/* ==========================================================================
   DeepSeek AI - 敦煌色彩与数字壁画专属样式系统
   Style: Dunhuang Futuristic Palette, Sand Gold & Malachite Green, Digital Fresco & Smart Textures
   ========================================================================== */

:root {
  --grotto-dark: #091312;
  --grotto-deep: #0e1e1b;
  --grotto-card: rgba(18, 36, 33, 0.75);
  --grotto-card-hover: rgba(24, 48, 44, 0.88);
  
  --sand-gold: #e5c158;
  --sand-gold-light: #f6e29a;
  --sand-gold-glow: rgba(229, 193, 88, 0.22);
  --malachite-green: #238b72;
  --mineral-jade: #3dd5ad;
  --mineral-ochre: #c96b42;
  
  --line-gold: rgba(229, 193, 88, 0.25);
  --line-jade: rgba(61, 213, 173, 0.2);
  --fresco-border: rgba(229, 193, 88, 0.16);
  
  --fresco-paper: #f8faf9;
  --sand-text: #e2e8e5;
  --stone-muted: #95a5a1;
  --ochre-muted: #d4a373;
  
  --shadow-grotto: 0 24px 64px -12px rgba(0, 0, 0, 0.55);
  --shadow-gold: 0 0 35px -5px rgba(229, 193, 88, 0.18);
  
  --font-fresco: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Songti SC", "Noto Serif SC", "PingFang SC", "Microsoft YaHei", serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-code: "JetBrains Mono", Consolas, "SF Mono", monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--sand-text);
  background-color: var(--grotto-dark);
  line-height: 1.8;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
}

/* 敦煌数字壁画岩彩与沙金微粒肌理 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(circle at 18% 15%, rgba(35, 139, 114, 0.14) 0%, transparent 45%),
    radial-gradient(circle at 82% 20%, rgba(229, 193, 88, 0.12) 0%, transparent 42%),
    radial-gradient(circle at 50% 85%, rgba(201, 107, 66, 0.08) 0%, transparent 48%),
    radial-gradient(rgba(229, 193, 88, 0.12) 1px, transparent 1.6px),
    linear-gradient(rgba(35, 139, 114, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(35, 139, 114, 0.03) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 100% 100%, 40px 40px, 80px 80px, 80px 80px;
  opacity: 0.9;
}

/* 飞天飘带般的全息光带 */
body::after {
  content: "";
  position: fixed;
  top: -15vh;
  right: -10vw;
  width: 55vw;
  height: 55vw;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(229, 193, 88, 0.07) 0%, rgba(35, 139, 114, 0.04) 40%, transparent 70%);
  filter: blur(60px);
  pointer-events: none;
  z-index: -1;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: all 0.28s ease;
}

.container {
  width: min(1180px, calc(100% - 44px));
  margin: 0 auto;
}

/* 顶栏：敦煌金翠殿堂导航台 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(9, 19, 18, 0.86);
  border-bottom: 1px solid var(--fresco-border);
  backdrop-filter: blur(20px);
}

.nav {
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand img {
  width: 130px;
  filter: drop-shadow(0 0 14px rgba(229, 193, 88, 0.35));
}

.brand-fresco-badge {
  font-family: var(--font-code);
  font-size: 11px;
  color: var(--sand-gold);
  padding: 3px 10px;
  border-radius: 4px;
  border: 1px solid var(--line-gold);
  background: rgba(229, 193, 88, 0.08);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  gap: 8px;
  padding: 5px;
  border: 1px solid var(--fresco-border);
  border-radius: 999px;
  background: rgba(14, 30, 27, 0.72);
  box-shadow: inset 0 0 14px rgba(229, 193, 88, 0.05);
}

.nav-links a {
  padding: 8px 18px;
  border-radius: 999px;
  color: var(--stone-muted);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.nav-links a.active,
.nav-links a:hover {
  color: #081211;
  background: linear-gradient(135deg, var(--sand-gold), var(--mineral-jade));
  box-shadow: 0 0 16px rgba(229, 193, 88, 0.4);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: #071311;
  background: linear-gradient(135deg, var(--sand-gold) 0%, #f6df94 50%, var(--mineral-jade) 100%);
  border: 1px solid var(--sand-gold);
  box-shadow: 0 0 22px rgba(229, 193, 88, 0.3);
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(229, 193, 88, 0.5);
}

.btn.ghost {
  color: var(--sand-gold-light);
  background: rgba(229, 193, 88, 0.06);
  border: 1px solid var(--line-gold);
  box-shadow: none;
}

.btn.ghost:hover {
  background: rgba(229, 193, 88, 0.14);
  border-color: var(--sand-gold);
}

.btn.emerald {
  color: #ffffff;
  background: linear-gradient(135deg, #165b4c 0%, #238b72 100%);
  border: 1px solid var(--mineral-jade);
  box-shadow: 0 0 20px rgba(35, 139, 114, 0.35);
}

.btn.emerald:hover {
  box-shadow: 0 0 28px rgba(35, 139, 114, 0.55);
}

/* 主屏 Hero 区域 */
.hero {
  padding: 90px 0 66px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  align-items: center;
  gap: 54px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 22px;
  font-family: var(--font-code);
  color: var(--sand-gold);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "DUNHUANG // DIGITAL FRESCO";
  color: var(--mineral-jade);
  opacity: 0.95;
}

.eyebrow::after {
  content: "";
  width: 40px;
  height: 1px;
  background: linear-gradient(90deg, var(--sand-gold), transparent);
}

h1, h2, h3 {
  margin: 0;
  color: #ffffff;
  line-height: 1.15;
  letter-spacing: -0.035em;
  font-family: var(--font-fresco);
  font-weight: 700;
}

h1 {
  font-size: clamp(40px, 6.6vw, 78px);
  text-shadow: 0 0 35px rgba(229, 193, 88, 0.22);
}

h2 {
  font-size: clamp(28px, 4vw, 48px);
}

h3 {
  font-size: 22px;
}

p {
  margin: 0;
  color: var(--stone-muted);
}

.lead {
  max-width: 660px;
  margin-top: 24px;
  font-size: 17px;
  line-height: 1.85;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 32px;
}

/* 敦煌数字壁画视窗卡片 */
.fresco-card-frame {
  position: relative;
  border: 1px solid var(--line-gold);
  border-radius: 36px;
  background: var(--grotto-card);
  backdrop-filter: blur(24px);
  padding: 24px;
  box-shadow: var(--shadow-grotto), var(--shadow-gold);
  transition: border-color 0.3s ease;
}

.fresco-card-frame::before {
  content: "";
  position: absolute;
  inset: 12px;
  border: 1px solid rgba(229, 193, 88, 0.12);
  border-radius: 26px;
  pointer-events: none;
}

.fresco-photo-wrap {
  position: relative;
  aspect-ratio: 4 / 3;
  border-radius: 24px;
  overflow: hidden;
  background: #0d1a18;
  border: 1px solid rgba(229, 193, 88, 0.25);
}

.fresco-photo-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fresco-photo-wrap:hover img {
  transform: scale(1.03);
}

.fresco-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.fresco-stat-cell {
  padding: 14px 16px;
  border: 1px solid var(--fresco-border);
  border-radius: 20px;
  background: rgba(10, 22, 20, 0.7);
}

.fresco-stat-cell strong {
  display: block;
  font-family: var(--font-code);
  font-size: 18px;
  color: var(--sand-gold-light);
  line-height: 1.1;
}

.fresco-stat-cell span {
  font-size: 12px;
  color: var(--stone-muted);
}

/* 标签胶囊体系 */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: var(--sand-gold-light);
  background: rgba(229, 193, 88, 0.08);
  border: 1px solid var(--line-gold);
}

.tag::before {
  content: "✦";
  font-size: 10px;
  color: var(--mineral-jade);
}

/* 核心板块 Section */
.section {
  padding: 80px 0;
  position: relative;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
  margin-bottom: 38px;
}

.section-head p {
  max-width: 520px;
  font-size: 16px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 26px;
}

.mural-card {
  position: relative;
  padding: 26px;
  border: 1px solid var(--fresco-border);
  border-radius: 30px;
  background: var(--grotto-card);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-grotto);
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.mural-card:hover {
  transform: translateY(-4px);
  border-color: var(--line-gold);
}

.mural-card img {
  margin-bottom: 20px;
  border-radius: 22px;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  background: #0d1a18;
  border: 1px solid rgba(229, 193, 88, 0.18);
}

.mural-card h3 {
  margin-bottom: 10px;
  color: #ffffff;
}

/* 沉静大屏聚焦壁画展台 */
.fresco-focus-block {
  padding: 44px;
  border-radius: 38px;
  border: 1px solid var(--line-gold);
  background:
    radial-gradient(circle at 85% 15%, rgba(229, 193, 88, 0.12), transparent 42%),
    radial-gradient(circle at 15% 85%, rgba(35, 139, 114, 0.12), transparent 40%),
    linear-gradient(155deg, rgba(18, 38, 35, 0.95), rgba(9, 19, 18, 0.98));
  box-shadow: var(--shadow-grotto), var(--shadow-gold);
}

/* 网页版入口页：丝路石窟全息舆图路线布局 */
.silk-road-layout {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 32px;
  align-items: start;
}

.silk-road-aside {
  position: sticky;
  top: 104px;
  padding: 34px;
  border-radius: 34px;
  border: 1px solid var(--line-gold);
  background: var(--grotto-card);
  backdrop-filter: blur(24px);
  box-shadow: var(--shadow-grotto);
}

.grotto-station-card {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 22px;
  align-items: center;
  margin-bottom: 20px;
  padding: 20px;
  border: 1px solid var(--fresco-border);
  border-radius: 28px;
  background: var(--grotto-card);
  backdrop-filter: blur(20px);
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.grotto-station-card:hover {
  border-color: var(--line-gold);
  transform: translateY(-2px);
}

.grotto-station-card img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 20px;
  background: #0d1a18;
  border: 1px solid rgba(229, 193, 88, 0.18);
}

/* 帮助中心页：藏经洞与智能问答录 */
.help-hero {
  padding: 78px 0 36px;
  text-align: center;
}

.help-hero .lead {
  margin-left: auto;
  margin-right: auto;
}

.search-fresco-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  width: min(760px, 100%);
  margin: 32px auto 0;
  padding: 8px;
  border: 1px solid var(--line-gold);
  border-radius: 999px;
  background: rgba(14, 30, 27, 0.9);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.search-fresco-wrap span {
  flex: 1;
  padding-left: 20px;
  color: var(--stone-muted);
  text-align: left;
  font-size: 14px;
}

.faq-fresco-stream {
  border-top: 1px solid var(--fresco-border);
}

.faq-fresco-item {
  display: grid;
  grid-template-columns: 0.38fr 0.62fr;
  gap: 32px;
  padding: 30px 0;
  border-bottom: 1px solid var(--fresco-border);
}

.faq-fresco-item h3 {
  color: #ffffff;
}

/* 页脚 */
.footer {
  margin-top: 84px;
  padding: 42px 0;
  border-top: 1px solid var(--fresco-border);
  background: rgba(7, 15, 14, 0.94);
}

.footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: var(--stone-muted);
  font-size: 14px;
}

.footer a {
  margin-left: 18px;
  color: var(--sand-text);
}

.footer a:hover {
  color: var(--sand-gold);
}

@media (max-width: 940px) {
  .nav {
    flex-wrap: wrap;
    padding: 14px 0;
  }

  .nav-links {
    order: 3;
    width: 100%;
    overflow-x: auto;
    justify-content: flex-start;
  }

  .hero-grid,
  .grid-2,
  .silk-road-layout,
  .faq-fresco-item {
    grid-template-columns: 1fr;
  }

  .silk-road-aside {
    position: relative;
    top: auto;
  }
}

@media (max-width: 680px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .grid-3,
  .fresco-stats-grid {
    grid-template-columns: 1fr;
  }

  .grotto-station-card {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 52px 0;
  }

  .footer-row,
  .section-head {
    display: block;
  }
}