/* ==========================================================================
   魔戒机场 · 方案 C (暗夜银环 · 星际双界) 独立样式表
   项目代号: MRA-SILVER-C03
   设计原则: 双界分屏 / 横向展廊 / 焦点转化 / 极致留白 / 高科技克制写实质感
   ========================================================================== */

:root {
  --color-obsidian: #05080E;
  --color-space-deep: #0B1422;
  --color-space-card: #0E1829;
  --color-silver: #E8F0F7;
  --color-silver-dim: #C5D4E3;
  --color-ice-blue: #91DDF5;
  --color-text-muted: #AAB8CA;
  --border-silver: rgba(232, 240, 247, 0.16);
  --border-silver-strong: rgba(232, 240, 247, 0.32);
  --glow-ice: rgba(145, 221, 245, 0.20);
  --glow-ice-subtle: rgba(145, 221, 245, 0.08);

  --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-family-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --container-max: 1320px;
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 32px;
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  background-color: var(--color-obsidian);
  color: var(--color-silver);
  font-family: var(--font-family-base);
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  line-height: 1.65;
  background: radial-gradient(circle at 80% 20%, rgba(145, 221, 245, 0.05) 0%, transparent 60%),
              radial-gradient(circle at 20% 80%, rgba(11, 20, 34, 0.6) 0%, transparent 70%),
              var(--color-obsidian);
  min-height: 100vh;
  overflow-x: hidden;
}

/* 键盘可访问性跳过链接 */
.skip-link {
  position: absolute;
  top: -60px;
  left: 20px;
  background: var(--color-ice-blue);
  color: var(--color-obsidian);
  font-weight: 700;
  padding: 12px 24px;
  z-index: 10000;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: 20px;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* 按钮与交互控件 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  min-width: 44px;
  padding: 12px 28px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, #E8F0F7 0%, #B9D7F2 100%);
  color: #05080E;
  box-shadow: 0 4px 20px rgba(145, 221, 245, 0.25);
}
.btn-primary:hover {
  background: #FFFFFF;
  box-shadow: 0 6px 28px rgba(145, 221, 245, 0.45);
  transform: translateY(-2px);
}

.btn-secondary {
  background: rgba(232, 240, 247, 0.06);
  color: var(--color-silver);
  border-color: var(--border-silver);
  backdrop-filter: blur(8px);
}
.btn-secondary:hover {
  background: rgba(232, 240, 247, 0.12);
  border-color: var(--border-silver-strong);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.btn-sm {
  min-height: 38px;
  padding: 8px 18px;
  font-size: 0.88rem;
}

:focus-visible {
  outline: 2px solid var(--color-ice-blue);
  outline-offset: 3px;
}

/* ==========================================================================
   模块 01: 极简悬浮导航
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 999;
  width: 100%;
  background: rgba(5, 8, 14, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-silver);
  transition: all var(--transition-normal);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--color-silver);
}
.brand-link img {
  width: 36px;
  height: 36px;
  object-fit: contain;
}
.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}
.brand-badge {
  font-size: 0.68rem;
  color: var(--color-ice-blue);
  background: rgba(145, 221, 245, 0.12);
  border: 1px solid rgba(145, 221, 245, 0.25);
  padding: 2px 8px;
  border-radius: 20px;
  margin-left: 4px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 32px;
}
.site-nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 8px 0;
  position: relative;
  transition: color var(--transition-fast);
}
.site-nav a:hover,
.site-nav a.active {
  color: var(--color-silver);
}
.site-nav a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--color-ice-blue);
  transition: width var(--transition-normal);
}
.site-nav a:hover::after,
.site-nav a.active::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-silver);
  color: var(--color-silver);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

/* ==========================================================================
   模块 02: 左右双世界 Hero (46% vs 54%)
   ========================================================================== */
.hero-dual-world {
  position: relative;
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: center;
  padding: 60px 0 80px;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 46% 54%;
  align-items: center;
  gap: 40px;
  width: 100%;
}

.hero-text-world {
  display: flex;
  flex-direction: column;
  justify-content: center;
  z-index: 2;
}

.hero-series-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-ice-blue);
  background: rgba(145, 221, 245, 0.08);
  border: 1px solid rgba(145, 221, 245, 0.22);
  padding: 6px 14px;
  border-radius: 30px;
  width: fit-content;
  margin-bottom: 24px;
}
.hero-series-tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-ice-blue);
  box-shadow: 0 0 10px var(--color-ice-blue);
}

.hero-title {
  font-size: clamp(2.4rem, 4vw, 3.8rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.8px;
  color: var(--color-silver);
  margin-bottom: 20px;
}
.hero-title .title-accent {
  background: linear-gradient(135deg, #FFFFFF 20%, #91DDF5 80%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: clamp(1.05rem, 1.2vw, 1.2rem);
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 500px;
  margin-bottom: 36px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-specs-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  padding-top: 28px;
  border-top: 1px solid var(--border-silver);
}
.spec-item {
  display: flex;
  flex-direction: column;
}
.spec-val {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-silver);
}
.spec-label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* Hero 右侧沉浸视觉世界 */
.hero-visual-world {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}

.visual-canvas-card {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 11;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-silver);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.7), 0 0 40px var(--glow-ice-subtle);
  background: var(--color-space-deep);
}
.visual-canvas-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s ease;
}
.visual-canvas-card:hover img {
  transform: scale(1.03);
}

.visual-tag-overlay {
  position: absolute;
  bottom: 16px;
  right: 16px;
  background: rgba(5, 8, 14, 0.75);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-silver);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: var(--color-silver-dim);
}

/* ==========================================================================
   模块 03: 横向核心优势画廊
   ========================================================================== */
.section-features {
  padding: 100px 0;
  background: linear-gradient(180deg, var(--color-obsidian) 0%, #080E18 100%);
  border-top: 1px solid var(--border-silver);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 48px;
}
.head-left {
  max-width: 600px;
}
.section-subtitle {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-ice-blue);
  margin-bottom: 8px;
}
.section-title {
  font-size: clamp(1.8rem, 2.5vw, 2.4rem);
  font-weight: 700;
  color: var(--color-silver);
  margin-bottom: 12px;
}
.section-desc {
  font-size: 1rem;
  color: var(--color-text-muted);
}

.gallery-nav-buttons {
  display: flex;
  gap: 12px;
}
.btn-nav-arrow {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(232, 240, 247, 0.06);
  border: 1px solid var(--border-silver);
  color: var(--color-silver);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all var(--transition-fast);
}
.btn-nav-arrow:hover {
  background: rgba(145, 221, 245, 0.15);
  border-color: var(--color-ice-blue);
  color: #FFFFFF;
}

.gallery-track {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  padding-bottom: 24px;
  -ms-overflow-style: none;
  scrollbar-width: none;
}
.gallery-track::-webkit-scrollbar {
  display: none;
}

.gallery-card {
  flex: 0 0 calc(50% - 12px);
  min-width: 380px;
  scroll-snap-align: start;
  background: var(--color-space-card);
  border: 1px solid var(--border-silver);
  border-radius: var(--radius-lg);
  padding: 36px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 320px;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}
.gallery-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: transparent;
  transition: background var(--transition-normal);
}
.gallery-card:hover {
  border-color: rgba(145, 221, 245, 0.4);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
}
.gallery-card:hover::before {
  background: var(--color-ice-blue);
}

.card-num {
  font-family: var(--font-family-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: rgba(145, 221, 245, 0.4);
  margin-bottom: 16px;
}
.card-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--color-silver);
  margin-bottom: 12px;
}
.card-content {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ==========================================================================
   模块 04: 中央设备舞台
   ========================================================================== */
.section-stage {
  padding: 100px 0;
  background: radial-gradient(circle at 50% 30%, rgba(145, 221, 245, 0.08) 0%, transparent 65%),
              var(--color-obsidian);
  text-align: center;
}

.stage-head {
  max-width: 720px;
  margin: 0 auto 48px;
}

.device-stage-wrapper {
  position: relative;
  max-width: 960px;
  margin: 0 auto;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--border-silver);
  background: linear-gradient(180deg, #0A121F 0%, #05080E 100%);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.8), 0 0 50px rgba(145, 221, 245, 0.12);
}
.device-stage-wrapper img {
  width: 100%;
  height: auto;
  display: block;
}

.os-support-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 36px;
  margin-top: 48px;
  padding: 20px;
  background: rgba(11, 20, 34, 0.6);
  border: 1px solid var(--border-silver);
  border-radius: 40px;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
}
.os-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--color-silver);
}
.os-item img {
  width: 22px;
  height: 22px;
}

/* ==========================================================================
   模块 05: 平台支持光带
   ========================================================================== */
.section-platforms {
  padding: 60px 0 80px;
  background: var(--color-obsidian);
  border-bottom: 1px solid var(--border-silver);
}
.platforms-wrapper {
  text-align: center;
}
.platforms-tag {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.platform-ribbon {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 16px;
}
.platform-pill {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 24px;
  background: rgba(14, 24, 41, 0.7);
  border: 1px solid var(--border-silver);
  border-radius: 30px;
  transition: all var(--transition-fast);
}
.platform-pill:hover {
  background: rgba(14, 24, 41, 1);
  border-color: rgba(145, 221, 245, 0.4);
}
.platform-pill img {
  height: 24px;
  width: auto;
  object-fit: contain;
}
.platform-pill span {
  font-size: 0.8rem;
  color: var(--color-ice-blue);
  background: rgba(145, 221, 245, 0.1);
  padding: 2px 6px;
  border-radius: 4px;
}

.platform-disclaimer {
  font-size: 0.78rem;
  color: #6C7D93;
}

/* ==========================================================================
   模块 06: 焦点套餐选择 (中央焦点 + 左右切换)
   ========================================================================== */
.section-packages {
  padding: 100px 0;
  background: radial-gradient(circle at 50% 40%, rgba(11, 20, 34, 0.8) 0%, var(--color-obsidian) 70%);
}

.focal-pricing-container {
  max-width: 840px;
  margin: 0 auto;
}

.pricing-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 36px;
}
.tab-btn {
  background: rgba(232, 240, 247, 0.05);
  border: 1px solid var(--border-silver);
  color: var(--color-text-muted);
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.tab-btn:hover {
  color: var(--color-silver);
  border-color: var(--border-silver-strong);
}
.tab-btn.active {
  background: var(--color-ice-blue);
  color: var(--color-obsidian);
  border-color: var(--color-ice-blue);
  box-shadow: 0 0 20px rgba(145, 221, 245, 0.3);
}

.focal-card-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
}

.focal-card {
  width: 100%;
  max-width: 640px;
  background: linear-gradient(165deg, #101B2E 0%, #070B13 100%);
  border: 1px solid rgba(145, 221, 245, 0.35);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.7), 0 0 40px rgba(145, 221, 245, 0.15);
  border-radius: var(--radius-xl);
  padding: 48px;
  position: relative;
  transition: all var(--transition-normal);
}

.focal-badge {
  position: absolute;
  top: 24px;
  right: 28px;
  background: rgba(145, 221, 245, 0.15);
  border: 1px solid var(--color-ice-blue);
  color: var(--color-ice-blue);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
}

.focal-pkg-name {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--color-silver);
  margin-bottom: 8px;
}

.focal-price-box {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin-bottom: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-silver);
}
.price-currency {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--color-silver);
}
.price-amount {
  font-size: 3.4rem;
  font-weight: 800;
  color: #FFFFFF;
  line-height: 1;
}
.price-period {
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

.focal-specs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 28px;
}
.spec-box {
  background: rgba(5, 8, 14, 0.6);
  border: 1px solid var(--border-silver);
  padding: 14px 18px;
  border-radius: var(--radius-md);
}
.spec-box .title {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}
.spec-box .val {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-silver);
}

.focal-features-list {
  list-style: none;
  margin-bottom: 36px;
}
.focal-features-list li {
  position: relative;
  padding-left: 26px;
  font-size: 0.95rem;
  color: var(--color-silver-dim);
  margin-bottom: 12px;
  line-height: 1.5;
}
.focal-features-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-ice-blue);
  font-weight: 800;
}

.focal-cta-btn {
  width: 100%;
  font-size: 1.1rem;
  padding: 16px;
}

.focal-notice {
  margin-top: 18px;
  font-size: 0.75rem;
  color: #6C7D93;
  text-align: center;
}

/* ==========================================================================
   模块 07: 三步使用流程 (左右交错立体数字轴)
   ========================================================================== */
.section-steps {
  padding: 100px 0;
  background: linear-gradient(180deg, var(--color-obsidian) 0%, #0A111E 100%);
  border-top: 1px solid var(--border-silver);
}

.timeline-wrapper {
  max-width: 860px;
  margin: 48px auto 0;
  position: relative;
}
.timeline-wrapper::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: linear-gradient(180deg, transparent 0%, var(--border-silver-strong) 20%, var(--border-silver-strong) 80%, transparent 100%);
  transform: translateX(-50%);
}

.timeline-step {
  display: flex;
  align-items: center;
  position: relative;
  margin-bottom: 56px;
  width: 100%;
}
.timeline-step:nth-child(even) {
  flex-direction: row-reverse;
}

.step-card {
  width: calc(50% - 40px);
  background: var(--color-space-card);
  border: 1px solid var(--border-silver);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}
.step-num-bubble {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--color-space-deep);
  border: 2px solid var(--color-ice-blue);
  color: var(--color-silver);
  font-family: var(--font-family-mono);
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 16px rgba(145, 221, 245, 0.3);
  z-index: 2;
}
.step-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-silver);
  margin-bottom: 8px;
}
.step-desc {
  font-size: 0.92rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   模块 08: 用户评价与真实反馈轨道
   ========================================================================== */
.section-reviews {
  padding: 100px 0;
  background: var(--color-obsidian);
  border-top: 1px solid var(--border-silver);
}
.reviews-track {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  padding-bottom: 24px;
  -ms-overflow-style: none;
  scrollbar-width: none;
}
.reviews-track::-webkit-scrollbar {
  display: none;
}
.review-card {
  flex: 0 0 calc(33.333% - 16px);
  min-width: 340px;
  scroll-snap-align: start;
  background: var(--color-space-card);
  border: 1px solid var(--border-silver);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 280px;
  transition: all var(--transition-normal);
  position: relative;
}
.review-card:hover {
  border-color: rgba(145, 221, 245, 0.4);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
}
.review-tag-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.review-user-type {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-ice-blue);
  background: rgba(145, 221, 245, 0.1);
  border: 1px solid rgba(145, 221, 245, 0.2);
  padding: 3px 10px;
  border-radius: 20px;
}
.review-badge {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}
.review-quote {
  font-size: 0.95rem;
  color: #D3DFEB;
  line-height: 1.7;
  margin-bottom: 20px;
  font-style: normal;
}
.review-footer {
  padding-top: 16px;
  border-top: 1px solid rgba(232, 240, 247, 0.08);
  font-size: 0.78rem;
  color: #6C7D93;
}

/* ==========================================================================
   模块 09: 极简宽幅 FAQ (原生 details/summary)
   ========================================================================== */
.section-faq {
  padding: 100px 0;
  background: #080E17;
  border-top: 1px solid var(--border-silver);
}
.faq-list {
  max-width: 880px;
  margin: 48px auto 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.faq-item {
  background: var(--color-space-card);
  border: 1px solid var(--border-silver);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-fast);
}
.faq-item[open] {
  border-color: rgba(145, 221, 245, 0.4);
  background: #111D30;
}
.faq-question {
  padding: 22px 28px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-silver);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}
.faq-question::-webkit-details-marker {
  display: none;
}
.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--color-ice-blue);
  transition: transform var(--transition-fast);
}
.faq-item[open] .faq-question::after {
  content: "−";
  transform: rotate(180deg);
}
.faq-answer {
  padding: 0 28px 24px;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ==========================================================================
   模块 10: 地球双界终章 (左右分屏)
   ========================================================================== */
.section-finale {
  position: relative;
  padding: 120px 0;
  background: linear-gradient(180deg, #080E17 0%, var(--color-obsidian) 100%);
  border-top: 1px solid var(--border-silver);
  overflow: hidden;
}
.finale-grid {
  display: grid;
  grid-template-columns: 50% 50%;
  align-items: center;
  gap: 48px;
}
.finale-text {
  z-index: 2;
}
.finale-title {
  font-size: clamp(2rem, 3.2vw, 3rem);
  font-weight: 800;
  color: var(--color-silver);
  line-height: 1.2;
  margin-bottom: 20px;
}
.finale-desc {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  max-width: 480px;
}
.finale-visual {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--border-silver);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.7);
}
.finale-visual img {
  width: 100%;
  height: auto;
  display: block;
}

/* ==========================================================================
   模块 11: 极简页脚 (4 个主要入口)
   ========================================================================== */
.site-footer {
  padding: 60px 0 40px;
  background: var(--color-obsidian);
  border-top: 1px solid var(--border-silver);
  color: var(--color-text-muted);
}
.footer-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
  text-align: center;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}
.footer-brand img {
  width: 28px;
  height: 28px;
}
.footer-brand span {
  color: var(--color-silver);
  font-weight: 700;
}
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 36px;
}
.footer-nav a {
  color: var(--color-silver-dim);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}
.footer-nav a:hover {
  color: var(--color-ice-blue);
}
.footer-copy {
  font-size: 0.8rem;
  color: #6C7D93;
}

/* ==========================================================================
   响应式设计规范 (1440, 1024, 768, 390, 360)
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-visual-world {
    order: -1;
    max-width: 600px;
    margin: 0 auto;
  }
  .finale-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .guidance-grid {
    grid-template-columns: 1fr;
  }
  .gallery-card {
    flex: 0 0 80%;
    min-width: 320px;
  }
  .review-card {
    flex: 0 0 65%;
    min-width: 300px;
  }
}

@media (max-width: 768px) {
  .site-nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(5, 8, 14, 0.98);
    flex-direction: column;
    padding: 32px 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border-silver);
    display: none;
  }
  .site-nav.open {
    display: flex;
  }
  .mobile-toggle {
    display: block;
  }
  .header-cta {
    display: none;
  }
  .timeline-wrapper::before {
    left: 20px;
  }
  .timeline-step {
    flex-direction: column !important;
    align-items: flex-start;
    padding-left: 50px;
  }
  .step-num-bubble {
    left: 20px;
  }
  .step-card {
    width: 100%;
  }
  .focal-specs-grid {
    grid-template-columns: 1fr;
  }
  .focal-card {
    padding: 32px 20px;
  }
  .os-support-bar {
    gap: 20px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }
  .hero-cta-group .btn {
    width: 100%;
  }
  .gallery-card {
    flex: 0 0 92%;
    min-width: 280px;
    padding: 24px;
  }
  .review-card {
    flex: 0 0 92%;
    min-width: 280px;
    padding: 24px;
  }
  .footer-nav {
    gap: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}