:root {
  --primary-color: #e9302d;
  --text-color: #1f1f1f;
  --muted-color: #666;
  --line-color: #ececec;
  --paper-color: #fff;
  --soft-color: #faf7f2;
  --dark-color: #15171d;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text-color);
  background: #fff;
  font-family: "Outfit", "PingFang SC", "Microsoft YaHei", sans-serif;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line-color);
  backdrop-filter: blur(12px);
}

.header-shell,
.section-shell {
  width: min(1240px, calc(100% - 40px));
  margin: 0 auto;
}

.header-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  gap: 20px;
}

.brand img {
  width: 180px;
  height: auto;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 34px;
}

.site-nav a {
  position: relative;
  font-size: 20px;
  font-weight: 700;
  color: #333;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -10px;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: left;
  background: var(--primary-color);
  transition: transform 180ms ease;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--primary-color);
}

.site-nav a:hover::after,
.site-nav a.is-active::after {
  transform: scaleX(1);
}

.menu-toggle {
  display: none;
  padding: 10px 14px;
  border: 1px solid var(--line-color);
  border-radius: 8px;
  background: #fff;
}

.hero-panel {
  position: relative;
  min-height: clamp(460px, 66vh, 720px);
}

.hero-media {
  width: 100%;
  height: clamp(460px, 66vh, 720px);
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(16, 18, 24, 0.58) 0%, rgba(16, 18, 24, 0.32) 46%, rgba(16, 18, 24, 0.18) 100%),
    linear-gradient(180deg, rgba(16, 18, 24, 0.06) 0%, rgba(16, 18, 24, 0.42) 100%);
}

.hero-content {
  position: absolute;
  left: 50%;
  top: 50%;
  width: min(1240px, calc(100% - 40px));
  transform: translate(-50%, -42%);
  color: #fff;
  max-width: 1240px;
}

.hero-kicker,
.section-kicker {
  margin: 0 0 14px;
  color: var(--primary-color);
  font-size: 14px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 700;
}

.hero-content h1 {
  margin: 0;
  font-family: "Noto Serif SC", serif;
  font-size: clamp(42px, 6.2vw, 80px);
  line-height: 1.08;
  letter-spacing: -0.04em;
  white-space: nowrap;
}

.hero-title-divider {
  width: 72px;
  height: 4px;
  margin-top: 20px;
  border-radius: 999px;
  background: linear-gradient(90deg, #ff8a62, #ffd07f);
}

.hero-title-tagline {
  display: inline-block;
  margin: 18px 0 0;
  padding: 8px 14px;
  border-left: 3px solid #ff8d6b;
  border-radius: 0 12px 12px 0;
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 244, 231, 0.95);
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.35;
  font-weight: 600;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.hero-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
}

.tabs-strip {
  background: #fff;
  border-bottom: 1px solid var(--line-color);
}

.tabs-list {
  display: flex;
  align-items: center;
  gap: 36px;
  min-height: 64px;
  overflow-x: auto;
}

.tabs-list a {
  white-space: nowrap;
  font-size: 18px;
  font-weight: 700;
  color: #333;
}

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

.text-panel,
.content-panel {
  padding: 84px 0;
}

.text-panel {
  background: linear-gradient(180deg, #fff 0%, #faf7f2 100%);
}

.text-panel-accent,
.alt-panel {
  background: #fff;
}

.intro-layout {
  display: grid;
  grid-template-columns: minmax(240px, 0.42fr) minmax(0, 1fr);
  gap: 28px;
}

.features-section {
  display: grid;
  gap: 24px;
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
}

.features-section .panel-title h2 {
  max-width: none;
}

.intro-section {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
}

.intro-timeline {
  position: relative;
  display: grid;
  gap: 20px;
  padding-left: 28px;
}

.intro-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 12px;
  bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, #efb770, #f3e4cf);
}

.intro-item {
  position: relative;
  display: grid;
  grid-template-columns: 20px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.intro-marker {
  position: relative;
  z-index: 1;
  width: 18px;
  height: 18px;
  margin-top: 8px;
  border-radius: 999px;
  background: linear-gradient(135deg, #e9302d, #f0b86e);
  box-shadow: 0 0 0 6px rgba(249, 239, 223, 0.98);
}

.intro-card {
  padding: 22px 24px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line-color);
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.06);
}

.intro-card h3 {
  margin: 0 0 10px;
  color: var(--primary-color);
  font-size: 18px;
  letter-spacing: 0.04em;
}

.intro-card p {
  margin: 0;
  color: var(--muted-color);
  line-height: 1.9;
  font-size: 16px;
}

.panel-title h2,
.content-head h2 {
  margin: 0;
  font-family: "Noto Serif SC", serif;
  font-size: clamp(36px, 4vw, 58px);
  line-height: 1.1;
}

.panel-copy,
.brand-proof-copy {
  display: grid;
  gap: 18px;
}

.features-list {
  display: grid;
  gap: 18px;
  padding-left: 28px;
}

.panel-copy article,
.brand-proof-block {
  padding: 22px 24px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid var(--line-color);
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.06);
}

.panel-copy h3,
.brand-proof-block h4,
.series-copy h3 {
  margin: 0 0 10px;
  color: var(--primary-color);
  font-size: 18px;
  letter-spacing: 0.04em;
}

.panel-copy p,
.brand-proof-block p,
.series-copy p,
.content-head p {
  margin: 0;
  color: var(--muted-color);
  line-height: 1.9;
  font-size: 16px;
}

.feature-ribbon {
  padding: 22px 24px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line-color);
  box-shadow: 0 16px 34px rgba(0, 0, 0, 0.06);
}

.feature-ribbon::before {
  content: none;
}

.feature-ribbon h3 {
  margin: 0 0 10px;
  color: var(--primary-color);
  font-size: 18px;
  letter-spacing: 0.04em;
}

.feature-ribbon p {
  margin: 0;
  color: var(--muted-color);
  line-height: 1.9;
  font-size: 16px;
}

.feature-strip {
  padding: 0 0 84px;
  background: linear-gradient(180deg, #faf7f2 0%, #fff 100%);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  padding: 24px;
  min-height: 240px;
  border-radius: 24px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(250, 247, 242, 0.96));
  border: 1px solid var(--line-color);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.05);
}

.feature-index {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--primary-color);
  font-size: 13px;
  letter-spacing: 0.18em;
}

.feature-card h3 {
  margin: 0 0 10px;
  font-family: "Noto Serif SC", serif;
  font-size: 28px;
}

.feature-card p {
  margin: 0;
  color: var(--muted-color);
  line-height: 1.85;
}

.content-head {
  display: grid;
  grid-template-columns: minmax(240px, 0.42fr) minmax(0, 1fr);
  gap: 28px;
  margin-bottom: 24px;
  align-items: end;
}

.series-row {
  display: grid;
  grid-template-columns: minmax(300px, 0.85fr) minmax(0, 1.15fr);
  gap: 20px;
  padding: 22px 0;
  border-top: 1px solid var(--line-color);
}

.series-row:first-of-type {
  border-top: 0;
}

.series-copy {
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 18px 0;
}

.series-media {
  display: grid;
  gap: 14px;
}

.series-media > img,
.series-media-grid img,
.review-gallery img,
.cooperation-media img {
  width: 100%;
  border-radius: 22px;
  border: 1px solid var(--line-color);
  background: #fff;
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.05);
}

.series-media-grid {
  display: grid;
  gap: 14px;
}

.series-media-grid img {
  min-height: 240px;
  object-fit: contain;
  background: linear-gradient(180deg, rgba(255, 250, 242, 0.92), rgba(246, 241, 234, 0.9));
}

.series-media-grid-compact {
  grid-template-columns: repeat(3, minmax(0, 180px));
  justify-content: start;
}

.series-media-grid-compact img {
  min-height: 180px;
}

.three-up {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.two-up {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.four-up {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.series-media-grid-priority {
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  align-items: start;
}

.series-media-grid-priority-large {
  grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.6fr) minmax(0, 0.7fr);
  align-items: start;
}

.series-media-grid-priority .is-feature,
.series-media-grid-priority-large .is-feature {
  min-height: 320px;
}

.series-media-grid-priority .is-wide-feature {
  min-height: 280px;
}

.catalog-panel .series-row {
  align-items: stretch;
}

.catalog-panel .series-media,
.catalog-panel .series-media-grid {
  gap: 14px;
  height: 100%;
  align-items: stretch;
  align-content: center;
}

.catalog-panel .series-media-grid {
  grid-auto-rows: minmax(0, 1fr);
}

.catalog-panel .series-media-grid-compact {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.catalog-panel .series-media-grid-compact,
.catalog-panel .three-up {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.catalog-panel .four-up {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  height: auto;
  align-self: start;
  align-content: start;
  grid-auto-rows: auto;
}

.catalog-panel .series-row.is-quad .series-media {
  max-width: 400px;
  width: 100%;
  justify-self: center;
}

.catalog-panel .series-row.is-quad .four-up {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  width: 100%;
  gap: 10px;
}

.catalog-panel .series-media-grid-compact .book-card,
.catalog-panel .three-up .book-card {
  aspect-ratio: 5 / 6.5;
}

.catalog-panel .four-up .book-card {
  aspect-ratio: 5 / 6.2;
}

.catalog-panel .series-row.is-quad .four-up .book-card {
  aspect-ratio: 5 / 6.6;
}

.catalog-panel .series-media-grid-compact .book-card img,
.catalog-panel .three-up .book-card img {
  width: 100%;
  height: 100%;
}

.catalog-panel .four-up .book-card img {
  width: 100%;
  height: 100%;
}

.catalog-panel .series-row-compact-books .series-media-grid-compact {
  gap: 8px;
}

.catalog-panel .series-row-compact-books .series-media-grid-compact .book-card {
  aspect-ratio: 5 / 6.4;
}

.catalog-panel .series-media-grid-priority,
.catalog-panel .series-media-grid-priority-large {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: stretch;
}

.catalog-panel .book-card {
  margin: 0;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
  height: 100%;
  min-height: 0;
  padding: clamp(10px, 2vw, 16px);
  border-radius: 22px;
  border: 1px solid rgba(196, 176, 149, 0.42);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.98) 0%, rgba(249, 244, 236, 0.96) 100%);
  box-shadow:
    0 16px 30px rgba(21, 23, 29, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.85);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.catalog-panel .book-card::before {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 16px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.9), rgba(246, 238, 228, 0.72));
  border: 1px solid rgba(255, 255, 255, 0.72);
  pointer-events: none;
}

.catalog-panel .book-card:hover {
  transform: translateY(-4px);
  border-color: rgba(204, 168, 117, 0.55);
  box-shadow:
    0 22px 40px rgba(21, 23, 29, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

.catalog-panel .book-card img {
  position: relative;
  z-index: 1;
  width: auto;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  min-height: 0;
  object-fit: contain;
  border: 0;
  border-radius: 14px;
  background: transparent;
  box-shadow: none;
  filter: drop-shadow(0 14px 18px rgba(58, 41, 21, 0.12));
}

.catalog-panel .series-media > .book-card,
.catalog-panel .two-up .book-card {
  aspect-ratio: 5 / 6.6;
}

.catalog-panel .series-row.is-single .series-media > .book-card {
  aspect-ratio: 5 / 6.9;
  width: 100%;
  max-width: min(100%, 312px);
  max-height: 420px;
  justify-self: center;
}

.catalog-panel .series-row.is-pair .two-up .book-card,
.catalog-panel .series-row.is-grid .book-card {
  max-width: none;
  max-height: none;
}

.catalog-panel .two-up {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.catalog-panel .three-up,
.catalog-panel .series-media-grid-compact,
.catalog-panel .two-up {
  align-items: stretch;
}

.review-gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.review-gallery img {
  object-fit: cover;
}

.cooperation-panel {
  padding: 84px 0 96px;
  background: linear-gradient(135deg, #171a22 0%, #1f2d44 48%, #2b3c5f 100%);
}

.content-head-light h2,
.content-head-light p,
.cooperation-panel .section-kicker {
  color: #fff;
}

.content-head-light .section-kicker {
  color: #ff7a70;
}

.cooperation-media img {
  max-width: 920px;
  margin: 0 auto;
}

.site-footer {
  padding: 18px 0 30px;
  background: #fff;
}

.footer-shell {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: #777;
  font-size: 14px;
}

.footer-shell img {
  width: 92px;
}

.footer-shell p {
  margin: 0;
}

.footer-record {
  color: #8a8176;
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 40;
  width: 54px;
  height: 54px;
  border: 0;
  border-radius: 50%;
  background: var(--primary-color);
  color: #fff;
  letter-spacing: 0.08em;
  cursor: pointer;
  box-shadow: 0 12px 26px rgba(233, 48, 45, 0.28);
  opacity: 0;
  pointer-events: none;
}

.back-top.is-visible {
  opacity: 1;
  pointer-events: auto;
}

@media (max-width: 1100px) {
  .feature-grid,
  .two-up,
  .three-up,
  .four-up,
  .series-media-grid-priority,
  .series-media-grid-priority-large,
  .review-gallery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .catalog-panel .series-media-grid-compact {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .catalog-panel .three-up {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .catalog-panel .four-up {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .catalog-panel .series-row.is-single .series-media > .book-card {
    max-width: min(100%, 284px);
    max-height: 390px;
  }

  .catalog-panel .series-row.is-quad .series-media {
    max-width: 380px;
  }

  .catalog-panel .series-row.is-quad .four-up {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .intro-layout,
  .content-head,
  .series-row {
    grid-template-columns: 1fr;
  }

  .series-copy {
    padding: 0;
  }
}

@media (max-width: 860px) {
  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 100%;
    display: none;
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding: 18px;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--line-color);
    border-radius: 18px;
    box-shadow: 0 16px 34px rgba(0, 0, 0, 0.08);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    font-size: 17px;
  }

  .hero-panel,
  .hero-media {
    min-height: clamp(400px, 58vh, 560px);
    height: clamp(400px, 58vh, 560px);
  }

  .intro-section {
    width: min(1240px, calc(100% - 28px));
  }

  .intro-timeline {
    gap: 16px;
    padding-left: 22px;
  }

  .intro-timeline::before {
    left: 6px;
  }

  .intro-item {
    grid-template-columns: 16px minmax(0, 1fr);
    gap: 12px;
  }

  .intro-marker {
    width: 14px;
    height: 14px;
    margin-top: 10px;
    box-shadow: 0 0 0 5px rgba(249, 239, 223, 0.98);
  }

  .intro-card {
    padding: 18px;
    border-radius: 20px;
  }

  .features-section {
    gap: 18px;
    width: min(1240px, calc(100% - 28px));
  }

  .features-list {
    gap: 14px;
    padding-left: 22px;
  }

  .feature-ribbon {
    padding: 18px;
    border-radius: 20px;
  }

  .feature-ribbon::before {
    content: none;
  }

  .hero-content {
    transform: translate(-50%, -40%);
  }

  .hero-content h1 {
    font-size: clamp(36px, 9vw, 58px);
    white-space: nowrap;
  }

  .hero-title-divider {
    width: 56px;
    margin-top: 16px;
  }

  .hero-title-tagline {
    margin-top: 14px;
    padding: 7px 12px;
    font-size: clamp(18px, 4.4vw, 24px);
  }

  .tabs-list {
    gap: 24px;
  }

  .feature-grid,
  .three-up,
  .two-up,
  .series-media-grid-priority,
  .series-media-grid-priority-large,
  .review-gallery {
    grid-template-columns: 1fr;
  }

  .hero-panel,
  .hero-media {
    min-height: clamp(340px, 52vh, 460px);
    height: clamp(340px, 52vh, 460px);
  }

  .hero-content {
    top: 50%;
    transform: translate(-50%, -38%);
  }

  .hero-actions {
    gap: 8px;
    margin-top: 18px;
  }

  .series-media-grid-compact {
    grid-template-columns: 1fr;
  }

  .catalog-panel .four-up {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .catalog-panel .series-row.is-quad .series-media {
    max-width: 320px;
  }

  .catalog-panel .series-row.is-quad .four-up {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .catalog-panel .book-card {
    min-height: 220px;
    padding: 12px;
    border-radius: 18px;
  }

  .catalog-panel .book-card::before {
    inset: 7px;
    border-radius: 13px;
  }

  .catalog-panel .series-row.is-single .series-media > .book-card,
  .catalog-panel .two-up .book-card,
  .catalog-panel .four-up .book-card,
  .catalog-panel .three-up .book-card,
  .catalog-panel .series-media-grid-compact .book-card {
    aspect-ratio: 5 / 6.3;
  }

  .catalog-panel .four-up .book-card {
    min-height: 0;
    aspect-ratio: 5 / 6.7;
  }

  .catalog-panel .series-row.is-single .series-media > .book-card {
    max-width: min(100%, 248px);
    max-height: 340px;
  }

  .text-panel,
  .content-panel,
  .cooperation-panel {
    padding: 64px 0;
  }
}