/* ============================================================
   汽水音乐官网 - 全站样式
   设计风格:暗色 + 紫橙渐变,符合年轻音乐用户审美
   ============================================================ */

* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0B0B1A;
  --bg-2: #14142A;
  --bg-card: #1C1C36;
  --text: #F2F2F8;
  --text-2: #B8B8D1;
  --primary: #7C3AED;
  --primary-2: #EC4899;
  --accent: #FFB020;
  --border: rgba(255,255,255,0.08);
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --grad-1: linear-gradient(135deg, #7C3AED 0%, #EC4899 50%, #FFB020 100%);
  --grad-2: linear-gradient(180deg, rgba(124,58,237,0.15) 0%, rgba(0,0,0,0) 100%);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--primary-2); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ========== 顶部导航 ========== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(11,11,26,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}
.nav-container {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px; gap: 24px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.logo img { border-radius: 8px; }
.logo-text {
  background: var(--grad-1);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.main-nav ul { display: flex; gap: 28px; list-style: none; }
.main-nav a {
  font-size: 14px; color: var(--text-2); font-weight: 500;
  padding: 6px 0; position: relative;
}
.main-nav a:hover, .main-nav a.active { color: var(--text); }
.main-nav a.active::after {
  content: ''; position: absolute; bottom: -22px; left: 0; right: 0;
  height: 2px; background: var(--grad-1); border-radius: 2px;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; border-radius: 999px; font-weight: 600; font-size: 14px;
  cursor: pointer; border: none; transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}
.btn-primary { background: var(--grad-1); color: #fff; box-shadow: 0 6px 20px rgba(124,58,237,0.45); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(236,72,153,0.55); color: #fff; }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { background: rgba(255,255,255,0.06); color: var(--text); }
.btn-lg { padding: 14px 28px; font-size: 16px; }

/* ========== Hero ========== */
.hero {
  position: relative;
  padding: 80px 0 100px;
  background:
    radial-gradient(circle at 20% 30%, rgba(124,58,237,0.25), transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(236,72,153,0.2), transparent 45%),
    var(--grad-2);
  overflow: hidden;
}
.hero-inner {
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center;
}
.eyebrow {
  display: inline-block; padding: 6px 14px; border-radius: 999px;
  background: rgba(124,58,237,0.15); color: #C4B5FD;
  font-size: 13px; font-weight: 600; margin-bottom: 20px;
  border: 1px solid rgba(124,58,237,0.3);
}
.hero h1 {
  font-size: 48px; line-height: 1.15; font-weight: 800; margin-bottom: 22px; letter-spacing: -0.5px;
}
.highlight {
  background: var(--grad-1);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero .lead { font-size: 17px; color: var(--text-2); margin-bottom: 32px; max-width: 540px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 40px; }
.hero-meta {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
  list-style: none; padding-top: 28px; border-top: 1px solid var(--border);
}
.hero-meta li { display: flex; flex-direction: column; }
.hero-meta strong {
  font-size: 24px; font-weight: 800;
  background: var(--grad-1);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-meta span { font-size: 13px; color: var(--text-2); }
.hero-media img {
  width: 100%; border-radius: 20px;
  box-shadow: 0 30px 80px rgba(124,58,237,0.35), 0 0 0 1px var(--border);
}

/* ========== 平台快入口 ========== */
.platform-strip { padding: 60px 0; background: var(--bg-2); }
.platform-grid {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: 18px;
}
.platform-card {
  background: var(--bg-card); padding: 24px 16px; border-radius: var(--radius);
  text-align: center; border: 1px solid var(--border);
  transition: transform 0.2s, border-color 0.2s, background 0.2s;
}
.platform-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  background: linear-gradient(180deg, rgba(124,58,237,0.12), var(--bg-card));
}
.platform-icon { font-size: 36px; margin-bottom: 10px; }
.platform-name { font-weight: 700; font-size: 15px; margin-bottom: 4px; }
.platform-meta { font-size: 12px; color: var(--text-2); }

/* ========== Section 通用 ========== */
.features, .music-library, .how-to, .faq, .install-guide { padding: 100px 0; }
.section-head { text-align: center; max-width: 700px; margin: 0 auto 56px; }
.section-head .eyebrow { margin-bottom: 14px; }
.section-head h2 {
  font-size: 38px; line-height: 1.2; margin-bottom: 16px; font-weight: 800; letter-spacing: -0.3px;
}
.section-desc { color: var(--text-2); font-size: 16px; }

/* ========== Features ========== */
.feature-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
  background: var(--bg-card); padding: 32px 28px; border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
}
.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--primary);
  box-shadow: 0 18px 40px rgba(124,58,237,0.25);
}
.feature-icon {
  width: 56px; height: 56px; border-radius: 14px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, rgba(124,58,237,0.25), rgba(236,72,153,0.25));
  font-size: 28px; margin-bottom: 18px;
  border: 1px solid rgba(124,58,237,0.4);
}
.feature-card h3 { font-size: 19px; margin-bottom: 10px; font-weight: 700; }
.feature-card p { color: var(--text-2); font-size: 14.5px; }

/* ========== Music Library ========== */
.library-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px;
}
.library-card {
  background: var(--bg-card); padding: 26px 22px; border-radius: var(--radius);
  border: 1px solid var(--border);
}
.library-card h3 { font-size: 18px; margin-bottom: 14px; }
.library-card ul { list-style: none; }
.library-card li {
  padding: 8px 0; color: var(--text-2); font-size: 14px;
  border-bottom: 1px dashed var(--border);
}
.library-card li:last-child { border-bottom: none; }

/* ========== How To ========== */
.steps {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px;
  list-style: none; counter-reset: step;
}
.step {
  background: var(--bg-card); padding: 36px 28px; border-radius: var(--radius);
  border: 1px solid var(--border); position: relative;
}
.step-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--grad-1); color: #fff; font-weight: 800; font-size: 18px;
  margin-bottom: 16px; box-shadow: 0 6px 20px rgba(124,58,237,0.4);
}
.step h3 { font-size: 19px; margin-bottom: 10px; font-weight: 700; }
.step p { color: var(--text-2); font-size: 14.5px; }
.step a { color: var(--primary-2); text-decoration: underline; }

/* ========== FAQ ========== */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-sm); margin-bottom: 12px; padding: 18px 22px;
  transition: border-color 0.2s;
}
.faq-item[open] { border-color: var(--primary); }
.faq-item summary {
  cursor: pointer; font-weight: 600; font-size: 16px;
  list-style: none; display: flex; justify-content: space-between; align-items: center;
}
.faq-item summary::after {
  content: '+'; font-size: 22px; color: var(--primary-2); transition: transform 0.2s;
}
.faq-item[open] summary::after { content: '−'; }
.faq-item p { margin-top: 12px; color: var(--text-2); font-size: 14.5px; }

/* ========== CTA Banner ========== */
.cta-banner {
  padding: 80px 0; text-align: center;
  background:
    linear-gradient(135deg, rgba(124,58,237,0.2), rgba(236,72,153,0.18)),
    var(--bg-2);
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.cta-banner h2 { font-size: 36px; margin-bottom: 14px; font-weight: 800; }
.cta-banner p { color: var(--text-2); font-size: 17px; margin-bottom: 28px; }

/* ========== Download Page Hero ========== */
.page-hero {
  padding: 80px 0 60px; text-align: center;
  background:
    radial-gradient(circle at 50% 0%, rgba(124,58,237,0.25), transparent 50%),
    var(--bg);
}
.page-hero h1 { font-size: 44px; margin-bottom: 18px; font-weight: 800; }
.page-hero .lead { color: var(--text-2); font-size: 17px; max-width: 720px; margin: 0 auto 36px; }
.page-hero-img {
  margin: 0 auto; border-radius: 18px;
  box-shadow: 0 20px 60px rgba(124,58,237,0.3); max-width: 800px;
}

/* ========== Download Cards ========== */
.download-section { padding: 60px 0 100px; background: var(--bg-2); }
.download-card {
  background: var(--bg-card); padding: 36px 40px; border-radius: var(--radius);
  border: 1px solid var(--border); margin-bottom: 22px;
  display: grid; grid-template-columns: 1fr 100px; gap: 28px; align-items: center;
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
}
.download-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: 0 20px 50px rgba(124,58,237,0.25);
}
.platform-badge {
  display: inline-block; padding: 5px 12px; border-radius: 999px;
  background: var(--grad-1); color: #fff; font-size: 12px; font-weight: 700;
  margin-bottom: 12px; letter-spacing: 0.5px;
}
.download-card h2 { font-size: 24px; margin-bottom: 12px; font-weight: 700; }
.download-card p { color: var(--text-2); font-size: 15px; margin-bottom: 18px; }
.download-meta {
  list-style: none; display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px 18px;
  margin-bottom: 22px;
}
.download-meta li { color: var(--text-2); font-size: 13.5px; }
.download-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.download-icon {
  font-size: 72px; text-align: center; line-height: 100px;
  background: linear-gradient(135deg, rgba(124,58,237,0.2), rgba(236,72,153,0.2));
  border-radius: 18px; border: 1px solid var(--border);
}

/* ========== Install Guide ========== */
.guide-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.guide-card {
  background: var(--bg-card); padding: 26px 22px; border-radius: var(--radius);
  border: 1px solid var(--border);
}
.guide-card h3 { font-size: 17px; margin-bottom: 14px; }
.guide-card ol { padding-left: 22px; color: var(--text-2); font-size: 14px; }
.guide-card li { padding: 4px 0; }
.guide-card code {
  background: rgba(124,58,237,0.18); padding: 1px 6px; border-radius: 4px;
  font-size: 13px; color: #C4B5FD;
}

/* ========== Footer ========== */
.site-footer {
  background: var(--bg-2); padding: 60px 0 24px; border-top: 1px solid var(--border);
}
.footer-grid {
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px;
}
.footer-brand img { border-radius: 8px; margin-bottom: 12px; }
.footer-brand p { color: var(--text-2); font-size: 14px; margin-top: 8px; }
.site-footer h4 { font-size: 15px; margin-bottom: 14px; font-weight: 700; }
.site-footer ul { list-style: none; }
.site-footer li { padding: 5px 0; }
.site-footer a { color: var(--text-2); font-size: 14px; }
.site-footer a:hover { color: var(--text); }
.footer-bottom {
  padding-top: 24px; border-top: 1px solid var(--border); text-align: center;
}
.footer-bottom p { color: var(--text-2); font-size: 13px; }

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; text-align: center; }
  .hero .lead { margin-left: auto; margin-right: auto; }
  .hero-meta { max-width: 480px; margin: 0 auto; }
  .hero-cta { justify-content: center; }
  .platform-grid { grid-template-columns: repeat(3, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .library-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .download-card { grid-template-columns: 1fr; text-align: center; }
  .download-icon { display: none; }
  .download-meta { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .main-nav { display: none; }
  .nav-cta { padding: 8px 14px; font-size: 13px; }
  .hero { padding: 50px 0 60px; }
  .hero h1 { font-size: 34px; }
  .section-head h2 { font-size: 28px; }
  .page-hero h1 { font-size: 32px; }
  .platform-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: 1fr; }
  .library-grid { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-meta { grid-template-columns: repeat(2, 1fr); }
  .cta-banner h2 { font-size: 26px; }
}