/* ===== Reset & Base ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --primary: #4f46e5;
  --primary-light: #6366f1;
  --primary-dark: #3730a3;
  --primary-glow: rgba(79,70,229,.15);
  --accent: #818cf8;
  --accent-light: #a5b4fc;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --bg-dark: #0f172a;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --success: #10b981;
  --success-bg: #ecfdf5;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.04), 0 1px 2px rgba(0,0,0,.06);
  --shadow: 0 4px 24px rgba(0,0,0,.06);
  --shadow-lg: 0 12px 48px rgba(0,0,0,.08);
  --shadow-xl: 0 24px 80px rgba(0,0,0,.1);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 8px;
  --transition: .3s cubic-bezier(.4,0,.2,1);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--text); background: var(--bg);
  line-height: 1.7; -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 28px; }
.section { padding: 120px 0; }
.section-alt { background: var(--bg-alt); }

.section-header { text-align: center; margin-bottom: 72px; }
.section-header h2 {
  font-size: 40px; font-weight: 800; color: var(--text);
  margin-bottom: 16px; letter-spacing: -1px; line-height: 1.2;
}
.section-header p { font-size: 18px; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* ===== 按钮 ===== */
.btn-primary {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 13px 30px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff; font-size: 15px; font-weight: 600;
  border-radius: var(--radius-xs); border: none; cursor: pointer;
  transition: all var(--transition);
  box-shadow: 0 4px 16px var(--primary-glow);
  position: relative; overflow: hidden;
}
.btn-primary::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, transparent 40%, rgba(255,255,255,.1) 50%, transparent 60%);
  background-size: 200% 200%; animation: shimmer 2s infinite;
}
@keyframes shimmer { 0% { background-position: 200% 0 } 100% { background-position: -200% 0 } }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(79,70,229,.35); }
.btn-lg { padding: 16px 40px; font-size: 16px; border-radius: var(--radius-sm); }
.btn-outline {
  display: inline-flex; align-items: center;
  padding: 11px 24px; border: 1.5px solid var(--border);
  color: var(--text-secondary); font-size: 14px; font-weight: 500;
  border-radius: var(--radius-xs); background: transparent;
  transition: all var(--transition);
}
.btn-outline:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-glow); }
.btn-ghost {
  display: inline-flex; align-items: center;
  padding: 16px 40px; color: var(--text-secondary);
  font-size: 16px; font-weight: 500; border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.btn-ghost:hover { color: var(--primary); }

/* ===== 导航 ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,.88); backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid transparent; transition: all var(--transition);
}
.header.scrolled { border-bottom-color: var(--border); box-shadow: var(--shadow-sm); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.logo-wrap { display: flex; align-items: center; gap: 12px; }
.logo-img { width: 40px; height: 40px; border-radius: 10px; }
.logo-text {
  font-size: 22px; font-weight: 800; letter-spacing: -.5px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.nav-links { display: flex; gap: 36px; }
.nav-links a { font-size: 15px; color: var(--text-secondary); font-weight: 500; transition: color var(--transition); position: relative; }
.nav-links a:hover { color: var(--primary); }
.nav-links a.active { color: var(--primary); font-weight: 600; }
.nav-links a.active::after {
  content: ''; position: absolute; left: 0; right: 0; bottom: -8px;
  height: 2px; border-radius: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}
.nav-actions { display: flex; gap: 12px; align-items: center; }

/* 移动端汉堡菜单按钮 */
.nav-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  width: 42px; height: 42px; padding: 10px;
  background: transparent; border: none; cursor: pointer; border-radius: var(--radius-xs);
  transition: background var(--transition);
}
.nav-toggle:hover { background: var(--primary-glow); }
.nav-toggle span {
  display: block; height: 2px; width: 100%; border-radius: 2px;
  background: var(--text); transition: all var(--transition);
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 主视觉区 ===== */
.hero {
  padding: 180px 0 100px;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(79,70,229,.06) 0%, transparent 60%),
              linear-gradient(180deg, #faf9ff 0%, #ffffff 100%);
  overflow: hidden;
}
.hero .container { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.hero-title {
  font-size: 56px; font-weight: 900; line-height: 1.15;
  letter-spacing: -1.5px; color: var(--text); margin-bottom: 24px;
}
.hero-title span {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 60%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-subtitle {
  font-size: 18px; color: var(--text-secondary); line-height: 1.9; margin-bottom: 36px;
}
.hero-actions { display: flex; gap: 16px; margin-bottom: 32px; }

.hero-trial { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 48px; }
.trial-item {
  font-size: 14px; font-weight: 600; color: var(--primary);
  background: var(--primary-glow); padding: 8px 18px;
  border-radius: 24px; white-space: nowrap;
  border: 1px solid rgba(79,70,229,.12);
}
.hero-stats { display: flex; gap: 56px; padding-top: 32px; border-top: 1px solid var(--border-light); }
.stat-item { display: flex; flex-direction: column; }
.stat-num {
  font-size: 32px; font-weight: 800; letter-spacing: -1px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.stat-label { font-size: 13px; color: var(--text-muted); margin-top: 6px; font-weight: 500; }

/* Hero Mockup */
.hero-visual { perspective: 1000px; }
.hero-mockup {
  background: #fff; border-radius: var(--radius);
  box-shadow: var(--shadow-xl); overflow: hidden;
  border: 1px solid var(--border); transform: rotateY(-4deg) rotateX(2deg);
  transition: transform var(--transition);
}
.hero-mockup:hover { transform: rotateY(0) rotateX(0); }
.mockup-bar {
  height: 40px; background: #f8fafc; border-bottom: 1px solid var(--border-light);
  display: flex; align-items: center; gap: 8px; padding: 0 16px;
}
.mockup-bar span { width: 12px; height: 12px; border-radius: 50%; }
.mockup-bar span:nth-child(1) { background: #ef4444; }
.mockup-bar span:nth-child(2) { background: #f59e0b; }
.mockup-bar span:nth-child(3) { background: #22c55e; }
.mockup-body { display: flex; height: 380px; }
.mockup-sidebar {
  width: 210px; background: #fafbfc; border-right: 1px solid var(--border-light);
  display: flex; flex-direction: column; padding: 14px 10px; gap: 4px;
}
.mockup-session-title {
  font-size: 12px; font-weight: 700; color: var(--text-muted);
  padding: 2px 10px 10px; letter-spacing: 1px;
}
.mockup-session {
  display: flex; align-items: center; gap: 10px; padding: 10px;
  border-radius: 10px; position: relative; transition: background var(--transition);
}
.mockup-session:hover { background: #f1f5f9; }
.mockup-session.active { background: var(--primary-glow); }
.mockup-session.active::before {
  content: ''; position: absolute; left: 0; top: 12px; bottom: 12px;
  width: 3px; border-radius: 2px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
}
.mockup-session-avatar {
  width: 36px; height: 36px; border-radius: 50%; flex-shrink: 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700;
}
.mockup-session-avatar.av-green { background: linear-gradient(135deg, #10b981, #34d399); }
.mockup-session-avatar.av-orange { background: linear-gradient(135deg, #f59e0b, #fbbf24); }
.mockup-session-avatar.av-blue { background: linear-gradient(135deg, #3b82f6, #60a5fa); }
.mockup-session-info { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 3px; }
.mockup-session-name { font-size: 13px; font-weight: 600; color: var(--text); }
.mockup-session-preview {
  font-size: 11px; color: var(--text-muted);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.mockup-session-badge {
  flex-shrink: 0; min-width: 18px; height: 18px; padding: 0 5px;
  border-radius: 9px; background: var(--primary); color: #fff;
  font-size: 10px; font-weight: 700; line-height: 18px; text-align: center;
}
.mockup-chat { flex: 1; padding: 20px; display: flex; flex-direction: column; gap: 14px; overflow-y: auto; }
.mockup-msg { max-width: 85%; padding: 12px 16px; border-radius: 14px; font-size: 13px; line-height: 1.6; }
.mockup-msg.visitor {
  align-self: flex-end; border-bottom-right-radius: 4px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff; box-shadow: 0 2px 8px var(--primary-glow);
}
.mockup-msg.agent {
  align-self: flex-start; border-bottom-left-radius: 4px;
  background: #f1f5f9; color: var(--text);
}

/* ===== 三列卡片 ===== */
.cards-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.card {
  background: #fff; border-radius: var(--radius); padding: 40px 32px;
  border: 1px solid var(--border); transition: all var(--transition);
  position: relative; overflow: hidden;
}
.card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0;
  height: 3px; background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0; transition: opacity var(--transition);
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); border-color: var(--accent-light); }
.card:hover::before { opacity: 1; }
.card-icon { margin-bottom: 20px; display: block; color: var(--primary); }
.card-icon svg { display: block; }
.card h3 { font-size: 22px; font-weight: 700; margin-bottom: 18px; color: var(--text); }
.card-list { display: flex; flex-direction: column; gap: 12px; }
.card-list li {
  font-size: 14px; color: var(--text-secondary); padding-left: 22px; position: relative; line-height: 1.6;
}
.card-list li::before {
  content: ''; position: absolute; left: 0; top: 8px;
  width: 7px; height: 7px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
}

/* ===== 功能网格 ===== */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feat-item {
  text-align: center; padding: 32px 20px; border-radius: var(--radius);
  transition: all var(--transition); border: 1px solid transparent;
}
.feat-item:hover { background: #fff; box-shadow: var(--shadow); border-color: var(--border); transform: translateY(-3px); }
.feat-icon { margin-bottom: 14px; display: block; color: var(--primary); }
.feat-icon svg { display: block; margin: 0 auto; }
.feat-item h4 { font-size: 16px; font-weight: 600; margin-bottom: 8px; color: var(--text); }
.feat-item p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ===== 优势卡片 ===== */
.card-accent { text-align: center; }
.card-accent h3 { font-size: 20px; margin-bottom: 12px; }
.card-accent p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* ===== 价格卡片 ===== */
.pricing-cards {
  display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 28px; max-width: 800px; margin: 0 auto;
}
.pricing-card {
  background: #fff; border-radius: var(--radius); border: 2px solid var(--border);
  padding: 48px 36px; text-align: center; position: relative; transition: all var(--transition);
}
.pricing-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); }
.pricing-featured {
  border-color: var(--primary); background: linear-gradient(180deg, #faf9ff 0%, #fff 40%);
  box-shadow: 0 0 0 4px var(--primary-glow), var(--shadow-lg);
}
.pricing-badge {
  position: absolute; top: -15px; left: 50%; transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff; font-size: 13px; font-weight: 700; padding: 5px 24px; border-radius: 20px;
  box-shadow: 0 4px 12px var(--primary-glow); letter-spacing: .5px;
}
.pricing-header h3 { font-size: 22px; font-weight: 700; color: var(--text); margin-bottom: 20px; }
.pricing-price { display: flex; align-items: baseline; justify-content: center; gap: 4px; margin-bottom: 4px; }
.pricing-num {
  font-size: 56px; font-weight: 900; letter-spacing: -2px; line-height: 1;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.pricing-unit { font-size: 22px; font-weight: 700; color: var(--text); }
.pricing-period { font-size: 14px; color: var(--text-muted); margin-bottom: 28px; }
.pricing-save {
  font-size: 14px; color: var(--success); font-weight: 600;
  margin-top: -20px; margin-bottom: 28px; background: var(--success-bg);
  display: inline-block; padding: 4px 14px; border-radius: 20px;
}
.pricing-features {
  list-style: none; text-align: left; margin-bottom: 32px;
  display: flex; flex-direction: column; gap: 12px;
}
.pricing-features li {
  font-size: 14px; color: var(--text-secondary); padding-left: 24px; position: relative;
}
.pricing-features li::before {
  content: '✓'; position: absolute; left: 0; color: var(--success); font-weight: 700; font-size: 14px;
}
.pricing-btn { width: 100%; }

/* ===== 安全四列 ===== */
.cards-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.sec-card {
  text-align: center; padding: 36px 24px; border-radius: var(--radius);
  transition: all var(--transition); border: 1px solid transparent;
}
.sec-card:hover { background: #fff; box-shadow: var(--shadow); border-color: var(--border); transform: translateY(-3px); }
.sec-icon { margin-bottom: 18px; display: block; color: var(--primary); }
.sec-icon svg { display: block; margin: 0 auto; }
.sec-card h4 { font-size: 17px; font-weight: 600; margin-bottom: 10px; color: var(--text); }
.sec-card p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ===== CTA ===== */
.cta-section {
  text-align: center; padding: 100px 0;
  background: radial-gradient(ellipse 60% 80% at 50% 50%, rgba(79,70,229,.15) 0%, transparent 60%),
              linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff; position: relative; overflow: hidden;
}
.cta-section::before {
  content: ''; position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: .5;
}
.cta-section h2 { font-size: 40px; font-weight: 800; margin-bottom: 12px; position: relative; }
.cta-section p { font-size: 18px; opacity: .85; margin-bottom: 40px; position: relative; }
.cta-actions { display: flex; gap: 16px; justify-content: center; position: relative; }
.cta-section .btn-primary {
  background: #fff; color: var(--primary); box-shadow: 0 4px 20px rgba(0,0,0,.15);
}
.cta-section .btn-primary:hover { background: #f8fafc; transform: translateY(-2px); box-shadow: 0 8px 30px rgba(0,0,0,.2); }
.cta-section .btn-primary::after { display: none; }
.cta-section .btn-ghost { color: rgba(255,255,255,.9); border: 1.5px solid rgba(255,255,255,.25); border-radius: var(--radius-sm); }
.cta-section .btn-ghost:hover { background: rgba(255,255,255,.1); color: #fff; border-color: rgba(255,255,255,.4); }

/* ===== 页脚 ===== */
.footer { background: var(--bg-dark); color: #94a3b8; padding: 64px 0 0; }
.footer-inner { display: flex; justify-content: space-between; gap: 60px; padding-bottom: 44px; border-bottom: 1px solid rgba(255,255,255,.06); }
.footer-brand h3 { font-size: 22px; font-weight: 700; color: #fff; margin-bottom: 8px; }
.footer-brand p { font-size: 14px; }
.footer-links { display: flex; gap: 72px; }
.footer-links dt { font-size: 14px; font-weight: 600; color: #fff; margin-bottom: 14px; }
.footer-links dd { font-size: 13px; margin-bottom: 10px; }
.footer-links dd a { transition: color var(--transition); }
.footer-links dd a:hover { color: #fff; }
.footer-bottom { padding: 24px 0; text-align: center; font-size: 13px; }
.footer-bottom a { color: var(--text-muted); transition: color var(--transition); }
.footer-bottom a:hover { color: #fff; }

/* ===== 下载区块 ===== */
.download-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 24px; max-width: 900px; margin: 0 auto;
}
.download-card {
  background: #fff; border-radius: var(--radius); border: 2px solid var(--border);
  padding: 36px 24px; text-align: center; text-decoration: none;
  transition: all var(--transition); color: inherit; display: block;
}
.download-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.download-icon { margin-bottom: 16px; color: var(--primary); }
.download-card h4 { font-size: 17px; font-weight: 600; color: var(--text); margin: 0 0 6px; }
.download-card p { font-size: 13px; color: var(--text-muted); margin: 0 0 16px; }
.download-btn {
  display: inline-block; background: var(--primary); color: #fff;
  padding: 8px 28px; border-radius: 6px; font-size: 14px; font-weight: 600;
  transition: all var(--transition);
}
.download-card:hover .download-btn { background: var(--primary-dark); }

/* ===== 子页面 Hero（页面级横幅） ===== */
.page-hero {
  padding: 160px 0 80px;
  text-align: center;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(79,70,229,.07) 0%, transparent 60%),
              linear-gradient(180deg, #faf9ff 0%, #ffffff 100%);
}
.page-hero h1 {
  font-size: 48px; font-weight: 900; letter-spacing: -1px;
  line-height: 1.2; color: var(--text); margin-bottom: 20px;
}
.page-hero h1 span {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 60%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.page-hero p {
  font-size: 18px; color: var(--text-secondary); max-width: 640px; margin: 0 auto;
}
.page-hero .hero-actions { justify-content: center; margin: 36px 0 0; }
.page-hero .hero-trial { justify-content: center; margin: 32px 0 0; }
.page-hero .hero-stats { justify-content: center; gap: 64px; max-width: 720px; margin: 40px auto 0; }

/* ===== 三列功能网格（首页功能概览） ===== */
.features-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

/* 查看全部按钮行 */
.more-row { text-align: center; margin-top: 48px; }

/* ===== 功能分组（产品功能页） ===== */
.features-group { margin-bottom: 64px; }
.features-group:last-child { margin-bottom: 0; }
.features-group-head {
  display: flex; align-items: center; gap: 14px; margin-bottom: 28px;
  padding-bottom: 16px; border-bottom: 1px solid var(--border-light);
}
.features-group-head .fg-icon {
  width: 44px; height: 44px; border-radius: 12px; flex-shrink: 0;
  background: var(--primary-glow); color: var(--primary);
  display: flex; align-items: center; justify-content: center;
}
.features-group-head h3 { font-size: 22px; font-weight: 700; color: var(--text); }

/* ===== 快捷入口卡片（首页/页尾导航） ===== */
.card-link {
  display: block; text-align: center; cursor: pointer;
}
.card-link .card-icon { color: var(--primary); }
.card-link .card-arrow {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14px; font-weight: 600; color: var(--primary);
  margin-top: 6px; transition: gap var(--transition);
}
.card-link:hover .card-arrow { gap: 12px; }

/* ===== FAQ 折叠列表（价格页） ===== */
.faq-list { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 16px; }
.faq-list details {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 22px 28px; transition: all var(--transition);
}
.faq-list details:hover { border-color: var(--accent-light); }
.faq-list details[open] { border-color: var(--primary); box-shadow: var(--shadow); }
.faq-list summary {
  cursor: pointer; font-size: 16px; font-weight: 600; color: var(--text);
  list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: '+'; font-size: 22px; font-weight: 400; color: var(--primary);
  transition: transform var(--transition); flex-shrink: 0;
}
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list .faq-answer {
  margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--border-light);
  font-size: 14px; color: var(--text-secondary); line-height: 1.8;
}

/* ===== 安全实践清单（安全页） ===== */
.practice-list { max-width: 860px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.practice-item {
  display: flex; gap: 16px; align-items: flex-start;
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: all var(--transition);
}
.practice-item:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--accent-light); }
.practice-check {
  width: 28px; height: 28px; border-radius: 50%; flex-shrink: 0;
  background: var(--success-bg); color: var(--success); font-weight: 700;
  display: flex; align-items: center; justify-content: center; margin-top: 2px;
}
.practice-item h4 { font-size: 16px; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.practice-item p { font-size: 13px; color: var(--text-muted); line-height: 1.7; }

/* ===== 使用步骤（下载页） ===== */
.steps-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; max-width: 960px; margin: 0 auto;
}
.step-card { text-align: center; position: relative; padding: 32px 24px; }
.step-num {
  width: 56px; height: 56px; margin: 0 auto 20px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  color: #fff; font-size: 22px; font-weight: 800;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 20px var(--primary-glow);
}
.step-card h4 { font-size: 18px; font-weight: 700; color: var(--text); margin-bottom: 10px; }
.step-card p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }
.step-line {
  position: absolute; top: 60px; left: calc(50% + 48px); right: calc(-50% + 48px);
  height: 2px; background: linear-gradient(90deg, var(--accent-light), transparent);
  display: block;
}
.step-card:last-child .step-line { display: none; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero .container { grid-template-columns: 1fr; gap: 48px; }
  .hero-title { font-size: 40px; }
  .hero-visual { max-width: 520px; margin: 0 auto; }
  .cards-3 { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .features-grid-3 { grid-template-columns: repeat(2, 1fr); }
  .cards-4 { grid-template-columns: repeat(2, 1fr); }
  .pricing-cards { grid-template-columns: 1fr; max-width: 420px; }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .practice-list { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-links {
    display: none; position: fixed; top: 72px; left: 0; right: 0; z-index: 999;
    flex-direction: column; gap: 0;
    background: rgba(255,255,255,.98); backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border); box-shadow: var(--shadow);
    padding: 8px 28px 16px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 14px 0; font-size: 16px; border-bottom: 1px solid var(--border-light); }
  .nav-links a:last-child { border-bottom: none; }
  .nav-links a.active::after { display: none; }
  .nav-links a.active { color: var(--primary); }
  .nav-actions .btn-outline { display: none; }
  .page-hero { padding: 130px 0 60px; }
  .page-hero h1 { font-size: 32px; }
  .hero { padding: 130px 0 60px; }
  .hero-title { font-size: 32px; }
  .hero-subtitle { font-size: 15px; }
  .mockup-sidebar { width: 160px; }
  .mockup-session { padding: 8px; gap: 8px; }
  .mockup-session-avatar { width: 30px; height: 30px; font-size: 12px; }
  .hero-actions { flex-direction: column; }
  .hero-stats { gap: 28px; }
  .page-hero .hero-stats { gap: 24px; flex-wrap: wrap; }
  .hero-trial { gap: 8px; }
  .section { padding: 72px 0; }
  .section-header h2 { font-size: 28px; }
  .section-header p { font-size: 15px; }
  .features-grid { grid-template-columns: 1fr; }
  .features-grid-3 { grid-template-columns: 1fr; }
  .cards-4 { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .step-line { display: none; }
  .footer-inner { flex-direction: column; gap: 36px; }
  .footer-links { flex-wrap: wrap; gap: 36px; }
}