/* MaxSV AI — 单页官网样式（双主题：浅色默认，深色跟随系统） */
:root {
  color-scheme: light dark;
  --bg: #f5f7fa;
  --bg-elevated: #ffffff;
  --accent: #0e7490;
  --accent-rgb: 14, 116, 144;
  --accent-dim: rgba(14, 116, 144, 0.55);
  --text: #1e293b;
  --text-dim: #475569;
  --border: rgba(15, 23, 42, 0.12);
  --nav-bg: rgba(245, 247, 250, 0.85);
  --radius: 14px;
  --max-width: 1080px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0f1e;
    --bg-elevated: #101728;
    --accent: #22d3ee;
    --accent-rgb: 34, 211, 238;
    --accent-dim: rgba(34, 211, 238, 0.6);
    --text: #e2e8f0;
    --text-dim: #94a3b8;
    --border: rgba(148, 163, 184, 0.16);
    --nav-bg: rgba(10, 15, 30, 0.82);
  }
}

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

html { scroll-behavior: smooth; }

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

/* ---------- 导航 ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 32px;
  transition: background 0.3s, box-shadow 0.3s, padding 0.3s;
}
.nav.scrolled {
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 var(--border);
  padding: 12px 32px;
}
.nav-logo { font-size: 1.2rem; font-weight: 700; color: var(--text); text-decoration: none; }
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--text-dim); text-decoration: none; font-size: 0.95rem; transition: color 0.2s; }
.nav-links a:hover { color: var(--accent); }

/* ---------- Hero ---------- */
.hero {
  position: relative; min-height: 92vh;
  display: flex; align-items: center; justify-content: center;
  text-align: center; overflow: hidden; padding: 0 24px;
}
#graph-bg { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0.55; }
.hero-content { position: relative; z-index: 1; max-width: 820px; }
.hero-kicker { color: var(--accent); font-size: 0.9rem; letter-spacing: 0.35em; margin-bottom: 18px; }
.hero h1 { font-size: clamp(2.6rem, 7vw, 4.5rem); font-weight: 800; line-height: 1.15; }
.hero h1 span { color: var(--accent); }
.hero-tagline { font-size: clamp(1.1rem, 2.5vw, 1.5rem); margin-top: 16px; }
.hero-sub { color: var(--text-dim); max-width: 640px; margin: 18px auto 0; }
.hero-cta {
  display: inline-block; margin-top: 36px; padding: 13px 34px;
  border: 1px solid var(--accent-dim); border-radius: 999px;
  color: var(--accent); text-decoration: none; font-weight: 600;
  transition: background 0.25s, box-shadow 0.25s;
}
.hero-cta:hover { background: rgba(var(--accent-rgb), 0.1); box-shadow: 0 0 24px rgba(var(--accent-rgb), 0.25); }

/* ---------- 区块通用 ---------- */
section { padding: 96px 24px; }
.container { max-width: var(--max-width); margin: 0 auto; }
.section-title { font-size: 1.9rem; font-weight: 700; margin-bottom: 12px; }
.section-title::before { content: "◆ "; color: var(--accent); font-size: 1.05rem; vertical-align: 3px; }
.section-intro { color: var(--text-dim); max-width: 640px; margin-bottom: 48px; }

/* ---------- 能力卡片 ---------- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}
.card:hover { transform: translateY(-4px); border-color: var(--accent-dim); box-shadow: 0 0 28px rgba(var(--accent-rgb), 0.12); }
.card-icon { width: 44px; height: 44px; margin-bottom: 20px; color: var(--accent); }
.card h3 { font-size: 1.2rem; margin-bottom: 12px; }
.card p { color: var(--text-dim); font-size: 0.97rem; }

/* ---------- 关于 ---------- */
.about-text { max-width: 760px; color: var(--text-dim); }
.about-text strong { color: var(--text); font-weight: 600; }
.about-text p + p { margin-top: 16px; }

/* ---------- 联系 ---------- */
#contact .section-intro { margin-left: auto; margin-right: auto; }
#contact { text-align: center; }
.contact-mail { font-size: 1.3rem; color: var(--accent); text-decoration: none; font-weight: 600; }
.contact-mail:hover { text-decoration: underline; }

/* ---------- 页脚 ---------- */
footer { border-top: 1px solid var(--border); padding: 28px 24px; text-align: center; color: var(--text-dim); font-size: 0.85rem; }
footer a { color: var(--text-dim); text-decoration: none; }
footer a:hover { color: var(--accent); }
footer .sep { margin: 0 10px; opacity: 0.5; }
.icp { display: inline-flex; align-items: center; gap: 5px; }
.icp-badge { flex: 0 0 auto; display: inline-block; vertical-align: -2px; }

/* ---------- 动效（仅 JS 可用时隐藏待显示元素） ---------- */
.js .reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
.js .reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { transition: none; opacity: 1; transform: none; }
  .card, .hero-cta, .nav { transition: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 640px) {
  .nav, .nav.scrolled { padding-left: 20px; padding-right: 20px; }
  .nav-links { gap: 18px; }
  section { padding: 72px 20px; }
}