/* ============================================
   主题 CSS 变量系统
   ============================================ */

/* 默认主题：黑色科技风 */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: rgba(255, 255, 255, 0.05);
  --bg-card-hover: rgba(255, 255, 255, 0.1);
  --bg-nav: rgba(10, 10, 15, 0.85);
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b0;
  --text-muted: #6a6a7a;
  --accent: #00d4ff;
  --accent-glow: rgba(0, 212, 255, 0.3);
  --accent-gradient: linear-gradient(135deg, #00d4ff, #7b2ff7);
  --border-color: rgba(255, 255, 255, 0.08);
  --shadow-color: rgba(0, 0, 0, 0.5);
  --glass-bg: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow: rgba(0, 0, 0, 0.3);
  --timeline-color: rgba(0, 212, 255, 0.3);
  --badge-bg: linear-gradient(135deg, #00d4ff, #7b2ff7);
  --badge-text: #ffffff;
  --loading-bg: #0a0a0f;
  --scrollbar-track: #12121a;
  --scrollbar-thumb: #2a2a3a;
  --phone-shadow: rgba(0, 212, 255, 0.15);
  --nav-shadow: rgba(0, 0, 0, 0.5);
}

/* 白色简约风主题 */
[data-theme="light"] {
  --bg-primary: #f5f5f7;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.7);
  --bg-card-hover: rgba(255, 255, 255, 0.9);
  --bg-nav: rgba(255, 255, 255, 0.88);
  --text-primary: #1a1a2e;
  --text-secondary: #4a4a5a;
  --text-muted: #8a8a9a;
  --accent: #007aff;
  --accent-glow: rgba(0, 122, 255, 0.2);
  --accent-gradient: linear-gradient(135deg, #007aff, #5856d6);
  --border-color: rgba(0, 0, 0, 0.06);
  --shadow-color: rgba(0, 0, 0, 0.08);
  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-border: rgba(0, 0, 0, 0.08);
  --glass-shadow: rgba(0, 0, 0, 0.06);
  --timeline-color: rgba(0, 122, 255, 0.25);
  --badge-bg: linear-gradient(135deg, #007aff, #5856d6);
  --badge-text: #ffffff;
  --loading-bg: #f5f5f7;
  --scrollbar-track: #e8e8ed;
  --scrollbar-thumb: #c0c0c8;
  --phone-shadow: rgba(0, 122, 255, 0.12);
  --nav-shadow: rgba(0, 0, 0, 0.06);
}

/* 小米品牌橙主题 - 纯橙色（与主页一致） */
[data-theme="orange"] {
  --bg-primary: #ff6900;
  --bg-secondary: #ff8533;
  --bg-card: rgba(255, 255, 255, 0.15);
  --bg-card-hover: rgba(255, 255, 255, 0.25);
  --bg-nav: rgba(255, 105, 0, 0.92);
  --text-primary: #ffffff;
  --text-secondary: #ffe0cc;
  --text-muted: #ffd4b8;
  --accent: #ffffff;
  --accent-glow: rgba(255, 255, 255, 0.35);
  --accent-gradient: linear-gradient(135deg, #ffffff, #ffe0cc);
  --border-color: rgba(255, 255, 255, 0.25);
  --shadow-color: rgba(0, 0, 0, 0.2);
  --glass-bg: rgba(255, 255, 255, 0.15);
  --glass-border: rgba(255, 255, 255, 0.25);
  --glass-shadow: rgba(0, 0, 0, 0.2);
  --timeline-color: rgba(255, 255, 255, 0.35);
  --badge-bg: linear-gradient(135deg, #ffffff, #ffe0cc);
  --badge-text: #ff6900;
  --loading-bg: #ff6900;
  --scrollbar-track: #e85e00;
  --scrollbar-thumb: #ff8533;
  --phone-shadow: rgba(0, 0, 0, 0.15);
  --nav-shadow: rgba(0, 0, 0, 0.15);
}

/* ============================================
   基础重置
   ============================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial,
    sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  transition: background-color 0.4s ease, color 0.4s ease;
}

/* 粒子风车背景画布 */
.pinwheel-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* 兼容旧引用 */
.galaxy-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* 粒子开关按钮 */
.particle-toggle-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: transparent;
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.3s ease;
}

.particle-toggle-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.particle-toggle-btn.inactive {
  opacity: 0.4;
}

/* 自定义滚动条 */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

/* ============================================
   Loading 动画
   ============================================ */

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--loading-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  transition: opacity 0.6s ease, visibility 0.6s ease;
}

.loading-overlay.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 3px solid var(--border-color);
  border-top-color: var(--accent);
  animation: spin 0.8s linear infinite;
  margin-bottom: 20px;
}

.loading-text {
  color: var(--text-secondary);
  font-size: 14px;
  letter-spacing: 2px;
  animation: pulse 1.5s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

/* ============================================
   导航栏
   ============================================ */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: rgba(255, 255, 255, 0.02);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 1000;
  transition: background 0.4s ease;
}

.nav-brand {
  position: relative;
  z-index: 1;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: 0.5px;
  transition: color 0.3s ease;
}

.nav-brand:hover {
  color: var(--accent);
}

.nav-right {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-home-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  color: var(--text-primary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.3s ease;
  cursor: pointer;
}

.nav-home-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

/* 橙色主题下返回首页按钮颜色调整 */
html[data-theme="orange"] .nav-home-btn,
[data-theme="orange"] .nav-home-btn {
  background: rgba(0, 0, 0, 0.3) !important;
  border-color: rgba(0, 0, 0, 0.35) !important;
  color: rgba(255, 255, 255, 0.95) !important;
}

html[data-theme="orange"] .nav-home-btn:hover,
[data-theme="orange"] .nav-home-btn:hover {
  background: rgba(0, 0, 0, 0.45) !important;
  border-color: rgba(0, 0, 0, 0.5) !important;
  color: #ffffff !important;
}

.nav-home-btn svg {
  width: 14px;
  height: 14px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ============================================
   语言选择器
   ============================================ */

.lang-selector {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: transparent;
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

.lang-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.lang-arrow {
  transition: transform 0.3s ease;
}

.lang-selector.open .lang-arrow {
  transform: rotate(180deg);
}

.lang-card {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 180px;
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 6px;
  display: none;
  flex-direction: column;
  gap: 2px;
  z-index: 100;
  box-shadow: 0 8px 32px var(--shadow-color);
}

.lang-selector.open .lang-card {
  display: flex;
}

.lang-option {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  background: transparent;
  border: none;
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s ease;
  text-align: left;
}

.lang-option:hover {
  background: rgba(255, 255, 255, 0.1);
}

.lang-option.active {
  background: var(--accent-glow);
  color: var(--accent);
}

.lang-region {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ============================================
   主题切换器
   ============================================ */

.theme-switcher {
  display: flex;
  align-items: center;
  gap: 6px;
}

.theme-dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
}

.theme-dot:hover {
  transform: scale(1.15);
}

/* 暗色主题圆点 */
.theme-dot[data-theme="dark"] {
  background: linear-gradient(135deg, #0a0a0f, #1a1a2e);
}

/* 白色主题圆点：外圈透明，内圈纯白 */
.theme-dot[data-theme="light"] {
  background: #ffffff;
}

/* 橙色主题圆点 */
.theme-dot[data-theme="orange"] {
  background: linear-gradient(135deg, #ff6900, #ff9500);
}

/* 发光逻辑：当前主题的圆点外圈发光，其他不发光 */

/* 暗色页面时，暗色圆点发橙光 */
html[data-theme="dark"] .theme-dot[data-theme="dark"].active {
  box-shadow: 0 0 12px 2px rgba(255, 105, 0, 0.7);
}

/* 白色页面时，白色圆点发黑光 */
html[data-theme="light"] .theme-dot[data-theme="light"].active {
  box-shadow: 0 0 12px 2px rgba(0, 0, 0, 0.5);
}

/* 橙色页面时，橙色圆点发白光 */
html[data-theme="orange"] .theme-dot[data-theme="orange"].active {
  box-shadow: 0 0 12px 2px rgba(255, 255, 255, 0.7);
}

/* ============================================
   页面标题区域
   ============================================ */

.hero-section {
  padding: 120px 24px 60px;
  text-align: center;
  position: relative;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translateX(-50%);
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
  opacity: 0.5;
  animation: hero-glow 4s ease-in-out infinite;
}

@keyframes hero-glow {
  0%, 100% { opacity: 0.35; transform: translateX(-50%) scale(1); }
  50% { opacity: 0.65; transform: translateX(-50%) scale(1.1); }
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
  position: relative;
  letter-spacing: 2px;
}

.hero-subtitle {
  font-size: 16px;
  color: var(--text-muted);
  letter-spacing: 6px;
  text-transform: uppercase;
  font-weight: 300;
  position: relative;
}

.hero-divider {
  width: 60px;
  height: 3px;
  background: var(--accent-gradient);
  border-radius: 2px;
  margin: 24px auto 0;
  position: relative;
}

/* ============================================
   时间轴 + 瀑布流布局（修复版）
   ============================================ */

.timeline-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 80px;
  position: relative;
}

/* 单列时间轴容器 */
.waterfall-container {
  display: flex;
  flex-direction: column;
  gap: 32px;
  position: relative;
  padding-left: 48px;
}

/* 时间轴线 - 放在左侧 */
.waterfall-container::before {
  content: '';
  position: absolute;
  left: 14px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(
    to bottom,
    transparent,
    var(--timeline-color) 5%,
    var(--timeline-color) 95%,
    transparent
  );
  z-index: 0;
  animation: timeline-pulse 3s ease-in-out infinite;
}

@keyframes timeline-pulse {
  0%, 100% { opacity: 0.7; }
  50% { opacity: 1; }
}

/* ============================================
   时间轴节点（卡片 + 小点包装器）
   ============================================ */

.timeline-item {
  position: relative;
}

/* 左侧指引小点 - JS 动态定位在引导线上、卡片垂直居中 */
.timeline-dot {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent-gradient);
  border: 3px solid var(--bg-primary);
  box-shadow: 0 0 0 2px var(--timeline-color), 0 0 14px var(--accent-glow), 0 0 28px var(--accent-glow);
  z-index: 2;
  transition: box-shadow 0.3s ease, transform 0.3s ease;
}

.timeline-item:hover .timeline-dot {
  box-shadow: 0 0 0 2px var(--accent), 0 0 24px var(--accent-glow), 0 0 48px var(--accent-glow);
}

/* 小点脉冲动画 */
.timeline-dot::after {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 2px solid var(--accent-glow);
  animation: dot-pulse 2s ease-in-out infinite;
}

@keyframes dot-pulse {
  0%, 100% { opacity: 0.2; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(1.3); }
}

/* ============================================
   教程卡片 - 玻璃拟态
   ============================================ */

.tutorial-card {
  flex: 1;
  background: var(--glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 48px 24px;
  box-shadow: 0 8px 32px var(--glass-shadow);
  transition: opacity 0.6s ease, transform 0.6s ease, background 0.4s ease, box-shadow 0.4s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  /* 默认可见 */
  opacity: 1;
  transform: translateY(0);
}

.tutorial-card:hover {
  box-shadow: 0 8px 32px var(--glass-shadow), 0 0 20px var(--accent-glow), 0 0 40px rgba(0,0,0,0.1);
  border-color: var(--accent-glow);
}

/* 外边缘光效层 - 径向渐变 + mask 只显示边框环 */
.tutorial-card .card-glow {
  position: absolute;
  inset: -3px;
  border-radius: 19px;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: 0;
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  mask-composite: exclude;
  padding: 3px;
}

/* 滚动前初始状态（由JS添加 animate-on-scroll 类） */
.tutorial-card.animate-on-scroll {
  opacity: 0;
  transform: translateY(40px) scale(0.96);
}

.tutorial-card.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* 卡片内容层级高于光效 */
.tutorial-card > *:not(.card-glow) {
  position: relative;
  z-index: 2;
}

/* 步骤编号徽章 */
.step-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--badge-bg);
  color: var(--badge-text);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 16px;
  box-shadow: 0 4px 12px var(--accent-glow);
  position: relative;
}

/* 卡片标题 */
.card-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  transition: color 0.3s ease;
}

.tutorial-card:hover .card-title {
  color: var(--accent);
}

/* 卡片描述 - 居中显示 */
.card-description {
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-secondary);
  text-align: center;
  margin: 0;
}

/* 卡片标题 */
.card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  text-align: center;
  margin: 0;
  line-height: 1.5;
  transition: color 0.3s ease;
}

/* 卡片副标题 */
.card-subtitle {
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-secondary);
  text-align: center;
  margin: 10px 0 0;
}

/* 卡片链接包装（整卡片可点击） */
.tutorial-card-link {
  text-decoration: none;
  color: inherit;
  display: block;
  flex: 1;
}

.tutorial-card-link .tutorial-card {
  cursor: pointer;
}

/* 卡片内多链接区域 */
.card-links {
  display: flex;
  gap: 12px;
  margin-top: 14px;
  flex-wrap: wrap;
  justify-content: center;
}

.card-link-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  text-decoration: none;
  color: var(--text-secondary);
  transition: all 0.3s ease;
  flex: 1;
  min-width: 140px;
}

.card-link-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-glow);
  transform: translateY(-2px);
}

.card-link-tag {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
}

.card-link-text {
  font-size: 13px;
  line-height: 1.5;
  text-align: center;
}

/* ============================================
   手机截图占位区域
   ============================================ */

.phone-mockup {
  width: 100%;
  max-width: 220px;
  margin: 0 auto;
  aspect-ratio: 9 / 16;
  background: var(--bg-secondary);
  border-radius: 20px;
  border: 2px solid var(--border-color);
  position: relative;
  overflow: hidden;
  box-shadow: 0 8px 24px var(--phone-shadow), inset 0 0 20px rgba(0, 0, 0, 0.1);
  transition: transform 0.4s ease, box-shadow 0.4s ease;
}

.tutorial-card:hover .phone-mockup {
  transform: scale(1.02);
  box-shadow: 0 12px 32px var(--phone-shadow), inset 0 0 20px rgba(0, 0, 0, 0.1);
}

/* 手机顶部刘海 */
.phone-notch {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 22px;
  background: #000;
  border-radius: 0 0 14px 14px;
  z-index: 2;
}

.phone-notch::after {
  content: '';
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 8px;
  height: 8px;
  background: #1a1a2e;
  border-radius: 50%;
  border: 1px solid #2a2a3e;
}

/* 手机屏幕内容 - 渐变模拟 */
.phone-screen {
  position: absolute;
  inset: 0;
  border-radius: 18px;
  overflow: hidden;
}

/* 不同卡片使用不同渐变 */
.phone-screen.screen-1 {
  background: linear-gradient(160deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
}

.phone-screen.screen-2 {
  background: linear-gradient(160deg, #00d4ff 0%, #0052d4 50%, #4364f7 100%);
}

.phone-screen.screen-3 {
  background: linear-gradient(160deg, #11998e 0%, #38ef7d 50%, #a8e063 100%);
}

.phone-screen.screen-4 {
  background: linear-gradient(160deg, #fc5c7d 0%, #6a82fb 50%, #fc5c7d 100%);
}

.phone-screen.screen-5 {
  background: linear-gradient(160deg, #f7971e 0%, #ffd200 50%, #f7971e 100%);
}

.phone-screen.screen-6 {
  background: linear-gradient(160deg, #00c9ff 0%, #92fe9d 50%, #00c9ff 100%);
}

/* 屏幕内模拟 UI 元素 */
.screen-content {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 30px 16px 16px;
}

.screen-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(8px);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.screen-icon svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: #fff;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.screen-label {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.85);
  font-weight: 600;
  text-align: center;
  letter-spacing: 0.5px;
}

.screen-bars {
  display: flex;
  flex-direction: column;
  gap: 6px;
  width: 70%;
  margin-top: 14px;
}

.screen-bar {
  height: 6px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.2);
}

.screen-bar:nth-child(1) { width: 80%; }
.screen-bar:nth-child(2) { width: 60%; }
.screen-bar:nth-child(3) { width: 70%; }

/* 手机底部横条 */
.phone-home-indicator {
  position: absolute;
  bottom: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 40%;
  height: 4px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 2px;
  z-index: 2;
}

/* ============================================
   底部返回按钮
   ============================================ */

.footer-section {
  text-align: center;
  padding: 40px 24px 80px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.footer-section.visible {
  opacity: 1;
  transform: translateY(0);
}

.footer-home-btn {
  --follow-x: 0px;
  --follow-y: 0px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: var(--accent-gradient);
  color: #ffffff;
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  transform: translate(var(--follow-x), var(--follow-y));
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 4px 16px var(--accent-glow);
  letter-spacing: 0.5px;
}

.footer-home-btn:hover {
  transform: translate(var(--follow-x), var(--follow-y)) translateY(-2px);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.footer-home-btn svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.footer-coming-soon {
  margin-top: 16px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  opacity: 0.7;
  text-align: center;
}

/* 版权页脚 */
.tutorial-footer {
  position: relative;
  width: 100%;
  padding: 20px;
  text-align: center;
  z-index: 10;
  border-top: 1px solid var(--glass-border);
}

.tutorial-footer p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  opacity: 0.5;
  letter-spacing: 1px;
}

/* ============================================
   响应式布局
   ============================================ */

/* 平板适配 */
@media (max-width: 900px) {
  .waterfall-container {
    padding-left: 32px;
    gap: 28px;
  }

  .timeline-item {
    gap: 16px;
  }

  .hero-title {
    font-size: 36px;
  }

  .hero-subtitle {
    font-size: 14px;
    letter-spacing: 4px;
  }
}

/* 手机适配 */
/* ===== 移动端菜单按钮和弹出面板 ===== */
.nav-menu-toggle {
  display: none;
}

.nav-mobile-panel {
  display: none;
}

@media (max-width: 600px) {
  .waterfall-container {
    padding-left: 28px;
    gap: 24px;
  }

  .navbar {
    padding: 0 16px;
  }

  .nav-brand {
    font-size: 15px;
    white-space: nowrap;
  }

  /* 竖屏：隐藏导航栏右侧操作，显示菜单按钮 */
  .nav-right > .lang-selector,
  .nav-right > .theme-switcher,
  .nav-right > .particle-toggle-btn {
    display: none;
  }

  .nav-menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    background: transparent;
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s ease;
  }

  .nav-menu-toggle:hover,
  .nav-menu-toggle.active {
    background: var(--bg-card-hover);
  }

  /* 弹出面板 */
  .nav-mobile-panel {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    right: 16px;
    min-width: 200px;
    background: var(--bg-secondary);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 12px;
    z-index: 100;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 8px 32px var(--shadow-color);
    flex-direction: column;
    gap: 12px;
  }

  .nav-mobile-panel.open {
    display: flex;
  }

  .mobile-panel-row {
    display: flex;
    align-items: center;
    gap: 10px;
  }

  .mobile-panel-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    white-space: nowrap;
    min-width: 44px;
  }

  .mobile-panel-row .lang-btn {
    padding: 4px 8px;
    font-size: 0.75rem;
  }

  .mobile-panel-row .theme-switcher {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 3px 6px;
  }

  .mobile-panel-row .theme-dot {
    width: 18px;
    height: 18px;
  }

  .mobile-panel-row .mobile-func-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s ease;
  }

  .mobile-panel-row .mobile-func-btn:hover {
    background: var(--bg-card-hover);
  }

  .nav-home-btn span {
    display: none;
  }

  .nav-home-btn {
    padding: 8px 10px;
  }

  .hero-section {
    padding: 100px 16px 40px;
  }

  .hero-title {
    font-size: 28px;
  }

  .hero-subtitle {
    font-size: 12px;
    letter-spacing: 3px;
  }

  .timeline-section {
    padding: 20px 16px 60px;
  }

  .timeline-item {
    margin-bottom: 20px;
  }

  .tutorial-card {
    padding: 20px;
  }

  .phone-mockup {
    max-width: 180px;
  }

  .footer-section {
    padding: 30px 16px 60px;
  }

  .footer-home-btn {
    padding: 12px 24px;
    font-size: 14px;
  }
}