:root {
  --accent: #089182;
  --accent-light: #16E0BD;
  --accent-dark: #0a3d38;
  --accent-soft: #e6faf6;
  --bg: #f6f9fb;
  --panel: #ffffff;
  --text: #16242b;
  --text-soft: #5b6b73;
  --border: #e2ebf0;
  --shadow: 0 6px 18px rgba(20, 60, 70, 0.08);
  --shadow-lg: 0 14px 38px rgba(20, 60, 70, 0.14);
  --radius: 14px;
  --maxw: 1200px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.mono { font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace; }

/* Nav */
nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 16px; color: var(--text); }
.brand .logo { width: 30px; height: 30px; border-radius: 8px; background: linear-gradient(135deg, var(--accent), var(--accent-light)); display: grid; place-items: center; color: #fff; font-size: 16px; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--text-soft); font-size: 14.5px; font-weight: 600; }
.nav-links a:hover { color: var(--accent); text-decoration: none; }
.nav-links a.active { color: var(--accent); }
.nav-cta { padding: 8px 18px; border-radius: 999px; background: var(--accent); color: #fff; font-weight: 700; font-size: 14px; }
.nav-cta:hover { background: var(--accent-dark); color: #fff; text-decoration: none; }
.nav-toggle { display: none; background: none; border: 0; font-size: 24px; cursor: pointer; color: var(--text); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 26px; border-radius: 999px; font-size: 15.5px; font-weight: 700;
  cursor: pointer; border: 2px solid transparent; transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover { transform: translateY(-2px); text-decoration: none; }
.btn-primary { background: #fff; color: var(--accent); box-shadow: 0 10px 26px rgba(0,0,0,.18); }
.btn-accent { background: var(--accent); color: #fff; box-shadow: var(--shadow); }
.btn-accent:hover { background: var(--accent-dark); color: #fff; }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.55); }
.btn-ghost:hover { background: rgba(255,255,255,.12); color: #fff; }
.btn-outline { background: #fff; color: var(--accent); border-color: var(--accent); }
.btn-outline:hover { background: var(--accent-soft); }
.btn-sm { padding: 9px 18px; font-size: 14px; }

/* Hero (home) */
.hero {
  background: linear-gradient(135deg, #0a3d38 0%, #089182 55%, #16E0BD 135%);
  color: #fff; padding: 60px 0 64px; text-align: center; position: relative; overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(circle at 18% 18%, rgba(255,255,255,.12), transparent 45%),
              radial-gradient(circle at 82% 72%, rgba(255,255,255,.10), transparent 42%);
  pointer-events: none;
}
.hero .container { position: relative; z-index: 1; }
.hero .badge { display: inline-block; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.3); border-radius: 999px; padding: 5px 16px; font-size: 13px; letter-spacing: .4px; margin-bottom: 16px; }
.hero h1 { font-size: 40px; line-height: 1.16; font-weight: 800; margin-bottom: 10px; }
.hero .tagline { font-size: 19px; opacity: .96; margin-bottom: 6px; }
.hero .sub { font-size: 15px; opacity: .82; margin-bottom: 24px; }
.hero .cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.trust { margin-top: 24px; display: flex; gap: 26px; justify-content: center; flex-wrap: wrap; opacity: .92; font-size: 14px; }
.trust b { font-size: 20px; display: block; font-weight: 800; }

/* Sub-page hero */
.subhero {
  background: linear-gradient(135deg, #0a3d38 0%, #089182 100%);
  color: #fff; padding: 40px 0 44px; text-align: center; position: relative; overflow: hidden;
}
.subhero .container { position: relative; z-index: 1; }
.subhero .crumbs { font-size: 13px; opacity: .8; margin-bottom: 10px; }
.subhero .crumbs a { color: var(--accent-light); }
.subhero h1 { font-size: 30px; font-weight: 800; margin-bottom: 8px; }
.subhero p { font-size: 15px; opacity: .88; max-width: 680px; margin: 0 auto; }

/* Sections */
section { padding: 40px 0; }
.section-head { text-align: center; margin-bottom: 28px; }
.section-head .eyebrow { color: var(--accent); font-weight: 700; font-size: 13px; letter-spacing: 1.5px; text-transform: uppercase; }
.section-head h2 { font-size: 26px; font-weight: 800; margin: 6px 0 8px; }
.section-head p { color: var(--text-soft); font-size: 15px; max-width: 640px; margin: 0 auto; }

/* Why cards */
.why-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.why { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 16px; box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease; }
.why:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.why .ico { width: 42px; height: 42px; border-radius: 12px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-size: 21px; margin-bottom: 10px; }
.why h3 { font-size: 15.5px; font-weight: 700; margin-bottom: 5px; }
.why p { color: var(--text-soft); font-size: 13.5px; }

/* Feature grid */
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 18px; box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.card .icon { font-size: 28px; line-height: 1; margin-bottom: 10px; display: block; }
.card h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 6px; }
.card p { color: var(--text-soft); font-size: 13.5px; }
.card .tags { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 6px; }
.card .tag { font-size: 11.5px; background: var(--accent-soft); color: var(--accent); padding: 3px 9px; border-radius: 999px; font-weight: 600; }
.more-link { display: inline-block; margin-top: 12px; font-size: 13.5px; font-weight: 700; }

/* Preview */
.preview-wrap { display: grid; grid-template-columns: 1.4fr 1fr; gap: 26px; align-items: center; }
.preview-frame { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); border: 1px solid var(--border); background: #0e1c22; }
.preview-frame svg { display: block; width: 100%; height: auto; }
.preview-copy h3 { font-size: 20px; font-weight: 800; margin-bottom: 12px; }
.preview-copy ul { list-style: none; }
.preview-copy li { padding: 7px 0 7px 26px; position: relative; color: var(--text-soft); font-size: 14px; border-bottom: 1px dashed var(--border); }
.preview-copy li:last-child { border-bottom: 0; }
.preview-copy li::before { content: "✓"; position: absolute; left: 0; top: 9px; color: var(--accent); font-weight: 800; }

/* UI 对比滑块：深色 / 浅色双主题 */
.cmp {
  position: relative; width: 100%; aspect-ratio: 960 / 560;
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-lg); border: 1px solid var(--border);
  background: #0b1418; touch-action: none; user-select: none; -webkit-user-select: none;
  cursor: ew-resize;
}
.cmp__layer { position: absolute; inset: 0; }
.cmp__layer svg { display: block; width: 100%; height: 100%; }
.cmp__dark { clip-path: inset(0 50% 0 0); }
.cmp__handle {
  position: absolute; top: 0; bottom: 0; left: 50%; width: 3px; margin-left: -1.5px;
  background: #fff; box-shadow: 0 0 0 1px rgba(0,0,0,.28); pointer-events: none; z-index: 3;
}
.cmp__grip {
  position: absolute; top: 50%; left: 50%; width: 44px; height: 44px;
  transform: translate(-50%,-50%); border-radius: 50%; background: #fff;
  box-shadow: 0 3px 10px rgba(0,0,0,.4); display: flex; align-items: center;
  justify-content: center; color: #0b1418; font-size: 17px; font-weight: 700; pointer-events: none;
}
.cmp__grip::before { content: "\21C4"; }
.cmp__badge {
  position: absolute; top: 14px; padding: 5px 12px; border-radius: 999px;
  font-size: 12.5px; font-weight: 700; letter-spacing: .3px; pointer-events: none; z-index: 4;
}
.cmp__badge--dark { left: 14px; background: rgba(11,20,24,.62); color: #e6edf3; }
.cmp__badge--light { right: 14px; background: rgba(245,247,250,.82); color: #1a1a2e; border: 1px solid rgba(0,0,0,.06); }
.cmp:focus-visible { outline: 3px solid var(--accent-light); outline-offset: 4px; }
.cmp__hint {
  position: absolute; bottom: 14px; left: 50%; transform: translateX(-50%);
  background: rgba(0,0,0,.55); color: #fff; font-size: 12px; padding: 5px 12px;
  border-radius: 999px; pointer-events: none; opacity: 0; transition: opacity .3s ease; z-index: 4;
}
.cmp:hover .cmp__hint, .cmp:focus-visible .cmp__hint { opacity: 1; }

/* Compare table */
.table-scroll { overflow-x: auto; border-radius: var(--radius); box-shadow: var(--shadow); border: 1px solid var(--border); }
table.cmp { width: 100%; border-collapse: collapse; min-width: 640px; background: var(--panel); }
table.cmp th, table.cmp td { padding: 13px 16px; text-align: center; font-size: 14px; border-bottom: 1px solid var(--border); }
table.cmp thead th { background: var(--accent-dark); color: #fff; font-weight: 700; position: sticky; top: 60px; }
table.cmp thead th:first-child { text-align: left; border-top-left-radius: var(--radius); }
table.cmp thead th:last-child { border-top-right-radius: var(--radius); }
table.cmp tbody th { text-align: left; font-weight: 600; color: var(--text); background: #fafdfc; }
table.cmp tbody tr:nth-child(even) td, table.cmp tbody tr:nth-child(even) th { background: #f7fbfa; }
.yes { color: var(--accent); font-weight: 800; font-size: 17px; }
.no { color: #c2ccd1; font-weight: 700; font-size: 15px; }
.col-ours { background: var(--accent-soft) !important; font-weight: 700; }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; counter-reset: step; }
.step { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 14px; box-shadow: var(--shadow); position: relative; }
.step .num { width: 34px; height: 34px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-weight: 800; font-size: 15px; margin-bottom: 10px; }
.step h3 { font-size: 14.5px; font-weight: 700; margin-bottom: 5px; }
.step p { color: var(--text-soft); font-size: 13px; }

/* Changelog timeline */
.timeline { max-width: 860px; margin: 0 auto; position: relative; padding-left: 22px; }
.timeline::before { content: ""; position: absolute; left: 5px; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.tl-item { position: relative; margin-bottom: 20px; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 20px; box-shadow: var(--shadow); }
.tl-item::before { content: ""; position: absolute; left: -22px; top: 22px; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); border: 3px solid #fff; box-shadow: 0 0 0 2px var(--accent); }
.tl-item .ver { font-weight: 800; font-size: 17px; color: var(--text); }
.tl-item .date { color: var(--text-soft); font-size: 12.5px; margin-left: 10px; }
.tl-item ul { margin: 8px 0 0; padding-left: 18px; color: var(--text-soft); font-size: 14px; }
.tl-item li { margin-bottom: 4px; }

/* Requirements */
.req-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.req { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; box-shadow: var(--shadow); text-align: center; }
.req .ico { font-size: 28px; margin-bottom: 8px; }
.req h3 { font-size: 15px; font-weight: 700; margin-bottom: 5px; }
.req p { color: var(--text-soft); font-size: 13.5px; }

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; }
details { background: var(--panel); border: 1px solid var(--border); border-radius: 12px; padding: 2px 18px; margin-bottom: 10px; box-shadow: var(--shadow); }
summary { cursor: pointer; font-weight: 600; font-size: 15px; padding: 12px 0; list-style: none; display: flex; justify-content: space-between; align-items: center; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "＋"; color: var(--accent); font-size: 20px; font-weight: 400; }
details[open] summary::after { content: "－"; }
details p { padding: 0 0 14px; color: var(--text-soft); font-size: 14px; }

/* Download */
.download { background: linear-gradient(135deg, #0a3d38 0%, #089182 100%); color: #fff; }
.dl-card { background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.22); border-radius: var(--radius); padding: 26px; text-align: center; max-width: 760px; margin: 0 auto; box-shadow: var(--shadow-lg); transition: transform .25s ease, box-shadow .25s ease; }
.dl-card:hover { transform: translateY(-4px); box-shadow: 0 22px 52px rgba(20,60,70,.18); }
.dl-tabs { display: inline-flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-bottom: 16px; }
.dl-tab { background: rgba(255,255,255,.10); border: 1px solid rgba(255,255,255,.35); border-radius: 999px; padding: 6px 14px; font-size: 13.5px; font-weight: 600; color: #fff; cursor: pointer; transition: background .15s, border-color .15s, color .15s, transform .15s; }
.dl-tab:hover { background: rgba(255,255,255,.18); transform: translateY(-1px); }
.dl-tab:focus-visible { outline: 2px solid #fff; outline-offset: 2px; }
.dl-tab.active { background: #fff; color: var(--accent); border-color: #fff; }
.dl-panels { position: relative; min-height: 165px; }
.dl-panel { display: none; }
.dl-panel.active { display: block; animation: fadeIn .25s ease; }
.dl-note { margin-top: 12px; font-size: 13.5px; opacity: .85; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.dl-card h2 { font-size: 22px; font-weight: 800; margin-bottom: 6px; }
.dl-card .meta { opacity: .85; font-size: 14px; margin-bottom: 16px; }
.dl-card .meta span { margin: 0 8px; }
.dl-card .hash { margin-top: 14px; font-size: 12px; opacity: .8; word-break: break-all; background: rgba(0,0,0,.18); padding: 8px 12px; border-radius: 10px; }
.dl-card .alt { margin-top: 14px; font-size: 13.5px; opacity: .9; }
.dl-card .alt a { color: var(--accent-light); }
.dl-card .btn-primary { background: #fff; color: var(--accent); }

/* CTA band */
.cta-band { text-align: center; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 20px; box-shadow: var(--shadow); }
.cta-band h2 { font-size: 22px; font-weight: 800; margin-bottom: 8px; }
.cta-band p { color: var(--text-soft); font-size: 14.5px; margin-bottom: 16px; }

/* Footer */
footer { background: #0c2a27; color: #cfe7e2; padding: 38px 0; text-align: center; font-size: 14px; }
footer a { color: var(--accent-light); }
footer .links { margin-bottom: 12px; display: flex; gap: 22px; justify-content: center; flex-wrap: wrap; }
footer .copy { opacity: .7; font-size: 13px; }

/* Reveal */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .55s ease, transform .55s ease; }
.reveal.in { opacity: 1; transform: none; }

/* Responsive */
@media (max-width: 980px) {
  .why-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .req-grid { grid-template-columns: repeat(2, 1fr); }
  .preview-wrap { grid-template-columns: 1fr; }
  .dl-card { max-width: 94%; }
}
@media (max-width: 760px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-links.open { display: flex; position: absolute; top: 60px; left: 0; right: 0; flex-direction: column; gap: 0; background: #fff; border-bottom: 1px solid var(--border); padding: 8px 20px 16px; }
  .nav-links.open a { padding: 12px 0; border-bottom: 1px solid var(--border); }
  .grid { grid-template-columns: 1fr; }
  .hero { padding: 46px 0 52px; }
  .hero h1 { font-size: 30px; }
  .hero .tagline { font-size: 17px; }
  section { padding: 32px 0; }
  .section-head { margin-bottom: 24px; }
  .section-head h2 { font-size: 23px; }
  .steps { grid-template-columns: 1fr; }
  .req-grid { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}