/* 豆芽便签官网：和 App 同一套视觉——暖白纸 + 淡点阵（深色是暖黑），钢笔线稿，荧光绿只当荧光笔用 */
:root {
  --paper: #FAF8F2;
  --paper-2: #F3F0E6;
  --card: #FFFEFB;
  --ink: #1C1B17;
  --title: #14130F;
  --text2: #3E3B33;
  --muted: #6E6A5E;
  --dot: rgba(120, 105, 70, 0.13);
  --line: rgba(58, 52, 32, 0.12);
  --soft: rgba(58, 52, 32, 0.05);
  --acc: #C8F031;
  --acc-ink: #4A6B00;
  --mark: rgba(200, 240, 49, 0.75);
  --art: rgba(20, 19, 15, 0.78);
  --art-fill: rgba(200, 240, 49, 0.55);
  --btn: #14130F;
  --btn-fg: #FAF8F2;
  --shadow: 0 18px 50px rgba(40, 34, 18, 0.12), 0 2px 6px rgba(40, 34, 18, 0.06);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #131311; --paper-2: #191916; --card: #1A1A17; --ink: #EDECE6; --title: #F5F4EF; --text2: #C9C7BF; --muted: #8C897E;
    --dot: rgba(255, 255, 255, 0.05); --line: rgba(255, 255, 255, 0.1); --soft: rgba(255, 255, 255, 0.05);
    --acc-ink: #C8F031; --mark: rgba(200, 240, 49, 0.4); --art: rgba(245, 244, 239, 0.7); --art-fill: rgba(200, 240, 49, 0.3);
    --btn: #C8F031; --btn-fg: #131311; --shadow: 0 18px 50px rgba(0, 0, 0, 0.5);
  }
}
:root[data-theme="dark"] {
  --paper: #131311; --paper-2: #191916; --card: #1A1A17; --ink: #EDECE6; --title: #F5F4EF; --text2: #C9C7BF; --muted: #8C897E;
  --dot: rgba(255, 255, 255, 0.05); --line: rgba(255, 255, 255, 0.1); --soft: rgba(255, 255, 255, 0.05);
  --acc-ink: #C8F031; --mark: rgba(200, 240, 49, 0.4); --art: rgba(245, 244, 239, 0.7); --art-fill: rgba(200, 240, 49, 0.3);
  --btn: #C8F031; --btn-fg: #131311; --shadow: 0 18px 50px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  background-image: radial-gradient(var(--dot) 1px, transparent 1.2px);
  background-size: 22px 22px;
  color: var(--ink);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 24px; }
@media (max-width: 600px) { .wrap { padding: 0 16px; } }

/* 荧光笔：只划在关键词下半截 */
.mark { background: linear-gradient(transparent 58%, var(--mark) 58%, var(--mark) 92%, transparent 92%); padding: 0 .08em; }

.pen { color: var(--art); display: block; }

/* 顶栏 */
header.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; gap: 20px; height: 60px; }
.brand { display: flex; align-items: center; gap: 8px; white-space: nowrap; text-decoration: none; font-weight: 650; color: var(--title); letter-spacing: .02em; }
.brand svg { width: 22px; height: 24px; color: var(--title); }
header.top nav { margin-left: auto; display: flex; gap: 22px; align-items: center; font-size: 14.5px; }
header.top nav a { text-decoration: none; color: var(--text2); }
header.top nav a:hover { color: var(--title); }
header.top nav a.btn, header.top nav a.btn:hover { color: var(--btn-fg); }
@media (max-width: 600px) { header.top nav a.hide-sm { display: none; } header.top nav { gap: 14px; } }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: 999px; background: var(--btn); color: var(--btn-fg); text-decoration: none; font-weight: 600; font-size: 15px; border: 0; cursor: pointer; }
.btn:hover { filter: brightness(1.08); }
.btn.small { padding: 7px 14px; font-size: 13.5px; }
.btn.ghost { background: transparent; color: var(--title); border: 1px solid var(--line); }
kbd { font: 600 12.5px/1 ui-monospace, SFMono-Regular, Menlo, monospace; padding: 4px 7px; border-radius: 6px; border: 1px solid var(--line); background: var(--soft); color: var(--text2); }

/* 首屏 */
.hero { padding-top: 72px; padding-bottom: 40px; display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.hero h1 { font-size: clamp(38px, 6vw, 64px); line-height: 1.12; margin: 18px 0 16px; color: var(--title); letter-spacing: .01em; font-weight: 700; }
.hero p.lead { font-size: 18px; color: var(--text2); margin: 0 0 28px; max-width: 30em; }
.hero .cta { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.hero .fine { font-size: 13px; color: var(--muted); margin-top: 14px; }
.hero .art { width: 92px; height: 98px; }
@media (max-width: 820px) { .hero { grid-template-columns: 1fr; padding-top: 40px; } }
.hero > * { min-width: 0; }

/* 面板示意：一张便签 */
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow); overflow: hidden; }
.panel .bar { display: flex; align-items: center; gap: 8px; padding: 12px 16px; border-bottom: 1px solid var(--line); font-size: 13px; color: var(--muted); }
.panel .bar svg { width: 15px; height: 16px; color: var(--title); }
.panel .bar b { color: var(--title); font-weight: 600; }
.panel .bar .sprouts { margin-left: auto; letter-spacing: 2px; }
.panel .body { padding: 18px 22px 22px; font-size: 15px; }
.panel h3 { margin: 0 0 8px; font-size: 18px; color: var(--title); }
.panel ul { padding-left: 1.2em; margin: 6px 0; }
.panel .todo { list-style: none; padding-left: 0; }
.panel .todo li::before { content: ""; display: inline-block; width: 13px; height: 13px; border: 1.5px solid var(--muted); border-radius: 4px; margin-right: 8px; vertical-align: -1px; }
.panel .todo li.done { color: var(--muted); text-decoration: line-through; }
.panel .todo li.done::before { background: var(--acc); border-color: var(--acc); }
.panel .hint { margin-top: 14px; font-size: 12.5px; color: var(--muted); display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

/* 段落 */
section { padding: 56px 0; }
section h2 { font-size: clamp(26px, 3.6vw, 34px); margin: 0 0 10px; color: var(--title); }
section .sub { color: var(--text2); margin: 0 0 32px; max-width: 36em; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 900px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .grid { grid-template-columns: 1fr; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 22px; }
.card h3 { margin: 0 0 6px; font-size: 17px; color: var(--title); }
.card p { margin: 0; color: var(--text2); font-size: 14.5px; }
.card .ico { font-size: 13px; font-weight: 700; color: var(--acc-ink); letter-spacing: .08em; margin-bottom: 10px; }

.free { text-align: center; padding-top: 48px; padding-bottom: 48px; }
.free p { font-size: clamp(20px, 3vw, 26px); color: var(--title); margin: 0; font-weight: 600; }
.free small { display: block; color: var(--muted); margin-top: 8px; font-size: 14px; font-weight: 400; }

/* 价格 */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; align-items: stretch; }
@media (max-width: 900px) { .plans { grid-template-columns: 1fr; } }
.plan { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 26px; display: flex; flex-direction: column; }
.plan.pick { border-color: var(--acc-ink); box-shadow: 0 0 0 3px color-mix(in srgb, var(--acc) 35%, transparent); }
.plan h3 { margin: 0; font-size: 18px; color: var(--title); }
.plan .price { font-size: 30px; font-weight: 700; color: var(--title); margin: 12px 0 2px; }
.plan .price small { font-size: 14px; color: var(--muted); font-weight: 500; }
.plan .per { font-size: 13px; color: var(--muted); min-height: 1.6em; }
.plan ul { list-style: none; padding: 0; margin: 18px 0 22px; font-size: 14.5px; color: var(--text2); flex: 1; }
.plan li { padding: 5px 0 5px 24px; position: relative; }
.plan li::before { content: ""; position: absolute; left: 2px; top: 12px; width: 12px; height: 6px; border-left: 2px solid var(--acc-ink); border-bottom: 2px solid var(--acc-ink); transform: rotate(-45deg); }
.plan .note { font-size: 12.5px; color: var(--muted); margin-top: 10px; }
.billing { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 3px; margin-bottom: 22px; background: var(--card); }
.billing button { border: 0; background: transparent; color: var(--text2); padding: 6px 14px; border-radius: 999px; font: inherit; font-size: 14px; cursor: pointer; }
.billing button[aria-pressed="true"] { background: var(--btn); color: var(--btn-fg); }

/* 问答 */
details { border-top: 1px solid var(--line); padding: 14px 0; }
details:last-child { border-bottom: 1px solid var(--line); }
summary { cursor: pointer; font-weight: 600; color: var(--title); list-style: none; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; float: right; color: var(--muted); font-weight: 400; }
details[open] summary::after { content: "–"; }
details p { color: var(--text2); margin: 8px 0 0; }

footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 13.5px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 18px; align-items: center; }
footer nav { display: flex; gap: 16px; flex-wrap: wrap; }
footer a { text-decoration: none; }
footer a:hover { color: var(--title); }
footer .right { margin-left: auto; }

/* 条款类长文 */
.doc { max-width: 760px; padding-top: 48px; padding-bottom: 72px; }
.doc h1 { font-size: 32px; color: var(--title); margin: 0 0 6px; }
.doc .meta { color: var(--muted); font-size: 14px; margin-bottom: 28px; }
.doc h2 { font-size: 20px; color: var(--title); margin: 32px 0 8px; }
.doc p, .doc li { color: var(--text2); }
.doc table { border-collapse: collapse; width: 100%; font-size: 14.5px; margin: 10px 0; }
.doc th, .doc td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; color: var(--text2); }
.doc th { background: var(--soft); color: var(--title); }
.todo-fill { background: var(--mark); padding: 0 .2em; border-radius: 3px; }

/* 付款页 */
.center { min-height: 70vh; display: grid; place-items: center; text-align: center; padding-top: 40px; padding-bottom: 40px; }
.center .art { width: 72px; height: 77px; margin: 0 auto 18px; }
.center h1 { font-size: 26px; color: var(--title); margin: 0 0 8px; }
.center p { color: var(--text2); margin: 0 auto; max-width: 28em; }