/*
 * 课思悠 · 引导式承接页样式（Lead-you-through 模板 v1，2026-09-19）
 * 锚点：Swiss（继承 design-system/classyoo-seo-landing/MASTER.md）
 * 单一强调色 #196BD7，1px 细线，无阴影，系统中文栈，等宽数字。
 * 本文件只服务新模板页；老的 seo-landing.css 保持不动。
 */

:root {
  --ink: #172B3A;
  --ink-2: #4C5E71;
  --ink-3: #5B6B7C;
  --line: #DCE4ED;
  --line-soft: #EEF2F7;
  --brand: #196BD7;
  --brand-deep: #0F4FA8;
  --brand-tint: #F1F6FD;
  --bg: #FFFFFF;
  --bg-soft: #F7F8FA;
  --r-shot: 12px;
  --r-card: 14px;
  --max: 1120px;
  --rail: 208px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  font-variant-numeric: tabular-nums;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 3px; }

.g-top {
  position: sticky; top: 0; z-index: 30;
  background: rgba(255, 255, 255, .96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(1.2) blur(6px);
}
.g-top__inner {
  max-width: var(--max); margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
}
.g-brand { font-weight: 700; font-size: 16px; color: var(--ink); }
.g-brand span { color: var(--brand); }
.g-top__nav { margin-left: auto; display: flex; gap: 16px; font-size: 14px; flex-wrap: wrap; align-items: center; }
.g-top__nav a { color: var(--ink-2); }
.g-top__nav a:hover { color: var(--brand); }
.g-top__cta { background: var(--brand); color: #fff !important; border-radius: 999px; padding: 8px 18px; font-weight: 600; }
.g-top__cta:hover { background: var(--brand-deep); text-decoration: none; }

/* 阅读进度细线（Differentiator 的一部分：整页像一份被引导的手册） */
.g-progress { height: 2px; background: transparent; }
.g-progress i { display: block; height: 2px; width: 0; background: var(--brand); transition: width .12s linear; }

.g-wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.g-layout { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); gap: 48px; padding: 36px 0 72px; align-items: start; }
.g-layout > * { min-width: 0; }

/* 左侧引导轨 */
.g-rail { position: sticky; top: 76px; }
.g-rail__label { font-size: 12px; letter-spacing: .04em; color: var(--ink-3); margin: 0 0 10px; }
.g-rail ol { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line); }
.g-rail li { border-bottom: 1px solid var(--line); }
.g-rail a {
  display: grid; grid-template-columns: 26px 1fr; gap: 8px; align-items: baseline;
  padding: 11px 0; font-size: 14px; color: var(--ink-2);
}
.g-rail a b { font-weight: 600; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.g-rail a:hover { text-decoration: none; color: var(--brand); }
.g-rail a:hover b { color: var(--brand); }
.g-rail a[aria-current="true"] { color: var(--ink); }
.g-rail a[aria-current="true"] b { color: var(--brand); }
.g-rail a[aria-current="true"]::after { content: ""; display: block; }
.g-rail__foot { margin-top: 14px; font-size: 13px; color: var(--ink-3); }

/* 首屏结论卡：单一强调色做成色块（Committed），不用阴影 */
.g-hero { border-bottom: 1px solid var(--line); padding-bottom: 28px; }
.g-hero__grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 38px; align-items: start; }
.g-hero__grid > * { min-width: 0; }
/* 竖版实拍（1086×1448）：整栏铺满，高度自然超出文字栏，此时左右都从顶部开始最干净 */
.g-hero__shot--portrait { align-self: start; }
.g-hero__shot--portrait img { width: 100%; }
.g-hero__shot { margin: 0; border: 1px solid var(--line); border-radius: var(--r-shot); overflow: hidden; background: var(--bg-soft); }
.g-hero__shot img { width: 100%; height: auto; }
.g-hero__shot figcaption { font-size: 13px; color: var(--ink-3); padding: 9px 12px; border-top: 1px solid var(--line); background: #fff; }
.g-kicker { font-size: 13px; color: var(--brand); font-weight: 600; margin: 0 0 10px; }
h1 { font-size: clamp(28px, 3.4vw, 44px); line-height: 1.2; letter-spacing: -.02em; margin: 0 0 14px; text-wrap: balance; }
.g-lead { font-size: 18px; color: var(--ink-2); margin: 0 0 22px; max-width: 62ch; }

.g-answer {
  background: var(--brand);
  color: #fff;
  border-radius: var(--r-card);
  padding: 26px 28px;
  margin: 26px 0 22px;
}
.g-answer h2 { font-size: 15px; font-weight: 600; margin: 0 0 14px; color: rgba(255, 255, 255, .92); }
.g-answer dl { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 18px; margin: 0; }
.g-answer dt { font-size: 26px; line-height: 1.15; font-weight: 700; letter-spacing: -.01em; }
.g-answer dd { margin: 6px 0 0; font-size: 14px; line-height: 1.6; color: rgba(255, 255, 255, .9); }

.g-actions { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.g-btn { display: inline-block; border-radius: 999px; padding: 11px 22px; font-weight: 600; font-size: 15px; }
.g-btn--primary { background: var(--brand); color: #fff; }
.g-btn--primary:hover { background: var(--brand-deep); text-decoration: none; }
.g-btn--ghost { border: 1px solid var(--line); color: var(--ink); background: #fff; }
.g-btn--ghost:hover { border-color: var(--brand); color: var(--brand); text-decoration: none; }
.g-meta { font-size: 13px; color: var(--ink-3); margin: 14px 0 0; }

/* 分流 */
.g-fork { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; margin: 4px 0 0; }
.g-fork a { display: block; border: 1px solid var(--line); border-radius: var(--r-card); padding: 16px 18px; color: var(--ink); }
.g-fork a:hover { border-color: var(--brand); text-decoration: none; }
.g-fork strong { display: block; font-size: 16px; margin-bottom: 4px; }
.g-fork span { font-size: 14px; color: var(--ink-2); }
.g-fork em { display: block; margin-top: 10px; font-size: 14px; color: var(--brand); font-style: normal; font-weight: 600; }

.g-section { padding: 40px 0; border-top: 1px solid var(--line); }
.g-section:first-of-type { border-top: 0; }
.g-section > h2 { font-size: clamp(22px, 2.2vw, 30px); line-height: 1.25; letter-spacing: -.01em; margin: 0 0 8px; }
.g-section > h2 small { display: block; font-size: 14px; font-weight: 400; color: var(--ink-3); margin-top: 6px; letter-spacing: 0; }
.g-section > p { color: var(--ink-2); max-width: 68ch; }

/* 三步走 */
.g-steps { list-style: none; margin: 22px 0 0; padding: 0; border-top: 1px solid var(--line); }
.g-steps > li { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 20px; padding: 22px 0; border-bottom: 1px solid var(--line); }
.g-steps .no { font-size: 30px; font-weight: 700; color: var(--brand); line-height: 1; letter-spacing: -.02em; }
.g-steps h3 { font-size: 18px; margin: 0 0 6px; }
.g-steps p { margin: 0 0 12px; color: var(--ink-2); }
.g-steps .cost { font-size: 13px; color: var(--ink-3); }
.g-steps .next { font-size: 14px; }
.g-shot { border: 1px solid var(--line); border-radius: var(--r-shot); overflow: hidden; margin-top: 14px; background: var(--bg-soft); }
.g-shot figcaption { font-size: 13px; color: var(--ink-3); padding: 8px 12px; border-top: 1px solid var(--line); background: #fff; }
/* 竖版素材（手机截图、家长端页面）：限制宽度居中，避免在宽栏里被放大到一整屏 */
.g-shot--tall { display: grid; justify-items: center; background: #fff; }
.g-shot--tall img { max-width: 320px; border-bottom: 1px solid var(--line); }
.g-shot--tall figcaption { width: 100%; }
/* 竖版实拍（教室照片）需要更醒目一些：放宽到 460，并保留居中 */
.g-shot--tall-lg img { max-width: 460px; }

/* 数字基线表 */
.g-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.g-table-wrap .g-table { min-width: 640px; }
.g-table { width: 100%; border-collapse: collapse; margin-top: 20px; font-size: 15px; }
.g-table th, .g-table td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.g-table th { font-size: 13px; color: var(--ink-3); font-weight: 600; background: var(--bg-soft); }
.g-table td:first-child { font-weight: 600; }
.g-table .num { font-variant-numeric: tabular-nums; white-space: nowrap; }
.g-note { font-size: 13px; color: var(--ink-3); margin-top: 10px; }

/* 坑 */
.g-pits { list-style: none; margin: 20px 0 0; padding: 0; }
.g-pits li { display: grid; grid-template-columns: 22px minmax(0, 1fr); gap: 12px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.g-pits li b { color: var(--brand); font-weight: 700; }
.g-pits strong { display: block; }
.g-pits span { color: var(--ink-2); font-size: 15px; }
.g-settings-grid { display: grid; grid-template-columns: minmax(0, 500px) 300px; gap: 32px; align-items: end; justify-content: space-between; }
.g-settings-grid .g-pits { min-width: 0; }
.g-settings-yoyo { margin: 0; align-self: end; display: flex; justify-content: center; }
.g-settings-yoyo img { display: block; width: min(100%, 290px); height: auto; }

@media (max-width: 900px) {
  .g-settings-grid { grid-template-columns: 1fr; gap: 8px; }
  .g-settings-yoyo { justify-content: center; }
  .g-settings-yoyo img { width: min(66vw, 270px); }
}

/* FAQ */
.g-faq { margin-top: 20px; border-top: 1px solid var(--line); }
.g-faq details { border-bottom: 1px solid var(--line); }
.g-faq summary { cursor: pointer; padding: 15px 0; font-weight: 600; font-size: 16px; list-style: none; }
.g-faq summary::-webkit-details-marker { display: none; }
.g-faq summary::after { content: "+"; float: right; color: var(--brand); font-weight: 700; }
.g-faq details[open] summary::after { content: "−"; }
.g-faq p { margin: 0 0 16px; color: var(--ink-2); max-width: 68ch; }

/* 收尾 */
.g-end { border-top: 1px solid var(--line); padding: 34px 0 60px; }
.g-end h2 { font-size: 22px; margin: 0 0 8px; }
.g-links { list-style: none; margin: 20px 0 0; padding: 0; border-top: 1px solid var(--line); }
.g-links li { border-bottom: 1px solid var(--line); padding: 13px 0; font-size: 15px; }
.g-links span { color: var(--ink-3); }
.g-foot { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 22px 0; font-size: 13px; color: var(--ink-3); }

@media (max-width: 900px) {
  .g-layout { grid-template-columns: 1fr; gap: 0; padding: 22px 0 48px; }
  .g-rail { position: static; margin-bottom: 22px; }
  .g-hero__grid { grid-template-columns: 1fr; gap: 22px; }
  .g-hero__shot { margin-top: 4px; }
  .g-rail ol { display: flex; gap: 12px; overflow-x: auto; border-top: 0; padding-bottom: 4px; }
  .g-rail li { border-bottom: 0; border: 1px solid var(--line); border-radius: 999px; flex: 0 0 auto; }
  .g-rail a { grid-template-columns: auto 1fr; padding: 8px 14px; font-size: 13px; }
  .g-rail__foot { display: none; }
  .g-steps > li { grid-template-columns: 40px minmax(0, 1fr); gap: 14px; }
  .g-steps .no { font-size: 24px; }
  .g-answer { padding: 22px 20px; }
  .g-answer dt { font-size: 22px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
  .g-progress i { transition: none; }
}