@charset "UTF-8";

/* ================================================
   漫蛙2 官方单页网站 - 主样式表
   响应式断点: 320px手机 / 768px平板 / 1200px桌面
   ================================================ */

/* ---------- CSS 变量（设计令牌） ---------- */
:root {
  --color-bg-primary: #1a1a2e;
  --color-bg-secondary: #16213e;
  --color-bg-card: #faf3e0;
  --color-bg-card-alt: #f5eddc;
  --color-bg-footer: #0f0f23;

  --color-accent-red: #e63946;
  --color-accent-red-hover: #c1121f;
  --color-accent-orange: #f4a261;
  --color-accent-orange-hover: #e07b20;
  --color-accent-blue: #457b9d;
  --color-accent-purple: #6c5ce7;

  --color-text-primary: #2d2d2d;
  --color-text-secondary: #6b7280;
  --color-text-light: #faf3e0;
  --color-text-muted: #9ca3af;

  --font-heading: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "STSong", serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;

  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 48px;
  --spacing-xl: 80px;
  --spacing-xxl: 120px;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.16);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.1);

  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;

  --max-width: 1200px;
  --nav-height: 72px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 全局清除a标签移动端点击时白色透明高亮过渡动画 */
a {
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  text-decoration: none;
  color: inherit;
}

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

ul {
  list-style: none;
}

/* ---------- 滚动进入淡入动画 ---------- */
.fade-in-up {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 延迟淡入 */
.fade-in-up[data-delay="1"] { transition-delay: 0.15s; }
.fade-in-up[data-delay="2"] { transition-delay: 0.3s; }
.fade-in-up[data-delay="3"] { transition-delay: 0.45s; }
.fade-in-up[data-delay="4"] { transition-delay: 0.6s; }
.fade-in-up[data-delay="5"] { transition-delay: 0.75s; }
.fade-in-up[data-delay="6"] { transition-delay: 0.9s; }

/* ---------- 通用容器 ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* 板块通用样式 */
.section {
  padding: var(--spacing-xl) 0;
  position: relative;
  overflow: hidden;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.section-label {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent-red);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-xs);
  padding: 4px 16px;
  border: 1px solid rgba(230, 57, 70, 0.3);
  border-radius: var(--radius-full);
  background: rgba(230, 57, 70, 0.06);
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
  line-height: 1.3;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* ================================================
   导航栏
   ================================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(26, 26, 46, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: background var(--transition-normal), box-shadow var(--transition-normal);
}

.navbar.scrolled {
  background: rgba(26, 26, 46, 0.95);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.navbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-light);
  z-index: 1001;
  transition: opacity var(--transition-fast);
}

.navbar-logo:hover {
  opacity: 0.85;
}

.navbar-logo img {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
}

/* 桌面端导航菜单 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-menu li a {
  display: block;
  padding: 8px 16px;
  font-size: 0.95rem;
  font-weight: 500;
  color: rgba(250, 243, 224, 0.75);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-menu li a:hover,
.nav-menu li a:active {
  color: var(--color-accent-red);
  background: rgba(230, 57, 70, 0.08);
}

/* 手机端菜单按钮 */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 1001;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}

.nav-toggle:hover {
  background: rgba(255, 255, 255, 0.08);
}

.nav-toggle i {
  display: block;
  width: 24px;
  height: 24px;
  background: url("../icons/menu.svg") center / contain no-repeat;
}

.nav-toggle.active i {
  background-image: url("../icons/close.svg");
}

/* 移动端菜单覆盖层 */
.nav-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.nav-overlay.active {
  display: block;
  opacity: 1;
}

/* ================================================
   主视觉区 Hero
   ================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background-color: var(--color-bg-primary);
  background-image: url("../images/hero-bg.svg");
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  overflow: hidden;
}

/* Hero 装饰元素 */
.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background:
    radial-gradient(circle at 30% 40%, rgba(230, 57, 70, 0.06) 0%, transparent 50%),
    radial-gradient(circle at 70% 60%, rgba(108, 92, 231, 0.06) 0%, transparent 50%),
    radial-gradient(circle at 50% 30%, rgba(244, 162, 97, 0.04) 0%, transparent 50%);
  animation: heroBgPulse 12s ease-in-out infinite;
  pointer-events: none;
}

@keyframes heroBgPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.05); opacity: 0.8; }
}

/* 速度线装饰 */
.hero-speed-lines {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  overflow: hidden;
  z-index: 1;
}

.hero-speed-lines span {
  position: absolute;
  display: block;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(230, 57, 70, 0.2), transparent);
  animation: speedLine 6s linear infinite;
}

.hero-speed-lines span:nth-child(1) { top: 15%; left: -100%; width: 60%; animation-delay: 0s; }
.hero-speed-lines span:nth-child(2) { top: 35%; left: -100%; width: 40%; animation-delay: 1.5s; }
.hero-speed-lines span:nth-child(3) { top: 55%; left: -100%; width: 70%; animation-delay: 3s; }
.hero-speed-lines span:nth-child(4) { top: 75%; left: -100%; width: 50%; animation-delay: 4.5s; }

@keyframes speedLine {
  0% { transform: translateX(0); opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  100% { transform: translateX(300%); opacity: 0; }
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
  padding: 0 var(--spacing-md);
}

/* 对话气泡标签 */
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(230, 57, 70, 0.12);
  border: 1px solid rgba(230, 57, 70, 0.3);
  border-radius: var(--radius-full);
  padding: 6px 20px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent-red);
  margin-bottom: var(--spacing-md);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

.hero-badge i {
  display: inline-block;
  width: 16px;
  height: 16px;
  background: url("../icons/star.svg") center / contain no-repeat;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: 4rem;
  font-weight: 800;
  color: var(--color-text-light);
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  text-shadow: 0 0 60px rgba(230, 57, 70, 0.3);
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--color-accent-red), var(--color-accent-orange));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: rgba(250, 243, 224, 0.7);
  margin-bottom: var(--spacing-lg);
  line-height: 1.8;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent-red), #d62839);
  color: #fff;
  box-shadow: 0 4px 20px rgba(230, 57, 70, 0.4);
}

.btn-primary:hover {
  box-shadow: 0 6px 28px rgba(230, 57, 70, 0.55);
  background: linear-gradient(135deg, var(--color-accent-red-hover), #b10f1f);
}

.btn-outline {
  background: transparent;
  color: var(--color-text-light);
  border: 2px solid rgba(250, 243, 224, 0.3);
}

.btn-outline:hover {
  border-color: var(--color-accent-red);
  color: var(--color-accent-red);
  background: rgba(230, 57, 70, 0.06);
}

.btn i {
  display: inline-block;
  width: 20px;
  height: 20px;
}

.btn i.icon-download {
  background: url("../icons/download.svg") center / contain no-repeat;
}

.btn i.icon-arrow {
  background: url("../icons/arrow-right.svg") center / contain no-repeat;
}

/* 滚动指示器 */
.hero-scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: bounce 2s ease-in-out infinite;
}

.hero-scroll-indicator span {
  font-size: 0.75rem;
  color: rgba(250, 243, 224, 0.5);
  letter-spacing: 2px;
  text-transform: uppercase;
}

.hero-scroll-indicator i {
  display: block;
  width: 24px;
  height: 24px;
  background: url("../icons/chevron-right.svg") center / contain no-repeat;
  transform: rotate(90deg);
  opacity: 0.5;
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(10px); }
}

/* ================================================
   功能亮点 Features
   ================================================ */
.features {
  background-color: var(--color-bg-secondary);
  position: relative;
}

/* 漫画网点纹理 */
.features::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    radial-gradient(circle, rgba(250, 243, 224, 0.03) 0.5px, transparent 0.5px);
  background-size: 20px 20px;
  pointer-events: none;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
  position: relative;
  z-index: 1;
}

.feature-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg) var(--spacing-md);
  text-align: center;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
  cursor: default;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent-red), transparent);
  transition: width var(--transition-slow);
}

.feature-card:hover::before {
  width: 80%;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(230, 57, 70, 0.2);
}

.feature-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--spacing-md);
  background: rgba(230, 57, 70, 0.08);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-normal), transform var(--transition-normal);
}

.feature-card:hover .feature-icon {
  background: rgba(230, 57, 70, 0.15);
  transform: scale(1.1);
}

.feature-icon i {
  display: block;
  width: 32px;
  height: 32px;
}

.feature-icon .icon-speed {
  background: url("../icons/speed.svg") center / contain no-repeat;
}

.feature-icon .icon-library {
  background: url("../icons/library.svg") center / contain no-repeat;
}

.feature-icon .icon-night {
  background: url("../icons/night.svg") center / contain no-repeat;
}

.feature-icon .icon-sync {
  background: url("../icons/sync.svg") center / contain no-repeat;
}

.feature-icon .icon-star {
  background: url("../icons/star.svg") center / contain no-repeat;
}

.feature-icon .icon-personalize {
  background: url("../icons/personalize.svg") center / contain no-repeat;
}

.feature-card h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-xs);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ================================================
   界面预览 Screenshots
   ================================================ */
.screenshots {
  background-color: var(--color-bg-primary);
}

.screenshots-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.screenshot-item {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: pointer;
  border: 2px solid rgba(255, 255, 255, 0.06);
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
  aspect-ratio: 4 / 2.8;
}

.screenshot-item:hover {
  transform: scale(1.03);
  border-color: rgba(230, 57, 70, 0.4);
  box-shadow: 0 8px 32px rgba(230, 57, 70, 0.15);
}

.screenshot-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.screenshot-item:hover img {
  transform: scale(1.08);
}

/* 截图hover遮罩放大镜 */
.screenshot-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(26, 26, 46, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.screenshot-item:hover .screenshot-overlay {
  opacity: 1;
}

.screenshot-overlay i {
  display: block;
  width: 40px;
  height: 40px;
  background: url("../icons/info.svg") center / contain no-repeat;
  filter: brightness(0) invert(1);
  opacity: 0.9;
}

/* ---------- 截图预览模态框 ---------- */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.9);
  align-items: center;
  justify-content: center;
  flex-direction: column;
}

.modal.active {
  display: flex;
}

.modal-content {
  max-width: 90vw;
  max-height: 80vh;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
  position: relative;
}

.modal-content img {
  max-width: 100%;
  max-height: 80vh;
  object-fit: contain;
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 40px;
  height: 40px;
  background: rgba(0, 0, 0, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  cursor: pointer;
  z-index: 2001;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.modal-close:hover {
  background: rgba(230, 57, 70, 0.6);
  transform: rotate(90deg);
}

.modal-close i {
  display: block;
  width: 20px;
  height: 20px;
  margin: auto;
  background: url("../icons/close.svg") center / contain no-repeat;
}

.modal-nav {
  display: flex;
  gap: 16px;
  margin-top: var(--spacing-md);
}

.modal-nav button {
  width: 48px;
  height: 48px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 50%;
  cursor: pointer;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.modal-nav button:hover {
  background: rgba(230, 57, 70, 0.3);
  transform: scale(1.1);
}

.modal-nav button i {
  display: block;
  width: 20px;
  height: 20px;
  margin: auto;
  background: url("../icons/arrow-right.svg") center / contain no-repeat;
  filter: brightness(0) invert(1);
}

.modal-nav .modal-prev i {
  transform: rotate(180deg);
}

/* ================================================
   版本下载 Download
   ================================================ */
.download {
  background-color: var(--color-bg-secondary);
  position: relative;
}

.download::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    linear-gradient(45deg, rgba(230, 57, 70, 0.02) 25%, transparent 25%),
    linear-gradient(-45deg, rgba(230, 57, 70, 0.02) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, rgba(230, 57, 70, 0.02) 75%),
    linear-gradient(-45deg, transparent 75%, rgba(230, 57, 70, 0.02) 75%);
  background-size: 40px 40px;
  pointer-events: none;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-md);
  position: relative;
  z-index: 1;
}

.download-card {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg) var(--spacing-md);
  text-align: center;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
}

.download-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.download-card.windows:hover { border-color: rgba(69, 123, 157, 0.4); }
.download-card.macos:hover { border-color: rgba(244, 162, 97, 0.4); }
.download-card.android:hover { border-color: rgba(108, 92, 231, 0.4); }
.download-card.ios:hover { border-color: rgba(230, 57, 70, 0.4); }

.download-card-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto var(--spacing-md);
  background: rgba(255, 255, 255, 0.06);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-normal);
}

.download-card:hover .download-card-icon {
  background: rgba(230, 57, 70, 0.12);
}

.download-card-icon i {
  display: block;
  width: 28px;
  height: 28px;
}

.download-card-icon .icon-windows {
  background: url("../icons/windows.svg") center / contain no-repeat;
}

.download-card-icon .icon-apple {
  background: url("../icons/apple.svg") center / contain no-repeat;
}

.download-card-icon .icon-android {
  background: url("../icons/android.svg") center / contain no-repeat;
}

.download-card-icon .icon-ios {
  background: url("../icons/ios.svg") center / contain no-repeat;
}

.download-card h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-light);
  margin-bottom: 4px;
}

.download-card .version {
  font-size: 0.85rem;
  color: var(--color-accent-red);
  margin-bottom: 4px;
}

.download-card .size {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-md);
}

.download-card .btn-download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  background: var(--color-accent-red);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.download-card .btn-download:hover {
  background: var(--color-accent-red-hover);
  transform: scale(1.05);
}

.download-card .btn-download i {
  display: inline-block;
  width: 16px;
  height: 16px;
  background: url("../icons/download.svg") center / contain no-repeat;
  filter: brightness(0) invert(1);
}

/* ================================================
   更新日志 Changelog
   ================================================ */
.changelog {
  background-color: var(--color-bg-primary);
}

.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 40px;
}

/* 时间轴中线 */
.timeline::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(
    to bottom,
    var(--color-accent-red),
    var(--color-accent-purple),
    var(--color-accent-blue)
  );
  border-radius: 1px;
}

.timeline-item {
  position: relative;
  margin-bottom: var(--spacing-lg);
  opacity: 0;
  transform: translateX(-20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.timeline-item.visible {
  opacity: 1;
  transform: translateX(0);
}

/* 时间轴节点 */
.timeline-item::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-accent-red);
  border: 3px solid var(--color-bg-primary);
  box-shadow: 0 0 0 3px rgba(230, 57, 70, 0.3);
  z-index: 2;
}

.timeline-item:nth-child(2)::before { background: var(--color-accent-orange); box-shadow: 0 0 0 3px rgba(244, 162, 97, 0.3); }
.timeline-item:nth-child(3)::before { background: var(--color-accent-purple); box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.3); }
.timeline-item:nth-child(4)::before { background: var(--color-accent-blue); box-shadow: 0 0 0 3px rgba(69, 123, 157, 0.3); }

.timeline-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.timeline-version {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text-light);
  background: rgba(255, 255, 255, 0.06);
  padding: 4px 16px;
  border-radius: var(--radius-full);
}

.timeline-date {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.timeline-content {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  transition: border-color var(--transition-normal);
}

.timeline-item:hover .timeline-content {
  border-color: rgba(230, 57, 70, 0.2);
}

.timeline-content ul {
  list-style: none;
}

.timeline-content ul li {
  padding: 6px 0;
  font-size: 0.95rem;
  color: var(--color-text-muted);
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.6;
}

.timeline-content ul li i {
  display: inline-block;
  width: 16px;
  height: 16px;
  min-width: 16px;
  background: url("../icons/check.svg") center / contain no-repeat;
  margin-top: 3px;
}

/* ================================================
   关于我们 About
   ================================================ */
.about {
  background-color: var(--color-bg-secondary);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
  align-items: center;
  max-width: 900px;
  margin: 0 auto;
}

.about-text h3 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-sm);
}

.about-text p {
  font-size: 1rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: var(--spacing-sm);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-md);
}

.about-stat {
  text-align: center;
  padding: var(--spacing-md);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-md);
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}

.about-stat:hover {
  transform: translateY(-4px);
  border-color: rgba(230, 57, 70, 0.2);
}

.about-stat .stat-number {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-accent-red), var(--color-accent-orange));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.about-stat .stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ================================================
   底部版权 Footer
   ================================================ */
.footer {
  background-color: var(--color-bg-footer);
  padding: var(--spacing-lg) 0 var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text-light);
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
}

.footer-links {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-accent-red);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-bottom p {
  font-size: 0.85rem;
  color: rgba(250, 243, 224, 0.4);
  line-height: 1.6;
}

/* ================================================
   返回顶部 Back to Top
   ================================================ */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  background: var(--color-accent-red);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(230, 57, 70, 0.4);
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity var(--transition-normal), transform var(--transition-normal), visibility var(--transition-normal), background var(--transition-fast);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--color-accent-red-hover);
  transform: translateY(-4px);
}

.back-to-top i {
  display: block;
  width: 20px;
  height: 20px;
  margin: auto;
  background: url("../icons/arrow-up.svg") center / contain no-repeat;
}

/* ================================================
   响应式设计 - 平板端 (768px - 1199px)
   ================================================ */
@media screen and (max-width: 1199px) {
  :root {
    --spacing-xl: 64px;
    --spacing-xxl: 80px;
  }

  .section-title {
    font-size: 2rem;
  }

  /* 导航栏 - 平板保持横向但缩小间距 */
  .nav-menu {
    gap: 0;
  }

  .nav-menu li a {
    padding: 8px 10px;
    font-size: 0.88rem;
  }

  /* Hero */
  .hero-title {
    font-size: 3rem;
  }

  .hero-subtitle {
    font-size: 1.1rem;
  }

  /* 功能亮点 - 2列 */
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 截图 - 2列 */
  .screenshots-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 下载 - 2列 */
  .download-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 关于 */
  .about-content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: var(--spacing-lg);
  }

  .about-stats {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ================================================
   响应式设计 - 手机端 (320px - 767px)
   ================================================ */
@media screen and (max-width: 767px) {
  :root {
    --spacing-xl: 48px;
    --spacing-lg: 32px;
    --spacing-md: 20px;
    --spacing-sm: 12px;
    --nav-height: 60px;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .section-desc {
    font-size: 0.95rem;
  }

  /* 导航栏 - 汉堡菜单 */
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 75%;
    max-width: 320px;
    height: 100vh;
    background: rgba(22, 33, 62, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: calc(var(--nav-height) + var(--spacing-md)) var(--spacing-md) var(--spacing-md);
    gap: 4px;
    transition: right var(--transition-slow);
    z-index: 1000;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.3);
  }

  .nav-menu.active {
    right: 0;
  }

  .nav-menu li {
    width: 100%;
  }

  .nav-menu li a {
    display: block;
    padding: 14px 16px;
    font-size: 1.05rem;
    border-radius: var(--radius-md);
    text-align: center;
  }

  .nav-toggle {
    display: block;
  }

  /* Hero */
  .hero-title {
    font-size: 2.2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
    margin: 0 auto;
  }

  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }

  .hero-badge {
    font-size: 0.8rem;
    padding: 4px 16px;
  }

  /* 功能亮点 - 1列 */
  .features-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    padding: var(--spacing-md);
  }

  /* 截图 - 1列 */
  .screenshots-grid {
    grid-template-columns: 1fr;
  }

  /* 下载 - 1列 */
  .download-grid {
    grid-template-columns: 1fr;
  }

  /* 时间轴 */
  .timeline {
    padding-left: 30px;
  }

  .timeline::before {
    left: 10px;
  }

  .timeline-item::before {
    left: -28px;
    width: 10px;
    height: 10px;
  }

  .timeline-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  /* 关于 */
  .about-stats {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-sm);
  }

  .about-stat .stat-number {
    font-size: 1.5rem;
  }

  .about-stat {
    padding: var(--spacing-sm);
  }

  /* 底部 */
  .footer-content {
    flex-direction: column;
    text-align: center;
  }

  .footer-links {
    justify-content: center;
  }

  /* 返回顶部 */
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
}

/* ================================================
   特小屏幕适配 (320px - 374px)
   ================================================ */
@media screen and (max-width: 374px) {
  .hero-title {
    font-size: 1.8rem;
  }

  .section-title {
    font-size: 1.4rem;
  }

  .container {
    padding: 0 12px;
  }
}