__body {
    padding: 12px 14px;
  }

  .bk-home-hero__cover {
    max-width: 160px;
  }

  .bk-home-hero__meta {
    flex-direction: column;
    gap: 6px;
    font-size: 13px;
  }

  .bk-home-rank__item {
    flex: 0 0 220px;
  }

  .bk-buy-box.bk-page-hero {
    padding: 22px 16px 20px;
  }

  .bk-buy-box.bk-page-hero h1 {
    font-size: 20px;
    margin-bottom: 18px;
    padding-bottom: 18px;
  }
}