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

:root {
  --bg-deep: #0B0E1A;
  --bg-card: #14192B;
  --bg-card2: #1C2238;
  --brand: #6C7BFF;
  --brand-light: #8B9DFF;
  --brand-glow: rgba(108,123,255,0.15);
  --emotion: #D4B8FF;
  --emotion-glow: rgba(180,140,255,0.15);
  --text-primary: #EDF0F7;
  --text-secondary: #8A92A6;
  --text-muted: #5C6578;
  --amber: #FFB74D;
  --success: #4ADE80;
  --border: rgba(255,255,255,0.06);
  --radius: 20px;
  --radius-sm: 12px;
  --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ===== 星空背景 ===== */
#starfield {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  z-index: 0; pointer-events: none;
}

/* ===== 导航 ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 24px; transition: var(--transition);
}
.nav.scrolled {
  background: rgba(11, 14, 26, 0.85);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1200px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  text-decoration: none; color: var(--text-primary);
}
.logo-moon { font-size: 24px; filter: drop-shadow(0 0 12px rgba(108,123,255,0.5)); }
.logo-text { font-family: 'Quicksand', sans-serif; font-weight: 700; font-size: 20px; letter-spacing: -0.5px; }
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  color: var(--text-secondary); text-decoration: none; font-size: 13px; font-weight: 500;
  transition: var(--transition); position: relative;
}
.nav-links a::after {
  content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px;
  background: var(--brand); border-radius: 2px; transition: var(--transition);
}
.nav-links a:hover { color: var(--text-primary); }
.nav-links a:hover::after { width: 100%; }
.nav-menu-btn { display: none; background: none; border: none; color: var(--text-primary); font-size: 24px; cursor: pointer; }

/* ===== Hero ===== */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  padding: 120px 24px 80px; overflow: hidden; z-index: 1;
}
.hero-glow {
  position: absolute; width: 700px; height: 700px; border-radius: 50%;
  background: radial-gradient(circle, rgba(108,123,255,0.1) 0%, transparent 70%);
  top: 5%; left: 50%; transform: translateX(-50%);
  animation: pulse-glow 6s ease-in-out infinite; pointer-events: none;
}
@keyframes pulse-glow {
  0%, 100% { opacity: 0.5; transform: translateX(-50%) scale(1); }
  50% { opacity: 1; transform: translateX(-50%) scale(1.1); }
}

.hero-content {
  max-width: 1200px; width: 100%;
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center;
}

.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 16px; background: rgba(108,123,255,0.1); border: 1px solid rgba(108,123,255,0.2);
  border-radius: 100px; font-size: 13px; font-weight: 500; color: var(--brand-light);
  margin-bottom: 24px; animation: fade-in-up 0.8s ease-out;
}
.badge-dot { width: 8px; height: 8px; background: var(--success); border-radius: 50%; animation: blink 2s ease-in-out infinite; }
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.3; } }

.hero-title {
  font-size: clamp(32px, 4.5vw, 56px); font-weight: 900; line-height: 1.15;
  letter-spacing: -1.5px; margin-bottom: 24px;
}
.title-line {
  display: block;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--brand-light) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  animation: fade-in-up 0.8s ease-out 0.1s both;
}
.title-line:last-child { animation-delay: 0.2s; }

.hero-desc {
  font-size: 16px; color: var(--text-secondary); line-height: 1.9;
  margin-bottom: 32px; max-width: 520px; animation: fade-in-up 0.8s ease-out 0.3s both;
}
.hero-cta { display: flex; gap: 16px; margin-bottom: 40px; animation: fade-in-up 0.8s ease-out 0.4s both; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 32px; border-radius: 100px; font-size: 15px; font-weight: 600;
  text-decoration: none; cursor: pointer; transition: var(--transition); border: none;
}
.btn-primary {
  background: linear-gradient(135deg, var(--brand) 0%, #5A6BE0 100%); color: white;
  box-shadow: 0 4px 24px rgba(108,123,255,0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(108,123,255,0.5); }
.btn-ghost { background: transparent; color: var(--text-secondary); border: 1px solid var(--border); }
.btn-ghost:hover { color: var(--text-primary); border-color: rgba(255,255,255,0.15); background: rgba(255,255,255,0.03); }

.hero-stats { display: flex; gap: 40px; animation: fade-in-up 0.8s ease-out 0.5s both; }
.stat-num { font-family: 'Quicksand', sans-serif; font-size: 32px; font-weight: 700; color: var(--brand-light); line-height: 1; }
.stat-label { font-size: 12px; color: var(--text-muted); margin-top: 6px; line-height: 1.5; }

/* Hero 右侧双引擎预览 */
.hero-right { animation: fade-in-up 0.8s ease-out 0.3s both; }
.dual-preview {
  display: flex; flex-direction: column; align-items: center; gap: 12px;
}
.preview-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; width: 280px; text-align: center; transition: var(--transition);
}
.preview-card:hover { border-color: rgba(108,123,255,0.2); transform: translateY(-2px); }
.preview-icon { font-size: 32px; margin-bottom: 8px; }
.preview-title { font-size: 15px; font-weight: 700; margin-bottom: 12px; }
.preview-data .preview-title { color: #8B9DFF; }
.preview-emotion .preview-title { color: #D4B8FF; }
.preview-items { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; }
.preview-items span {
  padding: 3px 10px; background: rgba(108,123,255,0.08); border-radius: 100px;
  font-size: 11px; color: var(--text-secondary);
}
.preview-connector { display: flex; flex-direction: column; align-items: center; }
.connector-label {
  font-size: 12px; font-weight: 700; color: var(--brand-light);
  background: rgba(108,123,255,0.1); border: 1px solid rgba(108,123,255,0.2);
  padding: 4px 14px; border-radius: 100px; margin-top: -8px;
}

/* ===== Section 通用 ===== */
section { position: relative; z-index: 1; padding: 100px 24px; }
.section-header { text-align: center; max-width: 640px; margin: 0 auto 64px; }
.section-tag {
  display: inline-block; padding: 6px 16px;
  background: rgba(108,123,255,0.08); border: 1px solid rgba(108,123,255,0.15);
  border-radius: 100px; font-size: 12px; font-weight: 600; color: var(--brand-light);
  text-transform: uppercase; letter-spacing: 1px; margin-bottom: 20px;
}
.section-title { font-size: clamp(28px, 4vw, 44px); font-weight: 800; line-height: 1.2; letter-spacing: -0.5px; margin-bottom: 16px; }
.section-desc { font-size: 16px; color: var(--text-secondary); line-height: 1.7; }

/* ===== 睡眠危机 ===== */
.problem { background: linear-gradient(180deg, transparent 0%, rgba(20,25,43,0.6) 30%, rgba(20,25,43,0.6) 70%, transparent 100%); }
.problem-content { max-width: 1100px; margin: 0 auto; }
.problem-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 60px;
}
.problem-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px 24px; text-align: center; transition: var(--transition);
}
.problem-card:hover { border-color: rgba(108,123,255,0.2); transform: translateY(-4px); }
.problem-num {
  font-family: 'Quicksand', sans-serif; font-size: 48px; font-weight: 700;
  color: var(--brand-light); line-height: 1; margin-bottom: 8px;
}
.problem-num span { font-size: 20px; color: var(--text-muted); margin-left: 2px; }
.problem-label { font-size: 14px; font-weight: 600; color: var(--text-primary); margin-bottom: 12px; }
.problem-desc { font-size: 12px; color: var(--text-muted); line-height: 1.7; }

.problem-quote {
  text-align: center; max-width: 700px; margin: 0 auto;
  padding: 40px; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); position: relative;
}
.problem-quote .quote-mark {
  font-size: 80px; color: rgba(108,123,255,0.1); line-height: 1;
  position: absolute; top: 10px; left: 30px; font-family: Georgia, serif;
}
.problem-quote p { font-size: 17px; color: var(--text-secondary); line-height: 1.9; position: relative; z-index: 1; }
.problem-quote strong { color: var(--text-primary); }

/* ===== 双引擎 ===== */
.dual-engine { background: linear-gradient(180deg, rgba(108,123,255,0.03) 0%, transparent 100%); }
.engine-diagram { max-width: 950px; margin: 0 auto 40px; }
.engine-svg { width: 100%; height: auto; }
.engine-legend {
  display: flex; justify-content: center; gap: 32px; flex-wrap: wrap;
}
.legend-item { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-secondary); }
.legend-dot { width: 12px; height: 12px; border-radius: 50%; }

/* ===== 生态上下游 ===== */
.ecosystem { background: linear-gradient(180deg, transparent 0%, rgba(20,25,43,0.4) 50%, transparent 100%); }
.eco-diagram { max-width: 950px; margin: 0 auto; }
.eco-svg { width: 100%; height: auto; }

/* ===== 改善闭环 ===== */
.loop { background: linear-gradient(180deg, rgba(108,123,255,0.03) 0%, transparent 100%); }
.loop-diagram { max-width: 850px; margin: 0 auto; }
.loop-svg { width: 100%; height: auto; }

/* ===== 核心能力 ===== */
.features { background: linear-gradient(180deg, transparent 0%, rgba(20,25,43,0.5) 50%, transparent 100%); }
.features-grid { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px; transition: var(--transition); position: relative; overflow: hidden;
}
.feature-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(108,123,255,0.3), transparent); opacity: 0; transition: var(--transition);
}
.feature-card:hover { transform: translateY(-4px); border-color: rgba(108,123,255,0.2); box-shadow: 0 20px 60px rgba(0,0,0,0.3), 0 0 40px rgba(108,123,255,0.05); }
.feature-card:hover::before { opacity: 1; }
.feature-main { grid-column: span 2; grid-row: span 1; display: flex; flex-direction: column; justify-content: center; }
.feature-icon { font-size: 36px; margin-bottom: 16px; display: inline-block; }
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 12px; }
.feature-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; margin-bottom: 20px; }
.feature-main p { font-size: 15px; max-width: 500px; }
.feature-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.feature-tags span {
  padding: 4px 12px; background: rgba(108,123,255,0.08); border-radius: 100px;
  font-size: 12px; color: var(--brand-light);
}

/* ===== 场景覆盖 ===== */
.ecosystem-scenes { background: linear-gradient(180deg, rgba(108,123,255,0.03) 0%, transparent 100%); }
.eco-content { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.eco-text .section-tag, .eco-text .section-title, .eco-text .section-desc { text-align: left; }
.eco-list { display: flex; flex-direction: column; gap: 20px; }
.eco-item {
  display: flex; align-items: center; gap: 16px;
  padding: 16px 20px; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-sm); transition: var(--transition);
}
.eco-item:hover { border-color: rgba(108,123,255,0.2); transform: translateX(4px); }
.eco-item-icon { font-size: 28px; width: 48px; height: 48px; display: flex; align-items: center; justify-content: center; background: rgba(108,123,255,0.08); border-radius: 12px; }
.eco-item-text { display: flex; flex-direction: column; }
.eco-item-text strong { font-size: 15px; font-weight: 600; margin-bottom: 2px; }
.eco-item-text span { font-size: 13px; color: var(--text-muted); }

.eco-visual { display: flex; justify-content: center; align-items: center; }
.scene-hub { position: relative; width: 400px; height: 400px; }
.hub-center {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 100px; height: 100px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand) 0%, #5A6BE0 100%);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px;
  box-shadow: 0 0 60px rgba(108,123,255,0.3); z-index: 2;
}
.hub-center span { font-size: 36px; }
.hub-center small { font-size: 11px; color: rgba(255,255,255,0.8); font-weight: 600; }
.hub-node {
  position: absolute; width: 64px; height: 64px; border-radius: 50%;
  background: var(--bg-card2); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center; font-size: 28px;
  z-index: 2; animation: node-pulse 3s ease-in-out infinite;
}
.hub-node-1 { top: 10px; left: 50%; transform: translateX(-50%); animation-delay: 0s; }
.hub-node-2 { top: 50%; right: 10px; transform: translateY(-50%); animation-delay: 0.5s; }
.hub-node-3 { bottom: 10px; left: 50%; transform: translateX(-50%); animation-delay: 1s; }
.hub-node-4 { top: 50%; left: 10px; transform: translateY(-50%); animation-delay: 1.5s; }
@keyframes node-pulse { 0%, 100% { box-shadow: 0 0 0 0 rgba(108,123,255,0.2); } 50% { box-shadow: 0 0 0 12px rgba(108,123,255,0); } }
.hub-lines { position: absolute; top: 0; left: 0; width: 100%; height: 100%; z-index: 1; }
.hub-line { stroke: rgba(108,123,255,0.15); stroke-width: 1; stroke-dasharray: 6 6; animation: dash-flow 2s linear infinite; }
@keyframes dash-flow { to { stroke-dashoffset: -24; } }

/* ===== 下载 ===== */
.download { position: relative; overflow: hidden; }
.download-glow {
  position: absolute; width: 800px; height: 800px; border-radius: 50%;
  background: radial-gradient(circle, rgba(108,123,255,0.08) 0%, transparent 60%);
  top: 50%; left: 50%; transform: translate(-50%, -50%); pointer-events: none;
}
.download-content { position: relative; max-width: 900px; margin: 0 auto; text-align: center; }
.download-platforms { display: flex; gap: 24px; justify-content: center; margin: 48px 0; }
.dl-card {
  position: relative; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 36px; width: 320px; transition: var(--transition);
}
.dl-card:hover { border-color: rgba(108,123,255,0.2); transform: translateY(-4px); }
.dl-card-main { border-color: rgba(108,123,255,0.25); box-shadow: 0 0 60px rgba(108,123,255,0.08); }
.dl-badge {
  position: absolute; top: -1px; right: 24px; padding: 4px 14px;
  background: linear-gradient(135deg, var(--brand) 0%, #5A6BE0 100%); color: white;
  font-size: 11px; font-weight: 700; border-radius: 0 0 8px 8px;
}
.dl-icon { font-size: 48px; margin-bottom: 16px; }
.dl-info { margin-bottom: 20px; }
.dl-label { font-size: 12px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }
.dl-title { font-size: 18px; font-weight: 700; margin-top: 4px; }
.dl-qr { margin-bottom: 20px; }
.qr-placeholder {
  width: 140px; height: 140px; margin: 0 auto; background: var(--bg-deep);
  border: 2px dashed var(--border); border-radius: var(--radius-sm);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
}
.qr-placeholder span { font-size: 13px; color: var(--text-secondary); }
.qr-placeholder small { font-size: 11px; color: var(--text-muted); }
.qr-android { border-color: rgba(108,123,255,0.3); background: rgba(108,123,255,0.05); }
.dl-btn {
  width: 100%; padding: 14px; border-radius: 100px; font-size: 15px; font-weight: 600;
  border: none; cursor: pointer; transition: var(--transition);
  display: flex; align-items: center; justify-content: center; gap: 8px; text-decoration: none;
}
.dl-btn-ios { background: rgba(255,255,255,0.05); color: var(--text-muted); border: 1px solid var(--border); }
.dl-btn-android {
  background: linear-gradient(135deg, var(--brand) 0%, #5A6BE0 100%); color: white;
  box-shadow: 0 4px 24px rgba(108,123,255,0.35);
}
.dl-btn-android:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(108,123,255,0.5); }

.wechat-section {
  display: flex; align-items: center; justify-content: center; gap: 40px;
  margin-top: 64px; padding: 40px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius);
}
.wechat-qr-large { flex-shrink: 0; }
.qr-box {
  width: 180px; height: 180px; background: var(--bg-deep); border: 2px solid var(--border);
  border-radius: var(--radius-sm); display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 12px; position: relative; overflow: hidden;
}
.qr-pattern {
  width: 120px; height: 120px;
  background: repeating-linear-gradient(0deg, var(--text-muted) 0px, var(--text-muted) 4px, transparent 4px, transparent 10px), repeating-linear-gradient(90deg, var(--text-muted) 0px, var(--text-muted) 4px, transparent 4px, transparent 10px);
  opacity: 0.3; border-radius: 4px;
}
.qr-label { font-size: 12px; color: var(--text-muted); }
.wechat-text { text-align: left; }
.wechat-text h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.wechat-text p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* ===== 关于 ===== */
.about { background: linear-gradient(180deg, transparent 0%, rgba(20,25,43,0.3) 100%); }
.about-content { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.about-text .section-tag, .about-text .section-title, .about-text .section-desc { text-align: left; }
.about-stats { display: flex; gap: 40px; margin-top: 36px; }
.about-stat { text-align: center; }
.about-stat strong {
  display: block; font-family: 'Quicksand', sans-serif; font-size: 36px;
  font-weight: 700; color: var(--brand-light); line-height: 1;
}
.about-stat span { font-size: 13px; color: var(--text-muted); margin-top: 6px; display: block; }
.about-visual { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.about-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 28px; text-align: center; transition: var(--transition);
}
.about-card:hover { border-color: rgba(108,123,255,0.2); transform: translateY(-4px); }
.about-card-icon { font-size: 36px; margin-bottom: 12px; }
.about-card-title { font-size: 15px; font-weight: 700; margin-bottom: 4px; }
.about-card-desc { font-size: 12px; color: var(--text-muted); }

/* ===== Footer ===== */
.footer { border-top: 1px solid var(--border); padding: 60px 24px 24px; position: relative; z-index: 1; }
.footer-inner { max-width: 1100px; margin: 0 auto; display: grid; grid-template-columns: 2fr 3fr; gap: 60px; margin-bottom: 40px; }
.footer-brand { max-width: 300px; }
.footer-logo { font-family: 'Quicksand', sans-serif; font-size: 22px; font-weight: 700; margin-bottom: 12px; display: block; }
.footer-brand p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }
.footer-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.footer-col h4 { font-size: 14px; font-weight: 600; margin-bottom: 16px; color: var(--text-primary); }
.footer-col a { display: block; font-size: 14px; color: var(--text-muted); text-decoration: none; margin-bottom: 10px; transition: var(--transition); }
.footer-col a:hover { color: var(--brand-light); }
.footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid var(--border); }
.footer-bottom p { font-size: 12px; color: var(--text-muted); }

/* ===== 动画 ===== */
@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.reveal { opacity: 0; transform: translateY(40px); transition: all 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94); }
.reveal.active { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-content { grid-template-columns: 1fr; text-align: center; gap: 48px; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-stats { justify-content: center; }
  .hero-right { order: -1; }
  .dual-preview { flex-direction: row; flex-wrap: wrap; justify-content: center; }
  .preview-connector { display: none; }

  .problem-grid { grid-template-columns: repeat(2, 1fr); }
  .eco-content, .about-content { grid-template-columns: 1fr; gap: 48px; }
  .eco-text .section-tag, .eco-text .section-title, .eco-text .section-desc,
  .about-text .section-tag, .about-text .section-title, .about-text .section-desc { text-align: center; }
  .eco-visual { order: -1; }
  .scene-hub { width: 300px; height: 300px; }
  .engine-svg, .eco-svg, .loop-svg { max-width: 100%; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-menu-btn { display: block; }
  .features-grid { grid-template-columns: 1fr; }
  .feature-main { grid-column: span 1; }
  .problem-grid { grid-template-columns: 1fr; }
  .download-platforms { flex-direction: column; align-items: center; }
  .dl-card { width: 100%; max-width: 320px; }
  .wechat-section { flex-direction: column; text-align: center; }
  .wechat-text { text-align: center; }
  .about-visual { grid-template-columns: 1fr 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 40px; }
  .footer-brand { max-width: none; text-align: center; }
  .hero-title { font-size: 32px; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
  section { padding: 60px 20px; }
  .engine-legend { flex-direction: column; align-items: center; gap: 12px; }
}

@media (max-width: 480px) {
  .hero-cta { flex-direction: column; }
  .btn { width: 100%; justify-content: center; }
  .about-stats { flex-wrap: wrap; gap: 24px; justify-content: center; }
  .footer-links { grid-template-columns: 1fr; gap: 24px; text-align: center; }
  .dual-preview { flex-direction: column; align-items: center; }
}