/* ── S1: HERO BANNER ── */
#banner {
  position: relative;
  background: url('/asset/pages/index/img/banner.png') center/cover no-repeat;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
}

/* 分层渐变遮罩：边缘压暗+中央透气+底部融入背景 */
#banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 70% at 50% 45%,
      rgba(0,0,0,0.25) 0%,
      rgba(0,0,0,0.65) 100%
    ),
    linear-gradient(to bottom,
      rgba(0,0,0,0.55) 0%,
      rgba(0,0,0,0.20) 35%,
      rgba(0,0,0,0.35) 65%,
      rgba(0,0,0,0.90) 100%
    );
}

/* 底部淡出，无缝接续 stats bar */
#banner::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 160px;
  background: linear-gradient(to bottom, transparent, var(--bg-primary));
  pointer-events: none;
  z-index: 1;
}

#banner > * { position: relative; z-index: 2; }

#banner .banner-content {
  max-width: 800px;
  padding: 0 var(--container-pad);
}

/* 小标签：品牌来源信息 */
#banner .banner-pretitle {
  font-size: 11px;
  letter-spacing: .4em;
  text-transform: uppercase;
  color: var(--accent-gold);
  font-family: var(--font-sans);
  margin: 0 0 var(--space-md);
  opacity: 0.9;
}

/* 主标题 */
#banner h1 {
  font-family: var(--font-serif);
  font-size: clamp(34px, 6vw, 70px);
  font-weight: 400;
  color: #fff;
  margin: 0 0 var(--space-md);
  line-height: 1.2;
  letter-spacing: .03em;
  text-shadow: 0 2px 32px rgba(0,0,0,0.6), 0 0 80px rgba(0,0,0,0.3);
}

/* 分隔装饰：细线 ◆ 细线 */
#banner .banner-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin: 0 0 var(--space-md);
}
#banner .banner-divider .bd-line {
  display: block;
  width: 100px;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--accent-gold) 60%, transparent);
}
#banner .banner-divider .bd-line:last-child {
  background: linear-gradient(to left, transparent, var(--accent-gold) 60%, transparent);
}
#banner .banner-divider .bd-diamond {
  display: block;
  width: 6px;
  height: 6px;
  background: var(--accent-gold);
  transform: rotate(45deg);
  flex-shrink: 0;
}

/* 副标题 */
#banner .banner-sub {
  font-size: clamp(12px, 1.6vw, 14px);
  color: rgba(255,255,255,0.6);
  margin: 0 0 var(--space-xl);
  letter-spacing: .28em;
  text-transform: uppercase;
  font-family: var(--font-sans);
}

#banner .banner-btns {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* 向下滚动指示器 */
#banner .banner-scroll {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  width: 26px;
  height: 40px;
  border: 1.5px solid rgba(255,255,255,0.3);
  border-radius: 13px;
  z-index: 2;
}
#banner .banner-scroll::after {
  content: '';
  display: block;
  width: 4px;
  height: 8px;
  background: rgba(255,255,255,0.6);
  border-radius: 2px;
  margin: 6px auto 0;
  animation: scroll-dot 2s ease-in-out infinite;
}
@keyframes scroll-dot {
  0%   { opacity: 1;   transform: translateY(0); }
  60%  { opacity: 0.2; transform: translateY(14px); }
  100% { opacity: 0;   transform: translateY(14px); }
}

/* ── S2: STATS BAR (reused from components) ── */

/* ── 数字滚轮动画 ── */
.stat-reel-wrap {
  display: inline-block;
  overflow: hidden;
  height: 1em;
  line-height: 1;
  vertical-align: bottom;
}
.stat-reel {
  display: flex;
  flex-direction: column;
  line-height: 1;
  will-change: transform;
}
.stat-reel span {
  display: block;
  line-height: 1;
}

/* ── S2B: BRAND STORY ── */
#index-brand-story {
  padding: var(--space-xxl) 0;
}

.brand-story-grid {
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: var(--space-xl);
  align-items: center;
}

.brand-story-copy p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.9;
  margin: 0 0 var(--space-md);
}

.brand-story-copy p:last-child {
  margin-bottom: 0;
}

.brand-story-media img {
  width: 100%;
  border-radius: var(--radius-md);
  display: block;
}

@media (max-width: 780px) {
  .brand-story-grid { grid-template-columns: 1fr; }
}

/* ── S3: WHY GERMANY ── */
#index-why {
  padding: var(--space-xxl) 0;
}
#index-why .why-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-lg);
}
@media (max-width: 600px) { #index-why .why-grid { gap: var(--space-sm); } }
.why-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  transition: var(--transition);
}
.why-card:hover { border-color: var(--border-gold); }
.why-card h3 { font-size: 17px; color: var(--text-primary); margin: 0 0 8px; }
.why-card .why-en { font-size: 14px; color: var(--accent-gold); text-transform: uppercase; letter-spacing:.1em; margin: 0 0 var(--space-sm); }
.why-card p { font-size: 14px; color: var(--text-muted); margin: 0; line-height: 1.7; }

/* ── S3B: SEO FAQ ── */
#index-seo-faq {
  padding: var(--space-xxl) 0;
  background: var(--bg-secondary);
}

.seo-faq-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.seo-faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.seo-faq-item h3 {
  font-size: 16px;
  color: var(--text-primary);
  margin: 0 0 8px;
}

.seo-faq-item p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.8;
  margin: 0;
}

@media (max-width: 700px) {
  .seo-faq-grid { gap: var(--space-sm); }
}

/* ── S3C: OKER ADVANTAGES ── */
#index-advantages {
  padding: var(--space-xxl) 0;
}

.advantage-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.advantage-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.advantage-index {
  color: var(--accent-gold);
  font-family: var(--font-serif);
  font-size: 28px;
  line-height: 1;
  opacity: .45;
  margin-bottom: var(--space-sm);
}

.advantage-item h3 {
  font-size: 15px;
  color: var(--text-primary);
  margin: 0 0 8px;
}

.advantage-item p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0;
}

@media (max-width: 900px) {
  .advantage-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 560px) {
  .advantage-grid { gap: var(--space-sm); }
}

/* ── S4: FEATURED PROFESSORS ── */
#index-professors {
  padding: var(--space-xxl) 0;
  background: var(--bg-secondary);
}
.professor-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); }
@media (max-width: 900px) { .professor-strip { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 480px) { .professor-strip { grid-template-columns: repeat(2, 1fr); } }
.prof-mini {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  text-align: center;
}
.prof-mini:hover { border-color: var(--border-gold); transform: translateY(-3px); }
.prof-mini img {
  width: 100%;
  aspect-ratio: 17 / 10;
  object-fit: contain;
  display: block;
  background: var(--bg-primary);
}
.prof-mini .pm-name { font-size: 16px; color:var(--text-primary); padding:12px 14px 4px; font-weight:500; line-height:1.3; }
.prof-mini .pm-label { font-size: 14px; color:var(--text-muted); padding:0 14px 14px; }

/* ── S5: SERVICES PREVIEW ── */
#index-services { padding: var(--space-xxl) 0; }
.service-preview-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); margin-top: var(--space-lg); }
@media (max-width: 700px) { .service-preview-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-sm); } }
.sp-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  text-decoration: none;
  display: block;
}
.sp-card:hover { border-color: var(--border-gold); transform: translateY(-3px); box-shadow: var(--shadow-card); }
.sp-card img { width:100%; aspect-ratio:4/3; object-fit:cover; display:block; }
.sp-card .sp-body { padding: var(--space-md); }
.sp-card h3 { font-size: 17px; color:var(--text-primary); margin:0 0 8px; }
.sp-card p  { font-size: 14px; color:var(--text-muted); margin:0; line-height:1.6; }

/* ── S6: APPLICATION PROCESS ── */
#index-process {
  padding: var(--space-xxl) 0;
  background: var(--bg-secondary);
}
.process-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); margin-top: var(--space-lg); }
@media (max-width: 700px) { .process-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-sm); } }
.process-step {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  position: relative;
}
.process-step .step-num {
  font-family: var(--font-serif);
  font-size: 40px; color: var(--accent-gold);
  opacity: .25; line-height: 1; margin-bottom: 8px;
}
.process-step h3 { font-size: 16px; color: var(--text-primary); margin: 0 0 8px; }
.process-step p  { font-size: 14px; color: var(--text-muted); margin: 0; line-height: 1.7; }

/* ── S7: OFFERS PREVIEW ── */
#index-offers { padding: var(--space-xxl) 0; }
.offers-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-sm); margin-top: var(--space-lg); }
@media (max-width: 600px) { .offers-grid { grid-template-columns: repeat(2, 1fr); } }
.offer-card { border-radius: var(--radius-sm); overflow: hidden; transition: var(--transition); }
.offer-card:hover { transform: scale(1.02); }
.offer-card img { width:100%; display:block; }

/* ── S8: VIDEO FEATURE ── */
#index-videos {
  padding: var(--space-xxl) 0;
  background: var(--bg-secondary);
}
.video-feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); margin-top: var(--space-lg); }
@media (max-width: 768px) { .video-feature-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-sm); } }
.vf-card { background: var(--bg-card); border-radius: var(--radius-md); overflow: hidden; border: 1px solid var(--border-subtle); }
.vf-card video { width:100%; aspect-ratio:16/9; display:block; background:#000; }
.vf-card .vf-body { padding: 12px 14px; }
.vf-card .vf-teacher { font-size: 14px; color:var(--text-muted); margin:0 0 4px; }
.vf-card .vf-title  { font-size: 14px; color:var(--accent-gold); margin:0; line-height:1.4; }

/* ── S9: GERMAN PREVIEW ── */
#index-german { padding: var(--space-xxl) 0; }
.german-preview-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-md); margin-top: var(--space-lg); }
@media (max-width: 700px) { .german-preview-grid { grid-template-columns: repeat(2, 1fr); } }
.gp-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  text-decoration: none;
  display: block;
}
.gp-card:hover { border-color: var(--border-gold); transform: translateY(-2px); }
.gp-card img {
  width: 100%;
  aspect-ratio: 211 / 180;
  object-fit: contain;
  display: block;
  background: var(--bg-primary);
}
.gp-card .gp-name { padding: 12px; font-size: 15px; color:var(--text-primary); font-weight:500; }

/* ── MOBILE OVERRIDES ── */
@media (max-width: 768px) {
  /* Banner：去掉 min-height，改用 padding 撑高，消除上下大面积黑色空白 */
  #banner {
    min-height: 0;
    padding-top: 80px;
    padding-bottom: 90px;
  }

  /* 滚动指示器（在 padding 驱动高度下位置不正确，直接隐藏） */
  #banner .banner-scroll {
    display: none;
  }

  /* 装饰小标题：大字间距在小屏溢出 */
  #banner .banner-pretitle {
    letter-spacing: 0.1em;
    font-size: 10px;
  }

  #banner .banner-sub {
    letter-spacing: 0.1em;
  }

  /* Why-card：手机端 horizontal padding 缩小，避免文字挤压 */
  .why-card {
    padding: 16px 20px;
  }

  /* 手机单列 */
  #index-why .why-grid { grid-template-columns: 1fr; }
  .seo-faq-grid { grid-template-columns: 1fr; }

  /* 品牌故事网格：手机单列 */
  .brand-story-grid {
    gap: var(--space-md);
  }

  /* 教授展示：手机双列 */
  .professor-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
  }
}

@media (max-width: 480px) {
  /* 按钮在极小屏下撑满宽度 */
  #banner .banner-btns {
    flex-direction: column;
    align-items: center;
  }

  #banner .banner-btns .btn {
    width: 200px;
    text-align: center;
  }
}