/* ============== 重置 + 基础 ============== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: #1a1a1a;
  background: #ffffff;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: opacity .2s; }
a:hover { opacity: .8; }
button { font: inherit; cursor: pointer; border: none; background: none; }

:root {
  --primary: #CA0000;
  --primary-dark: #a00000;
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --bg-dark: #0f0f10;
  --border: #e5e5e7;
  --text: #1a1a1a;
  --text-2: #555;
  --text-3: #94a3b8;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.06);
  --shadow-md: 0 6px 20px rgba(0,0,0,.08);
  --shadow-lg: 0 20px 60px rgba(0,0,0,.12);
  --radius: 12px;
}

.container { width: 92%; max-width: 1100px; margin: 0 auto; }

/* ============== Topbar ============== */
.topbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  display: flex; justify-content: space-between; align-items: center;
  height: 60px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { width: 32px; height: 32px; border-radius: 8px; }
.brand-name { font-size: 18px; font-weight: 700; }
.topbar-nav { display: flex; gap: 28px; }
.topbar-nav a { font-size: 15px; color: var(--text-2); }
.topbar-nav a:hover { color: var(--primary); }

/* ============== Hero ============== */
.hero {
  padding: 80px 0 100px;
  background:
    radial-gradient(1200px 600px at 90% 10%, rgba(202,0,0,.06), transparent 50%),
    radial-gradient(900px 500px at 10% 90%, rgba(202,0,0,.04), transparent 50%),
    var(--bg);
  overflow: hidden;
}
.hero-inner {
  display: grid; grid-template-columns: 1.1fr 1fr;
  gap: 60px; align-items: center;
}
.hero-tag {
  display: inline-block;
  padding: 6px 12px; margin-bottom: 24px;
  background: rgba(202,0,0,.08); color: var(--primary);
  border-radius: 100px; font-size: 13px; font-weight: 500;
}
.hero-title {
  font-size: 58px; font-weight: 800; line-height: 1.1;
  letter-spacing: -1px; margin-bottom: 24px;
}
.hero-title .accent { color: var(--primary); }
.hero-desc {
  font-size: 17px; color: var(--text-2);
  line-height: 1.7; margin-bottom: 36px;
}
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-foot { margin-top: 18px; font-size: 13px; color: var(--text-3); }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 10px;
  font-size: 15px; font-weight: 600;
  transition: all .2s;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn svg { display: block; }
.btn-primary {
  background: var(--text); color: #fff;
}
.btn-primary:hover { background: var(--primary); }
.btn-secondary {
  background: #fff; color: var(--text);
  border: 1.5px solid var(--border);
}
.btn-secondary:hover { border-color: var(--text); }
.btn-lg {
  padding: 14px 28px; font-size: 16px;
}

/* 手机框 */
.phone-frame {
  position: relative;
  width: 100%; max-width: 320px;
  aspect-ratio: 9 / 19.5;
  margin: 0 auto;
  background: #1a1a1a;
  border-radius: 36px;
  padding: 12px;
  box-shadow: var(--shadow-lg);
}
.phone-frame::before {
  content: ''; position: absolute; top: 8px; left: 50%;
  transform: translateX(-50%);
  width: 80px; height: 22px;
  background: #1a1a1a; border-radius: 12px;
  z-index: 2;
}
.phone-frame img {
  width: 100%; height: 100%;
  border-radius: 28px; object-fit: cover;
}
.phone-caption {
  display: block; text-align: center;
  margin-top: 16px; font-size: 14px; color: var(--text-2);
  font-weight: 500;
}

/* ============== Features ============== */
.features {
  padding: 100px 0;
  background: var(--bg-alt);
}
.section-title {
  font-size: 40px; font-weight: 700;
  text-align: center; margin-bottom: 12px;
  letter-spacing: -.5px;
}
.section-sub {
  font-size: 17px; color: var(--text-2);
  text-align: center; margin-bottom: 60px;
}
.feature-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  background: #fff; padding: 32px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: all .25s;
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: transparent;
}
.feature-icon {
  width: 52px; height: 52px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
}
.feature-card h3 {
  font-size: 19px; font-weight: 600;
  margin-bottom: 10px;
  display: flex; align-items: center; gap: 8px;
}
.feature-card p {
  font-size: 14.5px; color: var(--text-2);
  line-height: 1.7;
}
.badge-svip {
  display: inline-block;
  padding: 2px 8px;
  background: #7B1FA2; color: #fff;
  border-radius: 4px;
  font-size: 11px; font-weight: 700;
  letter-spacing: .5px;
}

/* ============== Screenshots ============== */
.screenshots { padding: 100px 0; background: var(--bg-dark); color: #fff; }
.screenshots .section-title { color: #fff; }
.screenshots .section-sub { color: #9ca3af; }
.screen-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  max-width: 900px; margin: 0 auto;
}
.screenshots .phone-frame {
  background: #2a2a2a;
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
}
.screenshots .phone-caption { color: #d4d4d8; }

/* ============== CTA ============== */
.cta {
  padding: 100px 0;
  background: linear-gradient(135deg, #fff 0%, #fef2f2 100%);
}
.cta-inner { text-align: center; }
.cta h2 {
  font-size: 36px; font-weight: 700;
  margin-bottom: 14px;
  letter-spacing: -.5px;
}
.cta p {
  font-size: 16px; color: var(--text-2);
  margin-bottom: 32px;
}
.cta .hero-cta { justify-content: center; }

/* ============== Footer ============== */
.footer {
  background: #0a0a0b; color: #b3b3b8;
  padding: 60px 0 0;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 40px;
  padding-bottom: 40px;
}
.footer-brand { display: flex; flex-direction: column; gap: 14px; }
.footer-logo { width: 40px; height: 40px; border-radius: 8px; }
.footer-brand span { font-size: 14px; }
.footer-col h4 {
  color: #fff; font-size: 15px; font-weight: 600;
  margin-bottom: 18px;
}
.footer-col a {
  display: block;
  font-size: 14px; color: #94a3b8;
  margin-bottom: 10px;
}
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid #222;
  padding: 24px 0;
}
.footer-bottom .container {
  display: flex; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  font-size: 13px; color: #6b7280;
}
.footer-bottom a { color: #6b7280; }
.footer-bottom a:hover { color: #b3b3b8; }

/* ============== Toast ============== */
.toast {
  position: fixed; bottom: 30px; left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: rgba(20,20,20,.92);
  color: #fff;
  padding: 12px 24px;
  border-radius: 100px;
  font-size: 14px;
  box-shadow: 0 6px 24px rgba(0,0,0,.3);
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s, transform .25s;
  z-index: 1000;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============== 响应式 ============== */
@media (max-width: 900px) {
  .hero { padding: 50px 0 70px; }
  .hero-inner { grid-template-columns: 1fr; gap: 50px; }
  .hero-text { text-align: center; }
  .hero-title { font-size: 44px; }
  .hero-cta { justify-content: center; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .screen-grid { grid-template-columns: 1fr; max-width: 320px; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .topbar-nav { gap: 16px; }
  .topbar-nav a { font-size: 14px; }
}

@media (max-width: 540px) {
  .hero-title { font-size: 36px; }
  .hero-desc { font-size: 15px; }
  .section-title { font-size: 30px; }
  .section-sub { font-size: 15px; margin-bottom: 40px; }
  .features, .screenshots, .cta { padding: 70px 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 24px; }
  .footer-bottom .container { justify-content: center; text-align: center; }
  .cta h2 { font-size: 26px; }
  .topbar-nav { display: none; }
  .btn { padding: 11px 18px; font-size: 14px; }
  .btn-lg { padding: 13px 24px; font-size: 15px; }
}