/* ===== 全局变量 ===== */
:root {
  --color-primary: #00d4aa;
  --color-primary-dark: #00b894;
  --color-primary-light: #55efc4;
  --color-accent: #fd79a8;
  --color-warning: #fdcb6e;
  --color-danger: #d63031;
  --color-bg: #0a0e17;
  --color-bg-secondary: #111827;
  --color-bg-card: #1a2332;
  --color-bg-card-hover: #243447;
  --color-text: #e2e8f0;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  --color-border: #2d3748;
  --color-border-light: #374151;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 20px rgba(0,212,170,0.15);
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  --font-main: "PingFang SC","Hiragino Sans GB","Microsoft YaHei","WenQuanYi Micro Hei",sans-serif;
  --font-mono: "SF Mono","Fira Code","Consolas",monospace;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --max-width: 1200px;
}

/* ===== 重置与基础 ===== */
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-main);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.75;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-primary-light); }
img { max-width: 100%; height: auto; display: block; }
ul,ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input,textarea,select { font-family: inherit; font-size: inherit; }

/* ===== 容器 ===== */
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--spacing-md); }

/* ===== 头部导航 ===== */
.site-header {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(10,14,23,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) 0;
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: var(--max-width); margin: 0 auto; padding: 0 var(--spacing-md);
}
.site-logo { font-size: 1.4rem; font-weight: 700; color: var(--color-primary); }
.site-logo span { color: var(--color-text); }
.nav-desktop { display: flex; gap: var(--spacing-lg); align-items: center; }
.nav-desktop a { color: var(--color-text-secondary); font-size: 0.95rem; font-weight: 500; padding: var(--spacing-xs) var(--spacing-sm); border-radius: var(--radius-sm); transition: all var(--transition-fast); }
.nav-desktop a:hover { color: var(--color-primary); background: rgba(0,212,170,0.08); }
.nav-mobile-toggle { display: none; width: 36px; height: 36px; flex-direction: column; justify-content: center; align-items: center; gap: 5px; }
.nav-mobile-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); border-radius: 2px; transition: all var(--transition-fast); }
.nav-mobile { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(10,14,23,0.98); z-index: 9999; flex-direction: column; align-items: center; justify-content: center; gap: var(--spacing-xl); }
.nav-mobile.active { display: flex; }
.nav-mobile a { font-size: 1.3rem; color: var(--color-text); font-weight: 600; }
.nav-mobile-close { position: absolute; top: var(--spacing-lg); right: var(--spacing-lg); font-size: 2rem; color: var(--color-text); }

/* ===== 首屏 ===== */
.hero {
  padding: var(--spacing-3xl) 0;
  text-align: center;
  background: linear-gradient(180deg, rgba(0,212,170,0.05) 0%, transparent 60%);
  position: relative;
}
.hero::before {
  content: ''; position: absolute; top: 0; left: 50%; transform: translateX(-50%);
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(0,212,170,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero h1 { font-size: clamp(1.8rem, 5vw, 3rem); font-weight: 800; margin-bottom: var(--spacing-md); position: relative; }
.hero .subtitle { font-size: clamp(1rem, 2.5vw, 1.25rem); color: var(--color-text-secondary); max-width: 700px; margin: 0 auto var(--spacing-xl); line-height: 1.8; position: relative; }
.hero-cta { display: flex; gap: var(--spacing-md); justify-content: center; flex-wrap: wrap; position: relative; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-md); font-weight: 600; font-size: 0.95rem;
  transition: all var(--transition-normal);
}
.btn-primary { background: var(--color-primary); color: var(--color-bg); }
.btn-primary:hover { background: var(--color-primary-light); color: var(--color-bg); box-shadow: var(--shadow-glow); transform: translateY(-2px); }
.btn-outline { border: 2px solid var(--color-border-light); color: var(--color-text); }
.btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn-danger { background: var(--color-danger); color: #fff; }
.btn-warning { background: var(--color-warning); color: var(--color-bg); }

/* ===== 区块标题 ===== */
.section { padding: var(--spacing-3xl) 0; }
.section-header { text-align: center; margin-bottom: var(--spacing-2xl); }
.section-header h2 { font-size: clamp(1.4rem, 3vw, 2rem); font-weight: 700; margin-bottom: var(--spacing-sm); }
.section-header p { color: var(--color-text-secondary); max-width: 600px; margin: 0 auto; }

/* ===== 卡片 ===== */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: all var(--transition-normal);
}
.card:hover { background: var(--color-bg-card-hover); border-color: var(--color-primary); box-shadow: var(--shadow-glow); transform: translateY(-3px); }
.card-icon { width: 48px; height: 48px; border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; font-size: 1.5rem; margin-bottom: var(--spacing-md); background: rgba(0,212,170,0.1); color: var(--color-primary); }
.card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: var(--spacing-sm); }
.card p { color: var(--color-text-secondary); font-size: 0.9rem; line-height: 1.7; }

/* ===== 网格布局 ===== */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--spacing-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--spacing-lg); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--spacing-lg); }

/* ===== 步骤卡片 ===== */
.steps { counter-reset: step; }
.step-item {
  position: relative; padding-left: 60px; margin-bottom: var(--spacing-xl);
  counter-increment: step;
}
.step-item::before {
  content: counter(step);
  position: absolute; left: 0; top: 0;
  width: 42px; height: 42px; border-radius: 50%;
  background: var(--color-primary); color: var(--color-bg);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.1rem;
}
.step-item h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: var(--spacing-xs); }
.step-item p { color: var(--color-text-secondary); font-size: 0.9rem; }

/* ===== 警示框 ===== */
.alert {
  padding: var(--spacing-lg);
  border-radius: var(--radius-md);
  border-left: 4px solid;
  margin-bottom: var(--spacing-lg);
}
.alert-warning { background: rgba(253,203,110,0.08); border-color: var(--color-warning); }
.alert-danger { background: rgba(214,48,49,0.08); border-color: var(--color-danger); }
.alert-info { background: rgba(0,212,170,0.08); border-color: var(--color-primary); }
.alert h4 { font-size: 1rem; font-weight: 700; margin-bottom: var(--spacing-xs); }
.alert p { color: var(--color-text-secondary); font-size: 0.9rem; }

/* ===== FAQ ===== */
.faq-item { border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: var(--spacing-md); overflow: hidden; }
.faq-question {
  width: 100%; padding: var(--spacing-lg);
  display: flex; justify-content: space-between; align-items: center;
  font-weight: 600; font-size: 1rem; color: var(--color-text);
  background: var(--color-bg-card); text-align: left;
  transition: background var(--transition-fast);
}
.faq-question:hover { background: var(--color-bg-card-hover); }
.faq-question::after { content: '+'; font-size: 1.4rem; color: var(--color-primary); transition: transform var(--transition-fast); }
.faq-item.active .faq-question::after { content: '−'; }
.faq-answer { padding: 0 var(--spacing-lg) var(--spacing-lg); color: var(--color-text-secondary); font-size: 0.9rem; line-height: 1.8; display: none; }
.faq-item.active .faq-answer { display: block; }

/* ===== 表单 ===== */
.form-group { margin-bottom: var(--spacing-lg); }
.form-label { display: block; font-weight: 600; margin-bottom: var(--spacing-sm); font-size: 0.9rem; }
.form-input, .form-textarea, .form-select {
  width: 100%; padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-bg-secondary); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); color: var(--color-text);
  transition: border-color var(--transition-fast);
}
.form-input:focus, .form-textarea:focus, .form-select:focus { outline: none; border-color: var(--color-primary); }
.form-textarea { min-height: 120px; resize: vertical; }

/* ===== 面包屑 ===== */
.breadcrumb { padding: var(--spacing-md) 0; font-size: 0.85rem; color: var(--color-text-muted); }
.breadcrumb a { color: var(--color-text-secondary); }
.breadcrumb span { margin: 0 var(--spacing-sm); }

/* ===== 标签 ===== */
.tag { display: inline-block; padding: 2px 10px; border-radius: 20px; font-size: 0.75rem; font-weight: 600; background: rgba(0,212,170,0.12); color: var(--color-primary); }
.tag-danger { background: rgba(214,48,49,0.12); color: var(--color-danger); }
.tag-warning { background: rgba(253,203,110,0.12); color: var(--color-warning); }

/* ===== 状态指示 ===== */
.status-dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: var(--spacing-xs); }
.status-green { background: var(--color-primary); }
.status-yellow { background: var(--color-warning); }
.status-red { background: var(--color-danger); }

/* ===== 页脚 ===== */
.site-footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: var(--spacing-2xl); margin-bottom: var(--spacing-2xl); }
.footer-brand p { color: var(--color-text-secondary); font-size: 0.9rem; margin-top: var(--spacing-sm); line-height: 1.7; }
.footer-links h4 { font-size: 0.9rem; font-weight: 700; margin-bottom: var(--spacing-md); color: var(--color-text); }
.footer-links a { display: block; color: var(--color-text-secondary); font-size: 0.85rem; padding: var(--spacing-xs) 0; }
.footer-links a:hover { color: var(--color-primary); }
.footer-bottom { border-top: 1px solid var(--color-border); padding-top: var(--spacing-lg); text-align: center; color: var(--color-text-muted); font-size: 0.8rem; }

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed; bottom: 24px; right: 24px;
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--color-primary); color: var(--color-bg);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem; box-shadow: var(--shadow-md);
  opacity: 0; visibility: hidden; transition: all var(--transition-normal);
  z-index: 999;
}
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { transform: translateY(-3px); box-shadow: var(--shadow-glow); }

/* ===== PWA安装提示 ===== */
.pwa-prompt {
  position: fixed; bottom: 80px; right: 24px;
  background: var(--color-bg-card); border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg); padding: var(--spacing-lg);
  box-shadow: var(--shadow-lg); z-index: 998;
  max-width: 280px; display: none;
}
.pwa-prompt.show { display: block; }
.pwa-prompt h4 { font-size: 0.95rem; margin-bottom: var(--spacing-sm); }
.pwa-prompt p { font-size: 0.8rem; color: var(--color-text-secondary); margin-bottom: var(--spacing-md); }
.pwa-prompt-actions { display: flex; gap: var(--spacing-sm); }

/* ===== 搜索框 ===== */
.search-box { position: relative; max-width: 500px; margin: 0 auto; }
.search-box input { width: 100%; padding: var(--spacing-md) var(--spacing-lg); padding-right: 50px; background: var(--color-bg-card); border: 2px solid var(--color-border); border-radius: 50px; color: var(--color-text); font-size: 1rem; }
.search-box input:focus { border-color: var(--color-primary); outline: none; }
.search-box button { position: absolute; right: 6px; top: 50%; transform: translateY(-50%); width: 38px; height: 38px; border-radius: 50%; background: var(--color-primary); color: var(--color-bg); display: flex; align-items: center; justify-content: center; }
.search-suggestions { position: absolute; top: 100%; left: 0; right: 0; background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-top: var(--spacing-xs); display: none; z-index: 100; }
.search-suggestions.active { display: block; }
.search-suggestions a { display: block; padding: var(--spacing-sm) var(--spacing-lg); color: var(--color-text-secondary); font-size: 0.9rem; border-bottom: 1px solid var(--color-border); }
.search-suggestions a:last-child { border-bottom: none; }
.search-suggestions a:hover { background: var(--color-bg-card-hover); color: var(--color-primary); }

/* ===== 表格 ===== */
.table-wrap { overflow-x: auto; border-radius: var(--radius-md); border: 1px solid var(--color-border); }
table { width: 100%; border-collapse: collapse; }
th, td { padding: var(--spacing-sm) var(--spacing-md); text-align: left; border-bottom: 1px solid var(--color-border); font-size: 0.9rem; }
th { background: var(--color-bg-card); font-weight: 700; color: var(--color-text); }
td { color: var(--color-text-secondary); }

/* ===== 时间线 ===== */
.timeline { position: relative; padding-left: 30px; }
.timeline::before { content: ''; position: absolute; left: 8px; top: 0; bottom: 0; width: 2px; background: var(--color-border); }
.timeline-item { position: relative; margin-bottom: var(--spacing-xl); }
.timeline-item::before { content: ''; position: absolute; left: -26px; top: 6px; width: 12px; height: 12px; border-radius: 50%; background: var(--color-primary); border: 3px solid var(--color-bg); }
.timeline-item h4 { font-size: 0.95rem; font-weight: 700; margin-bottom: var(--spacing-xs); }
.timeline-item time { font-size: 0.8rem; color: var(--color-text-muted); }
.timeline-item p { color: var(--color-text-secondary); font-size: 0.9rem; margin-top: var(--spacing-xs); }

/* ===== 提示成功 ===== */
.toast {
  position: fixed; top: 20px; right: 20px;
  background: var(--color-primary); color: var(--color-bg);
  padding: var(--spacing-md) var(--spacing-xl);
  border-radius: var(--radius-md); font-weight: 600;
  box-shadow: var(--shadow-lg); z-index: 10000;
  transform: translateX(120%); transition: transform var(--transition-normal);
}
.toast.show { transform: translateX(0); }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-desktop { display: none; }
  .nav-mobile-toggle { display: flex; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: var(--spacing-2xl) 0; }
  .section { padding: var(--spacing-2xl) 0; }
  .hero-cta { flex-direction: column; align-items: center; }
}
@media (max-width: 480px) {
  html { font-size: 14px; }
  .container { padding: 0 var(--spacing-sm); }
}