/* ============================================================
   Chivon — premium static site
   主题系统：CSS 变量 + [data-theme] 三态（light/dark/system）
   ============================================================ */

:root {
  --bg: #f7f7fb;
  --bg-elev: #ffffff;
  --surface: rgba(255, 255, 255, 0.6);
  --border: rgba(15, 18, 40, 0.08);
  --text: #14162b;
  --text-dim: #5a5f7a;
  --accent: #5b5bf0;
  --accent-2: #9b5bf0;
  --accent-soft: rgba(91, 91, 240, 0.12);
  --glow-1: rgba(91, 91, 240, 0.35);
  --glow-2: rgba(155, 91, 240, 0.30);
  --glow-3: rgba(70, 200, 200, 0.22);
  --shadow: 0 20px 50px -20px rgba(20, 22, 43, 0.25);
  --radius: 20px;
  --maxw: 1120px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
  --bg: #0a0b14;
  --bg-elev: #12141f;
  --surface: rgba(255, 255, 255, 0.04);
  --border: rgba(255, 255, 255, 0.09);
  --text: #f1f2f8;
  --text-dim: #a3a8c3;
  --accent: #8a8aff;
  --accent-2: #c08bff;
  --accent-soft: rgba(138, 138, 255, 0.16);
  --glow-1: rgba(138, 138, 255, 0.40);
  --glow-2: rgba(192, 139, 255, 0.34);
  --glow-3: rgba(80, 220, 220, 0.20);
  --shadow: 0 24px 60px -24px rgba(0, 0, 0, 0.7);
}

/* system → 跟随系统偏好 */
@media (prefers-color-scheme: dark) {
  [data-theme="system"] {
    --bg: #0a0b14;
    --bg-elev: #12141f;
    --surface: rgba(255, 255, 255, 0.04);
    --border: rgba(255, 255, 255, 0.09);
    --text: #f1f2f8;
    --text-dim: #a3a8c3;
    --accent: #8a8aff;
    --accent-2: #c08bff;
    --accent-soft: rgba(138, 138, 255, 0.16);
    --glow-1: rgba(138, 138, 255, 0.40);
    --glow-2: rgba(192, 139, 255, 0.34);
    --glow-3: rgba(80, 220, 220, 0.20);
    --shadow: 0 24px 60px -24px rgba(0, 0, 0, 0.7);
  }
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background-color 0.4s var(--ease), color 0.4s var(--ease);
}

a { color: inherit; text-decoration: none; }

/* ---------- Aurora 背景光晕 ---------- */
.aurora {
  position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none;
}
.aurora__blob {
  position: absolute; border-radius: 50%; filter: blur(80px); opacity: 0.7;
  animation: float 18s var(--ease) infinite alternate;
}
.aurora__blob--1 { width: 46vw; height: 46vw; left: -10vw; top: -12vw; background: var(--glow-1); }
.aurora__blob--2 { width: 40vw; height: 40vw; right: -8vw; top: 6vw; background: var(--glow-2); animation-delay: -6s; }
.aurora__blob--3 { width: 38vw; height: 38vw; left: 28vw; bottom: -16vw; background: var(--glow-3); animation-delay: -3s; }

@keyframes float {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(4vw, 3vw, 0) scale(1.15); }
}

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(18px) saturate(160%);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  transition: background-color 0.4s var(--ease);
}
.nav__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 1.15rem; letter-spacing: -0.02em; }
.brand__mark {
  display: grid; place-items: center; width: 30px; height: 30px; border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; font-size: 0.95rem;
}
.brand--sm { font-size: 1rem; }

.nav__links { display: flex; gap: 28px; }
.nav__links a {
  position: relative; color: var(--text-dim); font-size: 0.95rem; font-weight: 500;
  transition: color 0.25s var(--ease);
}
.nav__links a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: 2px;
  transition: width 0.3s var(--ease);
}
.nav__links a:hover { color: var(--text); }
.nav__links a:hover::after { width: 100%; }

.nav__actions { display: flex; align-items: center; gap: 10px; }

.theme-toggle {
  width: 38px; height: 38px; border-radius: 11px; border: 1px solid var(--border);
  background: var(--bg-elev); color: var(--text); cursor: pointer; display: grid; place-items: center;
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease);
}
.theme-toggle:hover { transform: rotate(-12deg) scale(1.05); border-color: var(--accent); }
.theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  [data-theme="system"] .theme-toggle .icon-sun { display: none; }
  [data-theme="system"] .theme-toggle .icon-moon { display: block; }
}

.nav__burger { display: none; flex-direction: column; gap: 5px; width: 38px; height: 38px;
  border-radius: 11px; border: 1px solid var(--border); background: var(--bg-elev); cursor: pointer; place-items: center; }
.nav__burger span { width: 18px; height: 2px; background: var(--text); border-radius: 2px; transition: 0.3s var(--ease); }
.nav__burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 通用 ---------- */
.eyebrow {
  display: inline-block; font-size: 0.8rem; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 14px;
}
.gradient-text {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.glass {
  background: var(--surface); backdrop-filter: blur(22px) saturate(160%);
  border: 1px solid var(--border); border-radius: var(--radius);
}
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 24px; border-radius: 13px; font-weight: 600; font-size: 0.95rem;
  border: 1px solid transparent; cursor: pointer; will-change: transform;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease);
}
.btn--primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; box-shadow: 0 12px 30px -12px var(--glow-1); }
.btn--primary:hover { box-shadow: 0 18px 40px -12px var(--glow-1); }
.btn--ghost { background: var(--bg-elev); color: var(--text); border-color: var(--border); }
.btn--ghost:hover { border-color: var(--accent); }

.section { max-width: var(--maxw); margin: 0 auto; padding: 100px 24px; }
.section__head { max-width: 640px; margin-bottom: 48px; }
.section__title { font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 700; letter-spacing: -0.03em; line-height: 1.15; }
.section__desc { color: var(--text-dim); margin-top: 14px; font-size: 1.05rem; }

/* ---------- Hero ---------- */
.hero { max-width: var(--maxw); margin: 0 auto; padding: 120px 24px 80px; }
.hero__content { max-width: 760px; }
.hero__title { font-size: clamp(2.4rem, 6vw, 4.2rem); font-weight: 800; letter-spacing: -0.04em; line-height: 1.08; }
.hero__sub { color: var(--text-dim); font-size: clamp(1.05rem, 2vw, 1.25rem); margin-top: 22px; max-width: 620px; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 34px; }
.hero__stats { display: flex; gap: 40px; margin-top: 56px; flex-wrap: wrap; }
.stat b { display: block; font-size: 2.2rem; font-weight: 800; letter-spacing: -0.03em;
  background: linear-gradient(120deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { color: var(--text-dim); font-size: 0.9rem; }

/* ---------- 项目网格 ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 22px; }
.card {
  position: relative; padding: 26px; border-radius: var(--radius); background: var(--bg-elev);
  border: 1px solid var(--border); box-shadow: var(--shadow); overflow: hidden;
  transition: transform 0.35s var(--ease), border-color 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.card::before {
  content: ""; position: absolute; inset: 0; border-radius: inherit; padding: 1px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude; opacity: 0; transition: opacity 0.35s var(--ease);
}
.card:hover { transform: translateY(-6px); box-shadow: 0 30px 60px -24px var(--glow-1); }
.card:hover::before { opacity: 1; }
.card__top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.card__icon { font-size: 1.8rem; color: var(--accent); }
.card__title { font-size: 1.25rem; font-weight: 700; letter-spacing: -0.02em; }
.card__desc { color: var(--text-dim); margin-top: 10px; font-size: 0.96rem; }
.card__link { display: inline-block; margin-top: 18px; color: var(--accent); font-weight: 600; font-size: 0.92rem; }
.card--add { border-style: dashed; background: var(--surface); display: flex; flex-direction: column; }

.tag { font-size: 0.72rem; font-weight: 700; letter-spacing: 0.06em; padding: 4px 10px; border-radius: 999px; }
.tag--live { background: var(--accent-soft); color: var(--accent); }
.tag--soon { background: rgba(255, 170, 80, 0.16); color: #d98a2b; }

/* ---------- 关于 ---------- */
.section--about { padding-top: 40px; }
.about { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 40px; align-items: center; }
.about__text p { color: var(--text-dim); margin-top: 16px; font-size: 1.05rem; }
.about__list { list-style: none; margin-top: 22px; display: grid; gap: 12px; }
.about__list li { position: relative; padding-left: 26px; color: var(--text); font-weight: 500; }
.about__list li::before {
  content: "✶"; position: absolute; left: 0; top: 0; color: var(--accent); font-size: 0.9rem;
}
.about__panel { padding: 28px; }
.about__row { display: flex; justify-content: space-between; gap: 12px; padding: 14px 0; border-bottom: 1px solid var(--border); }
.about__row:last-child { border-bottom: none; }
.about__row span { color: var(--text-dim); font-size: 0.92rem; }
.about__row b { font-weight: 600; text-align: right; }

/* ---------- 联系 ---------- */
.contact { padding: 48px; text-align: center; }
.contact .section__desc { max-width: 460px; margin-left: auto; margin-right: auto; }
.contact__form { max-width: 480px; margin: 28px auto 0; display: grid; gap: 14px; }
.contact__form input, .contact__form textarea {
  width: 100%; padding: 14px 16px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); font-size: 0.98rem; font-family: inherit; resize: vertical;
  transition: border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
.contact__form input:focus, .contact__form textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft);
}
.contact__form .btn { width: 100%; }
.contact__hint { font-size: 0.9rem; min-height: 1.2em; color: var(--accent); }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--border); background: var(--surface); }
.footer__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 28px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.footer__copy { color: var(--text-dim); font-size: 0.9rem; }
.footer__links { display: flex; gap: 22px; }
.footer__links a { color: var(--text-dim); font-size: 0.9rem; transition: color 0.25s var(--ease); }
.footer__links a:hover { color: var(--text); }
.footer__beian { flex-basis: 100%; display: flex; gap: 0.75rem; flex-wrap: wrap; margin-top: 4px; font-size: 0.78rem; opacity: 0.6; }
.footer__beian a { color: var(--text-dim); text-decoration: none; }
.footer__beian a:hover { color: var(--text); opacity: 1; }

/* ---------- 滚动揭示动画 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 820px) {
  .about { grid-template-columns: 1fr; }
  .nav__links {
    position: fixed; inset: 64px 0 auto 0; flex-direction: column; gap: 0;
    background: var(--bg-elev); border-bottom: 1px solid var(--border); padding: 8px 0;
    transform: translateY(-130%); transition: transform 0.35s var(--ease); z-index: 40;
  }
  .nav__links.is-open { transform: translateY(0); }
  .nav__links a { padding: 14px 24px; }
  .nav__links a::after { display: none; }
  .nav__burger { display: grid; }
  .section { padding: 72px 20px; }
  .hero { padding: 90px 20px 60px; }
}

@media (prefers-reduced-motion: reduce) {
  .aurora__blob { animation: none; }
  .reveal { transition: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}