:root {
  --paper: #f7f5f0;
  --card: #ffffff;
  --ink: #1f2420;
  --muted: #6b7370;
  --line: #e4e0d8;
  --accent: #296e61;
  --accent-soft: #e3efeb;
  --accent-ink: #1d5449;
  --warn: #8a5a1a;
  --warn-soft: #f6ecd9;
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "Georgia", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Helvetica Neue", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", Menlo, Consolas, monospace;
  --max: 1040px;
}
@media (prefers-color-scheme: dark) {
  :root { --paper: #15181a; --card: #1d2124; --ink: #ebe8e1; --muted: #9aa39f; --line: #2c3236; --accent: #6cb8a7; --accent-soft: #1f3530; --accent-ink: #9ed6c8; --warn: #d9a75a; --warn-soft: #3a2f1c; }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
html, body { overflow-x: hidden; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 17px; line-height: 1.75; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
img { max-width: 100%; display: block; }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; letter-spacing: 0.01em; margin: 0 0 0.5em; }
h1 { font-size: clamp(2rem, 5vw, 3.1rem); }
h2 { font-size: clamp(1.5rem, 3.2vw, 2.1rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em; }
.muted { color: var(--muted); }
.small { font-size: 0.92rem; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: 760px; }
code, kbd { font-family: var(--mono); font-size: 0.9em; }
kbd { background: var(--card); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 6px; padding: 1px 7px; }
pre { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; overflow-x: auto; font-size: 0.9rem; }

/* 顶栏 */
.nav { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: saturate(140%) blur(12px); border-bottom: 1px solid var(--line); }
.nav .wrap { display: flex; align-items: center; gap: 22px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-family: var(--serif); font-size: 1.35rem; font-weight: 600; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.nav-links { display: flex; gap: 20px; margin-left: auto; font-size: 0.95rem; }
.nav-links a { color: var(--muted); }
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav .btn { margin-left: 8px; }
@media (max-width: 720px) { .nav-links a:not(.keep) { display: none; } }

/* 按钮 */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 10px; font-weight: 600; font-size: 0.98rem; border: 1px solid var(--accent); background: var(--accent); color: #fff; cursor: pointer; font-family: var(--sans); line-height: 1.2; transition: transform .08s ease, opacity .15s ease; }
.btn:hover { text-decoration: none; opacity: 0.92; transform: translateY(-1px); }
.btn.secondary { background: transparent; color: var(--accent); }
.btn.large { padding: 14px 26px; font-size: 1.05rem; }
.btn[disabled] { opacity: 0.6; cursor: wait; transform: none; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

/* Hero */
.hero { padding: 72px 0 40px; }
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 48px; align-items: center; }
@media (max-width: 860px) { .hero-grid { grid-template-columns: 1fr; } }
.eyebrow { display: inline-block; font-size: 0.85rem; letter-spacing: 0.08em; color: var(--accent); text-transform: uppercase; margin-bottom: 14px; font-weight: 600; }
.lede { font-size: 1.15rem; color: var(--muted); max-width: 560px; }
.meta { display: flex; flex-wrap: wrap; gap: 8px 18px; font-size: 0.9rem; color: var(--muted); margin-top: 18px; }
.meta span::before { content: "·"; margin-right: 8px; color: var(--line); }
.meta span:first-child::before { content: none; }

/* 浮窗示意 */
.panel-demo { display: grid; gap: 18px; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 18px 50px -30px rgba(0,0,0,0.35); padding: 16px 18px 14px; font-size: 0.95rem; }
.panel-head { display: flex; align-items: center; gap: 8px; font-family: var(--serif); font-weight: 600; font-size: 1.05rem; padding-bottom: 10px; border-bottom: 1px solid var(--line); margin-bottom: 12px; }
.panel-head img { width: 22px; height: 22px; border-radius: 6px; }
.panel-head .dots { margin-left: auto; display: flex; gap: 6px; }
.panel-head .dots i { width: 8px; height: 8px; border-radius: 50%; background: var(--line); display: block; }
.panel .lang { font-size: 0.75rem; color: var(--muted); font-weight: 600; }
.panel .orig { font-family: var(--serif); color: var(--muted); margin: 4px 0 8px; }
.panel .orig.big { font-size: 2rem; color: var(--ink); font-weight: 500; line-height: 1.2; }
.panel .trans { font-size: 1.3rem; font-weight: 600; line-height: 1.4; }
.panel .pinyin { font-size: 1.5rem; color: var(--accent); font-weight: 600; letter-spacing: 0.02em; }
.panel .src { font-size: 0.75rem; color: var(--muted); margin-top: 8px; }
.panel .foot { display: flex; gap: 14px; font-size: 0.8rem; color: var(--muted); border-top: 1px solid var(--line); margin-top: 12px; padding-top: 10px; }

/* 区块 */
section { padding: 56px 0; }
section.alt { background: var(--card); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 640px; margin-bottom: 32px; }
.section-head p { color: var(--muted); font-size: 1.05rem; }
.grid { display: grid; gap: 20px; }
.grid.three { grid-template-columns: repeat(3, 1fr); }
.grid.two { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 860px) { .grid.three, .grid.two { grid-template-columns: 1fr; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 24px; }
section.alt .card { background: var(--paper); }
.card h3 { margin-bottom: 8px; }
.card p:last-child { margin-bottom: 0; }
.card .tag { display: inline-block; font-size: 0.78rem; color: var(--accent-ink); background: var(--accent-soft); border-radius: 999px; padding: 2px 10px; margin-bottom: 10px; font-weight: 600; }
.feature-list { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px 28px; }
@media (max-width: 720px) { .feature-list { grid-template-columns: 1fr; } }
.feature-list li { padding-left: 26px; position: relative; }
.feature-list li::before { content: ""; position: absolute; left: 0; top: 0.55em; width: 12px; height: 12px; border-radius: 50%; background: var(--accent-soft); border: 2px solid var(--accent); }
.feature-list b { display: block; font-weight: 600; }
.feature-list span { color: var(--muted); font-size: 0.95rem; }

/* 步骤 */
.steps { counter-reset: step; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 860px) { .steps { grid-template-columns: 1fr; } }
.step { counter-increment: step; background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 24px; }
.step::before { content: counter(step); display: inline-flex; width: 32px; height: 32px; align-items: center; justify-content: center; border-radius: 50%; background: var(--accent); color: #fff; font-weight: 700; font-family: var(--serif); margin-bottom: 12px; }
section.alt .step { background: var(--paper); }

/* 定价 */
.price-card { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 32px; display: grid; grid-template-columns: 1fr 1fr; gap: 32px; align-items: start; }
@media (max-width: 860px) { .price-card { grid-template-columns: 1fr; } }
.price { font-family: var(--serif); font-size: 3rem; font-weight: 600; line-height: 1; }
.price small { font-size: 1rem; color: var(--muted); font-family: var(--sans); font-weight: 500; margin-left: 8px; }
.check-list { list-style: none; padding: 0; margin: 0 0 18px; }
.check-list li { padding-left: 26px; position: relative; margin-bottom: 8px; }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
.timeline { display: grid; gap: 8px; margin: 0 0 22px; }
.timeline div { display: flex; gap: 14px; align-items: baseline; background: var(--paper); border: 1px solid var(--line); border-radius: 10px; padding: 10px 14px; font-size: 0.95rem; }
.timeline b { flex: 0 0 7.5em; font-size: 0.95rem; color: var(--accent-ink); }
section.alt .timeline div { background: var(--card); }
.notice { border-left: 3px solid var(--accent); background: var(--accent-soft); color: var(--accent-ink); padding: 12px 16px; border-radius: 0 10px 10px 0; font-size: 0.95rem; }
.notice.warn { border-color: var(--warn); background: var(--warn-soft); color: var(--warn); }

/* FAQ */
.faq details { border-bottom: 1px solid var(--line); padding: 16px 0; }
.faq summary { cursor: pointer; font-weight: 600; font-size: 1.05rem; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; flex: none; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin: 12px 0 0; color: var(--muted); }
.faq details p:last-child { margin-bottom: 0; }
.faq h3 { margin-top: 36px; }

/* 文档页 */
.doc { padding: 56px 0 72px; }
.doc h1 { margin-bottom: 0.3em; }
.doc h2 { margin-top: 2em; font-size: 1.5rem; }
.doc h3 { margin-top: 1.6em; }
.doc ol, .doc ul { padding-left: 1.4em; }
.doc li { margin-bottom: 0.4em; }
.doc .lede { margin-bottom: 28px; }
.doc table { border-collapse: collapse; width: 100%; font-size: 0.95rem; display: block; overflow-x: auto; }
.doc table tbody { display: table; width: 100%; min-width: 520px; }
.doc th, .doc td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.doc th { color: var(--muted); font-weight: 600; }

/* 表单与授权码 */
.field { display: flex; gap: 10px; flex-wrap: wrap; }
.field input { flex: 1 1 260px; font: inherit; padding: 11px 14px; border: 1px solid var(--line); border-radius: 10px; background: var(--card); color: var(--ink); }
.field input:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.license-box { font-family: var(--mono); font-size: 0.95rem; line-height: 1.6; word-break: break-all; background: var(--card); border: 1px dashed var(--accent); border-radius: 12px; padding: 16px 18px; user-select: all; }
.status { min-height: 1.5em; font-size: 0.95rem; color: var(--muted); }
.status.error { color: #a23b2f; }

/* 页脚 */
footer { border-top: 1px solid var(--line); padding: 36px 0 48px; font-size: 0.9rem; color: var(--muted); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center; }
footer a { color: var(--muted); }
footer .spacer { flex: 1; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 8px; background: var(--card); padding: 8px 12px; border-radius: 8px; z-index: 99; }