/* ============================================================
   轻匣 · 官网样式  —— 深色简约科技风，无任何外部依赖
   ============================================================ */

:root {
  --bg: #080c0c;
  --bg-alt: #0c1212;
  --card: rgba(255, 255, 255, 0.028);
  --card-hover: rgba(46, 224, 192, 0.06);
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(46, 224, 192, 0.35);
  --text: #e7efee;
  --muted: #8b9997;
  --accent: #2ee0c0;
  --accent-deep: #0b8b85;
  --accent-ink: #05201c;
  --glow: rgba(46, 224, 192, 0.16);
  --radius: 16px;
  --maxw: 1080px;
  --nav-h: 64px;
}

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

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 顶部细网格底纹 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 30%, transparent 75%);
}

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- 通用排版 ---------- */
.eyebrow {
  font-size: 12px;
  letter-spacing: 0.28em;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 14px;
}

.section { padding: 96px 0; position: relative; }
.section--alt { background: var(--bg-alt); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section__head { text-align: center; margin-bottom: 56px; }
.section__title {
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1.3;
}
.section__sub { color: var(--muted); margin-top: 12px; }

.accent {
  background: linear-gradient(120deg, var(--accent), var(--accent-deep));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 999px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn--sm { padding: 8px 18px; font-size: 14px; color: var(--accent-ink); background: var(--accent); }
.btn--lg { padding: 14px 30px; font-size: 16px; }
.btn--xl { padding: 17px 38px; font-size: 17px; }

.btn:not(.btn--ghost) {
  color: var(--accent-ink);
  background: linear-gradient(120deg, var(--accent), var(--accent-deep));
}
.btn--glow { box-shadow: 0 6px 28px var(--glow); }

.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 36px rgba(46,224,192,.28); }
.btn:active { transform: translateY(0); }

.btn--ghost {
  color: var(--text);
  background: transparent;
  border-color: var(--line);
}
.btn--ghost:hover { border-color: var(--line-strong); background: var(--card-hover); box-shadow: none; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 50;
  transition: background .25s ease, border-color .25s ease, backdrop-filter .25s ease;
  border-bottom: 1px solid transparent;
}
.nav.is-scrolled {
  background: rgba(8, 12, 12, 0.78);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom-color: var(--line);
}
.nav__inner { height: 100%; display: flex; align-items: center; gap: 32px; }

.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand__img {
  width: 32px; height: 32px;
  border-radius: 9px;
  border: 1px solid var(--line);
  box-shadow: 0 2px 12px var(--glow);
  display: block;
}
.footer__img {
  width: 24px; height: 24px;
  border-radius: 7px;
  border: 1px solid var(--line);
  display: block;
}
.brand__name { font-size: 19px; font-weight: 700; letter-spacing: .08em; color: var(--text); }

.nav__links { display: flex; gap: 28px; margin-left: auto; }
.nav__links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 15px;
  transition: color .2s ease;
}
.nav__links a:hover { color: var(--text); }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + 92px) 0 96px; text-align: center; }
.hero__glow {
  position: absolute;
  top: -180px; left: 50%;
  width: 720px; height: 520px;
  transform: translateX(-50%);
  background: radial-gradient(ellipse at center, var(--glow), transparent 65%);
  pointer-events: none;
}
.hero__inner { position: relative; }
.hero__title {
  font-size: clamp(34px, 6.4vw, 58px);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: 0.01em;
}
.hero__desc {
  max-width: 620px;
  margin: 24px auto 0;
  color: var(--muted);
  font-size: 17px;
}
.hero__actions { margin-top: 36px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero__meta {
  margin-top: 30px;
  list-style: none;
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}
.hero__meta li {
  font-size: 13px;
  color: var(--muted);
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 5px 14px;
}
.hero__meta li.dot::before { content: ""; display: inline-block; width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent); margin-right: 8px; vertical-align: 2px; }

/* ---------- 功能卡片 ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.card {
  position: relative;
  padding: 32px 28px;
  border-radius: var(--radius);
  background: var(--card);
  border: 1px solid var(--line);
  transition: transform .25s ease, border-color .25s ease, background .25s ease;
  overflow: hidden;
}
.card::after {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(420px circle at var(--mx, 50%) 0%, rgba(46,224,192,.10), transparent 60%);
  opacity: 0;
  transition: opacity .3s ease;
  pointer-events: none;
}
.card:hover { transform: translateY(-5px); border-color: var(--line-strong); background: var(--card-hover); }
.card:hover::after { opacity: 1; }
.card__icon {
  width: 46px; height: 46px;
  display: grid; place-items: center;
  border-radius: 12px;
  color: var(--accent);
  background: rgba(46,224,192,.10);
  border: 1px solid rgba(46,224,192,.22);
  margin-bottom: 20px;
}
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

/* ---------- 优势 ---------- */
.advantages {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px 28px;
  max-width: 860px;
  margin: 0 auto;
}
.adv { display: flex; gap: 18px; align-items: flex-start; }
.adv__icon {
  flex: 0 0 auto;
  width: 42px; height: 42px;
  display: grid; place-items: center;
  border-radius: 50%;
  color: var(--accent);
  background: rgba(46,224,192,.10);
  border: 1px solid rgba(46,224,192,.22);
}
.adv h3 { font-size: 17px; margin-bottom: 4px; }
.adv p { color: var(--muted); font-size: 15px; }

/* ---------- 下载面板 ---------- */
.download {
  position: relative;
  border-radius: 24px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(46,224,192,.06), rgba(255,255,255,.02));
  padding: 64px 32px;
  text-align: center;
  overflow: hidden;
}
.download__glow {
  position: absolute;
  bottom: -240px; left: 50%;
  width: 600px; height: 420px;
  transform: translateX(-50%);
  background: radial-gradient(ellipse at center, var(--glow), transparent 65%);
  pointer-events: none;
}
.download__body { position: relative; }
.download .btn { margin-top: 28px; }

.dl {
  margin: 34px auto 0;
  max-width: 560px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
.dl > div {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 8px;
  background: rgba(0,0,0,.18);
}
.dl dt { font-size: 12px; color: var(--muted); }
.dl dd { font-size: 14px; font-weight: 600; margin-top: 2px; }

.changelog { margin-top: 36px; text-align: left; max-width: 560px; margin-left: auto; margin-right: auto; }
.changelog h3 { font-size: 14px; color: var(--muted); font-weight: 600; margin-bottom: 8px; letter-spacing: .06em; }
.changelog ul { list-style: none; }
.changelog li {
  position: relative;
  padding-left: 18px;
  color: var(--muted);
  font-size: 14px;
  line-height: 2;
}
.changelog li::before {
  content: "";
  position: absolute;
  left: 0; top: 13px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-deep);
}

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--line); padding: 28px 0; }

/* 作者另一款作品：快图 */
.more-link {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
  padding: 16px 20px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--card);
  text-decoration: none;
  transition: border-color .2s ease, background .2s ease, transform .2s ease;
}
.more-link:hover {
  border-color: var(--line-strong);
  background: var(--card-hover);
  transform: translateY(-1px);
}
.more-link__tag {
  flex: 0 0 auto;
  font-size: 12px;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 3px 12px;
  white-space: nowrap;
}
.more-link__main { display: flex; align-items: baseline; gap: 10px; flex: 1; min-width: 0; }
.more-link__name { font-size: 15px; font-weight: 700; color: var(--text); white-space: nowrap; }
.more-link__desc {
  font-size: 13px;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.more-link__arrow { flex: 0 0 auto; color: var(--muted); transition: color .2s ease, transform .2s ease; }
.more-link:hover .more-link__arrow { color: var(--accent); transform: translate(2px, -2px); }

.footer__inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.footer__brand { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: 14px; }
.footer p { color: var(--muted); font-size: 13px; }

/* ---------- 入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-in { opacity: 1; transform: none; }

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

/* ---------- 响应式 ---------- */
@media (max-width: 860px) {
  .cards { grid-template-columns: 1fr; }
  .advantages { grid-template-columns: 1fr; }
  .section { padding: 72px 0; }
}
@media (max-width: 560px) {
  .nav__links { display: none; }
  .hero { padding-top: calc(var(--nav-h) + 60px); }
  .dl { grid-template-columns: repeat(2, 1fr); }
  .download { padding: 48px 20px; }
  .footer__inner { justify-content: center; text-align: center; }
  .more-link { position: relative; flex-wrap: wrap; gap: 8px 12px; padding: 14px 16px 14px 44px; }
  .more-link__main { flex-basis: 100%; flex-wrap: wrap; gap: 4px 10px; }
  .more-link__desc { white-space: normal; }
  .more-link__arrow { position: absolute; top: 18px; right: 16px; }
}