/* ========================================
   六体计方 · 古法科技 视觉系统
   深色科技底 + 古代绢本暖色点缀
   ======================================== */

* { margin: 0; padding: 0; box-sizing: border-box; }

/* ---- 色彩系统 ---- */
:root {
  --bg-deep: #0A0F1F;
  --bg-card: rgba(20, 27, 51, 0.6);
  --parchment: #D4C5A0;
  --parchment-dim: #8B7D5B;
  --ink-light: #E8EDF5;
  --ink-muted: #9BA4C7;
  --ink-dim: #6B7AA8;
  --ink-secondary: #8B9BB4;
  --accent-cyan: #00D4FF;
  --accent-gold: #C9A96E;
  --border-dim: rgba(42, 59, 107, 0.3);
  --border-card: #2A3B6B;
  --font-title: 'Noto Serif SC', 'SimSun', 'STSong', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

body {
  background: var(--bg-deep);
  color: var(--ink-light);
  font-family: var(--font-body);
  line-height: 1.6;
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 60px;
  background: rgba(10, 15, 31, 0.88);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-dim);
  position: sticky;
  top: 0;
  z-index: 100;
}

.logo {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 2px 0;
}
.logo-icon { font-size: 22px; margin-right: 4px; }
.logo-title {
  font-family: var(--font-title);
  font-size: 22px;
  font-weight: 900;
  color: var(--accent-gold);
  letter-spacing: 4px;
}
.logo-subtitle {
  font-size: 15px;
  font-weight: 500;
  color: var(--accent-cyan);
  margin-left: 2px;
}
.logo-epoch {
  width: 100%;
  font-size: 11px;
  color: var(--parchment-dim);
  letter-spacing: 2px;
  margin-top: -1px;
  padding-left: 30px;
}

.nav-links a {
  color: var(--ink-muted);
  text-decoration: none;
  margin: 0 18px;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.3s;
  position: relative;
}
.nav-links a:hover { color: var(--accent-gold); }
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent-gold);
  transition: width 0.3s;
}
.nav-links a:hover::after { width: 100%; }

.nav-cta {
  background: linear-gradient(135deg, var(--accent-gold), #B8942E);
  color: var(--bg-deep) !important;
  padding: 8px 20px;
  border-radius: 30px;
  font-weight: 600 !important;
}
.nav-cta::after { display: none !important; }
.nav-cta:hover { box-shadow: 0 0 30px rgba(201, 168, 76, 0.35); }

.feedback-btn {
  background: rgba(201, 168, 76, 0.1);
  border: 1px solid rgba(201, 168, 76, 0.25);
  color: var(--accent-gold);
  padding: 8px 20px;
  border-radius: 30px;
  cursor: pointer;
  font-size: 14px;
  font-family: var(--font-body);
  transition: all 0.3s;
}
.feedback-btn:hover {
  background: rgba(201, 168, 76, 0.2);
  box-shadow: 0 0 20px rgba(201, 168, 76, 0.15);
}

/* ========================================
   首屏 Hero
   ======================================== */
.hero {
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* 古代舆图风格底纹 —— 计里画方网格 */
.hero-ancient-map-bg {
  position: absolute;
  inset: 0;
  background-image:
    /* 主线网格（粗线） */
    repeating-linear-gradient(
      0deg,
      rgba(139, 125, 91, 0.04) 0px,
      rgba(139, 125, 91, 0.04) 1px,
      transparent 1px,
      transparent 160px
    ),
    repeating-linear-gradient(
      90deg,
      rgba(139, 125, 91, 0.04) 0px,
      rgba(139, 125, 91, 0.04) 1px,
      transparent 1px,
      transparent 160px
    ),
    /* 子线网格（细线） */
    repeating-linear-gradient(
      0deg,
      rgba(139, 125, 91, 0.02) 0px,
      rgba(139, 125, 91, 0.02) 1px,
      transparent 1px,
      transparent 40px
    ),
    repeating-linear-gradient(
      90deg,
      rgba(139, 125, 91, 0.02) 0px,
      rgba(139, 125, 91, 0.02) 1px,
      transparent 1px,
      transparent 40px
    );
  animation: mapDrift 180s ease-in-out infinite alternate;
  transform-origin: center;
}

@keyframes mapDrift {
  0%   { transform: scale(1) rotate(0deg) translate(0, 0); }
  25%  { transform: scale(1.02) rotate(0.5deg) translate(10px, -8px); }
  50%  { transform: scale(1) rotate(0deg) translate(0, 0); }
  75%  { transform: scale(1.01) rotate(-0.3deg) translate(-6px, 6px); }
  100% { transform: scale(1) rotate(0deg) translate(0, 0); }
}

/* 科技粒子叠加（极淡） */
.hero-particle-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(1px 1px at 20% 30%, rgba(0, 212, 255, 0.08), transparent),
    radial-gradient(1px 1px at 50% 70%, rgba(0, 212, 255, 0.06), transparent),
    radial-gradient(1.5px 1.5px at 75% 20%, rgba(0, 212, 255, 0.07), transparent),
    radial-gradient(1px 1px at 30% 85%, rgba(201, 168, 76, 0.05), transparent),
    radial-gradient(1.5px 1.5px at 90% 60%, rgba(201, 168, 76, 0.06), transparent);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 860px;
  padding: 0 24px;
}

/* 顶部古文小引 */
.ancient-quote {
  font-family: var(--font-title);
  font-size: 16px;
  color: var(--parchment);
  letter-spacing: 4px;
  margin-bottom: 28px;
  opacity: 0.75;
  animation: fadeInUp 1s ease 0.2s both;
}

/* 主标题 —— 书法体 */
.hero-content h1 {
  font-family: var(--font-title);
  font-size: 52px;
  font-weight: 900;
  line-height: 1.3;
  letter-spacing: 8px;
  background: linear-gradient(135deg, #FFFFFF 0%, var(--accent-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: fadeInUp 1s ease 0.4s both;
}

/* 副标题 */
.hero-content .subtitle {
  font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
  font-size: 18px;
  font-weight: 300;
  color: var(--ink-secondary);
  margin: 24px 0 36px;
  line-height: 1.8;
  animation: fadeInUp 1s ease 0.6s both;
}

.hero-content .subtitle strong {
  color: var(--accent-cyan);
  font-weight: 500;
}

/* 按钮 */
.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease 0.8s both;
}

.btn-primary, .btn-ghost {
  display: inline-block;
  padding: 14px 40px;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  transition: all 0.4s;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), #0070B3);
  color: var(--bg-deep);
  box-shadow: 0 4px 24px rgba(0, 212, 255, 0.25);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 40px rgba(0, 212, 255, 0.4);
}

.btn-ghost {
  border: 1.5px solid rgba(201, 169, 110, 0.35);
  color: var(--accent-gold);
  background: rgba(201, 169, 110, 0.04);
}
.btn-ghost:hover {
  background: rgba(201, 169, 110, 0.1);
  border-color: var(--accent-gold);
  transform: translateY(-2px);
}

/* 信任数据 */
.trust-text {
  margin-top: 42px;
  font-size: 14px;
  color: var(--ink-dim);
  letter-spacing: 2px;
  animation: fadeInUp 1s ease 1s both;
}
.trust-text strong {
  color: var(--accent-cyan);
  font-weight: 700;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ========================================
   卖点卡片 · 制图六法
   ======================================== */
.features {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 80px 60px;
  border-top: 1px solid var(--border-dim);
  position: relative;
}

.section-label {
  font-family: var(--font-title);
  font-size: 13px;
  color: var(--accent-gold);
  letter-spacing: 6px;
  text-transform: uppercase;
  margin-bottom: 40px;
  padding: 6px 24px;
  border: 1px solid rgba(201, 168, 76, 0.2);
  border-radius: 30px;
  background: rgba(201, 168, 76, 0.04);
}

.features::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-gold), transparent);
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 16px;
  padding: 32px 28px;
  max-width: 320px;
  transition: all 0.4s;
}
.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(201, 168, 76, 0.06);
  border-color: rgba(201, 168, 76, 0.2);
}
.card-epigraph {
  font-family: var(--font-title);
  font-size: 12px;
  color: var(--accent-gold);
  letter-spacing: 3px;
  margin-bottom: 14px;
  padding-bottom: 6px;
  display: inline-block;
  border-bottom: 1px solid rgba(201, 169, 110, 0.25);
}
.feature-card .icon { font-size: 36px; margin-bottom: 12px; }
.feature-card h3 { font-size: 20px; color: var(--accent-cyan); margin-bottom: 10px; font-weight: 600; }
.feature-card p { color: var(--ink-muted); line-height: 1.6; font-size: 15px; }

/* 响应式：大屏显示三列 */
@media (min-width: 900px) {
  .features {
    flex-direction: row;
    justify-content: center;
    gap: 40px;
  }
  .section-label {
    position: absolute;
    top: 36px;
    left: 50%;
    transform: translateX(-50%);
    margin-bottom: 0;
  }
  .features .feature-card {
    margin-top: 60px;
  }
}

/* ========================================
   幻灯片演示区 · 学古通今（PPT动画效果）
   ======================================== */
.video-section {
  padding: 80px 60px;
  text-align: center;
  border-top: 1px solid var(--border-dim);
}
.video-section h2 {
  font-family: var(--font-title);
  font-size: 32px;
  font-weight: 700;
  color: var(--ink-light);
  letter-spacing: 4px;
}
.video-tabs { margin: 28px 0; }
.tab-btn {
  background: transparent;
  border: 1px solid var(--border-card);
  color: var(--ink-muted);
  padding: 10px 30px;
  border-radius: 30px;
  margin: 0 8px;
  cursor: pointer;
  font-size: 14px;
  font-family: var(--font-body);
  transition: all 0.3s;
}
.tab-btn.active {
  background: linear-gradient(135deg, var(--accent-gold), #B8942E);
  color: var(--bg-deep);
  border-color: var(--accent-gold);
  font-weight: 600;
}
.tab-btn:not(.active):hover {
  border-color: var(--accent-gold);
  color: var(--accent-gold);
}

/* ---- 幻灯片容器 ---- */
.slider {
  position: relative;
  z-index: 1;
  width: min(1100px, 92vw);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* 图片舞台（基准 900px 宽；较窄屏幕自动缩放并保持 16:9，640px 以下见断点改 4:3） */
.stage {
  position: relative;
  width: min(900px, 100%);
  aspect-ratio: 16 / 9;
  height: auto;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid rgba(0, 212, 255, 0.25);
  border-radius: 16px;
  overflow: hidden;
  backdrop-filter: blur(12px);
  box-shadow:
    0 0 40px rgba(0, 212, 255, 0.08),
    inset 0 0 60px rgba(0, 212, 255, 0.03);
  cursor: pointer; /* 点击暂停/继续 */
}

/* 全屏模式：放大至视口的 80%，保持 16:9 居中（线框/文字由 JS 按比例缩放） */
.stage.fullscreen {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: min(80vw, 142.22vh);
  height: min(80vh, 45vw);
  margin: 0;
  background: #0A0F1F;
  z-index: 1000;
  box-shadow: 0 0 0 100vmax rgba(0, 0, 0, 0.65); /* 四周遮罩，聚焦展示 */
}

/* 四角装饰 */
.stage .corner {
  position: absolute;
  width: 24px; height: 24px;
  border: 2px solid var(--accent-cyan);
  opacity: 0.7;
  z-index: 5;
}
.corner.tl { top: 10px; left: 10px; border-right: none; border-bottom: none; }
.corner.tr { top: 10px; right: 10px; border-left: none; border-bottom: none; }
.corner.bl { bottom: 10px; left: 10px; border-right: none; border-top: none; }
.corner.br { bottom: 10px; right: 10px; border-left: none; border-top: none; }

/* 幻灯片图片 */
.slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.6s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}
.slide.active { opacity: 1; }

.slide img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 24px;
}

/* 标注动画（文字+线框，随每张图片依次弹出） */
.anno-box {
  position: absolute;
  border: 2px solid;
  border-radius: 4px;
  opacity: 0;
  transform: scale(0.5);
  animation: anno-box-in 0.45s ease forwards;
  pointer-events: none;
}
@keyframes anno-box-in {
  from { opacity: 0; transform: scale(0.5); }
  to { opacity: 1; transform: scale(1); }
}
.anno-text {
  position: absolute;
  opacity: 0;
  background: rgba(10, 15, 31, 0.75);
  padding: 0.15em 0.7em; /* em 单位：随字号同比例缩放 */
  border-radius: 0.3em;
  white-space: nowrap;
  animation: anno-text-in 0.45s ease forwards;
  pointer-events: none;
}
@keyframes anno-text-in {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}
/* 悬停暂停：冻结标注的弹出动画 */
.stage.paused .anno-box,
.stage.paused .anno-text {
  animation-play-state: paused;
}
/* 暂停状态提示 */
.stage.paused::after {
  content: '⏸ 已暂停 · 点击继续';
  position: absolute;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(10, 15, 31, 0.85);
  color: #C9A96E;
  font-size: 12px;
  padding: 4px 14px;
  border-radius: 20px;
  border: 1px solid rgba(201, 169, 110, 0.5);
  z-index: 10;
  pointer-events: none;
  white-space: nowrap;
}

/* 控制区：位于图片底部，默认半透明，悬停变清晰 */
.controls {
  position: absolute;
  bottom: 14px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 14px;
  z-index: 6;
  opacity: 0.45;
  transition: opacity 0.25s ease;
}
.controls:hover {
  opacity: 1;
}

.btn {
  width: 40px; height: 40px;
  border-radius: 50%;
  border: 1px solid rgba(0, 212, 255, 0.4);
  background: rgba(10, 15, 31, 0.6);
  color: var(--accent-cyan);
  font-size: 17px;
  cursor: pointer;
  transition: all 0.25s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}
.btn:hover {
  background: rgba(0, 212, 255, 0.15);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.4);
  transform: scale(1.08);
}

@media (max-width: 640px) {
  /* 小屏时舞台改为自适应（否则固定宽度会溢出） */
  .stage { width: 100%; height: auto; aspect-ratio: 4 / 3; }
  .slide img { padding: 12px; }
  .btn { width: 36px; height: 36px; font-size: 15px; }
}

/* ========================================
   教师专属 · 师承有道
   ======================================== */
.teacher-section {
  padding: 80px 60px;
  border-top: 1px solid var(--border-dim);
  text-align: center;
}
.teacher-section h2 {
  font-family: var(--font-title);
  font-size: 32px;
  font-weight: 700;
  color: var(--ink-light);
  letter-spacing: 4px;
}
.teacher-cards {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin-top: 40px;
  flex-wrap: wrap;
}
.teacher-cards .feature-card {
  max-width: 260px;
}
.teacher-cards .feature-card .icon {
  font-size: 32px;
}

/* ========================================
   模态框
   ======================================== */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  justify-content: center;
  align-items: center;
  z-index: 999;
}
.modal-content {
  background: var(--bg-card);
  padding: 40px;
  border-radius: 24px;
  border: 1px solid var(--border-card);
  text-align: center;
  max-width: min(360px, calc(100% - 32px)); /* 极窄屏保留两侧边距 */
  position: relative;
}
.modal-content img {
  width: 200px;
  height: 200px;
  border-radius: 12px;
  background: #fff;
  padding: 8px;
}
.modal-content p {
  color: var(--ink-muted);
  margin-top: 16px;
  font-size: 14px;
}
.modal-close {
  position: absolute;
  top: 12px;
  right: 20px;
  font-size: 28px;
  color: var(--ink-dim);
  cursor: pointer;
  transition: color 0.3s;
}
.modal-close:hover { color: var(--ink-light); }

/* ========================================
   页脚
   ======================================== */
.footer {
  padding: 30px 60px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 1px solid var(--border-dim);
  font-size: 14px;
  color: var(--ink-dim);
  flex-wrap: wrap;
  gap: 12px;
}

.cultural-note {
  width: 100%;
  text-align: center;
  font-size: 11px;
  color: #6B7AA8;
  letter-spacing: 1.5px;
  font-family: var(--font-body);
  padding-top: 12px;
  border-top: 1px solid rgba(42, 59, 107, 0.2);
  margin-top: 12px;
}
.wechat-link {
  background: none;
  border: none;
  color: var(--accent-gold);
  cursor: pointer;
  text-decoration: underline;
  font-size: 14px;
  font-family: var(--font-body);
  transition: color 0.3s;
}
.wechat-link:hover { color: var(--parchment); }

/* ========================================
   响应式适配
   ======================================== */
@media (max-width: 768px) {
  .navbar { padding: 12px 20px; flex-wrap: wrap; gap: 8px; }
  .logo-epoch { padding-left: 30px; }
  .nav-links { order: 3; width: 100%; display: flex; justify-content: center; gap: 4px; }
  .nav-links a { margin: 0 8px; font-size: 13px; }
  .feedback-btn { display: none; }

  .hero-content h1 { font-size: 34px; letter-spacing: 4px; }
  .ancient-quote { font-size: 12px; }
  .hero-content .subtitle { font-size: 15px; }

  .features { padding: 60px 20px; }
  .features .feature-card { max-width: 100%; }

  .video-section { padding: 60px 20px; }
  .video-section h2 { font-size: 22px; }

  .teacher-section { padding: 60px 20px; }
  .footer { padding: 20px; flex-direction: column; gap: 12px; text-align: center; }
}

@media (max-width: 480px) {
  .hero-content h1 { font-size: 28px; }
  .btn-primary, .btn-ghost { padding: 12px 28px; font-size: 14px; }
  .logo-title { font-size: 18px; }
  .logo-subtitle { font-size: 13px; }
  .modal-content { padding: 28px 20px; }
}


/* ========================================
   权威背书 · 信任区
   ======================================== */
.trust-section {
  padding: 80px 60px;
  border-top: 1px solid var(--border-dim);
  text-align: center;
}
.trust-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 48px;
  margin-top: 32px;
}
.trust-item {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 16px;
  padding: 28px 36px;
  min-width: 240px;
}
.rating-stars {
  color: var(--accent-gold);
  font-size: 28px;
  letter-spacing: 4px;
}
.rating-text {
  color: var(--ink-muted);
  font-size: 16px;
  margin-top: 8px;
}
.rating-text strong {
  color: var(--accent-cyan);
  font-weight: 700;
}
.logo-wall {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px 28px;
}
.school-logo {
  color: var(--ink-muted);
  font-size: 15px;
  font-weight: 500;
  background: rgba(201, 168, 76, 0.06);
  padding: 6px 16px;
  border-radius: 30px;
  border: 1px solid rgba(201, 168, 76, 0.1);
}
.trust-sub {
  margin-top: 14px;
  color: var(--ink-dim);
  font-size: 14px;
}

/* ========================================
   FAQ 折叠问答
   ======================================== */
.faq-section {
  padding: 80px 60px;
  border-top: 1px solid var(--border-dim);
}
.faq-section h2 {
  font-family: var(--font-title);
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  color: var(--ink-light);
  letter-spacing: 4px;
  margin-bottom: 40px;
}
.faq-list {
  max-width: 760px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 12px;
  overflow: hidden;
}
.faq-question {
  padding: 18px 28px;
  font-weight: 600;
  color: var(--accent-cyan);
  cursor: pointer;
  position: relative;
  user-select: none;
  transition: background 0.3s;
}
.faq-question::after {
  content: '+';
  position: absolute;
  right: 28px;
  font-size: 24px;
  color: var(--accent-gold);
  transition: transform 0.3s;
}
.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}
.faq-answer {
  padding: 0 28px 18px;
  color: var(--ink-muted);
  line-height: 1.7;
  display: none;
}
.faq-item.active .faq-answer {
  display: block;
}
.faq-question:hover {
  background: rgba(0, 212, 255, 0.04);
}

/* ========================================
   响应式补充
   ======================================== */
@media (max-width: 768px) {
  .trust-section { padding: 60px 20px; }
  .trust-grid { flex-direction: column; align-items: center; gap: 24px; }
  .faq-section { padding: 60px 20px; }
  .faq-section h2 { font-size: 22px; }
  .faq-question { font-size: 15px; padding: 14px 20px; }
  .faq-answer { font-size: 14px; padding: 0 20px 14px; }
}