:root {
  --paper: #f8f5ed;
  --ink: #5b5953;
  --accent: #d66b4a;
  --rule: color-mix(in srgb, var(--ink) 18%, var(--paper));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: "Noto Sans SC", sans-serif; -webkit-font-smoothing: antialiased; }
.app-shell { min-height: 100vh; display: block; }
.section-kicker, .eyebrow { text-transform: uppercase; letter-spacing: .13em; font-size: 10px; color: var(--ink); }
.main-content { max-width: 1180px; width: 100%; margin: 0 auto; padding: 0 5vw; }
.intro-section { padding: 90px 0 112px; max-width: 780px; }
.eyebrow { color: var(--accent); margin-bottom: 23px; }
.intro-section h1 { color: var(--accent); font-family: "Noto Serif SC", serif; font-size: clamp(46px, 6vw, 80px); line-height: 1.12; letter-spacing: -.07em; margin: 0; font-weight: 800; }
.intro-section h1 em { font-style: normal; color: var(--accent); }
.intro-copy { max-width: 520px; color: var(--ink); font-size: 16px; line-height: 1.8; margin: 26px 0 34px; }
.intro-actions { display: flex; align-items: center; gap: 24px; }
.primary-btn { border: 1px solid var(--accent); background: var(--accent); color: var(--paper); padding: 13px 17px 13px 20px; border-radius: 0; font: 600 13px "Noto Sans SC", sans-serif; cursor: pointer; }
.primary-btn span { margin-left: 13px; color: var(--paper); font-size: 16px; }
.text-btn { border: 0; background: transparent; color: var(--accent); padding: 10px 0; font: 600 13px "Noto Sans SC", sans-serif; cursor: pointer; }
.text-btn span { margin-left: 8px; color: var(--accent); }
.current-section { padding: 0 0 106px; }
.section-heading { display: flex; justify-content: space-between; align-items: end; border-top: 1px solid var(--accent); padding-top: 24px; margin-bottom: 28px; }
.section-kicker { margin-bottom: 10px; color: var(--accent); }
.section-heading h2 { color: var(--accent); font-family: "Noto Serif SC", serif; font-size: 24px; letter-spacing: -.03em; margin: 0; font-weight: 700; }
.module-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.module-card { border: 1px solid var(--accent); background: var(--paper); border-radius: 0; padding: 20px 20px 18px; min-height: 146px; cursor: pointer; transition: background .2s, transform .2s; }
.module-card:hover, .module-card.open { background: var(--accent); color: var(--paper); transform: translateY(-2px); }
.module-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.module-number { color: var(--accent); font-size: 11px; }
.module-card:hover .module-number, .module-card.open .module-number, .module-card:hover .module-arrow, .module-card.open .module-arrow { color: var(--paper); }
.module-arrow { color: var(--accent); font-size: 15px; transition: transform .2s; }
.module-card.open .module-arrow { transform: rotate(45deg); }
.module-card h3 { color: var(--accent); font-family: "Noto Serif SC", serif; font-size: 17px; letter-spacing: -.02em; margin: 0 0 8px; font-weight: 700; }
.module-card:hover h3, .module-card.open h3, .module-card:hover .module-problem, .module-card.open .module-problem { color: var(--paper); }
.module-problem { color: var(--ink); font-size: 12px; line-height: 1.6; margin: 0; max-width: 390px; }
.lesson-list { display: none; border-top: 1px solid var(--paper); margin-top: 17px; padding-top: 12px; }
.module-card.open .lesson-list { display: block; }
.lesson-row { display: flex; gap: 12px; padding: 8px 0; border-bottom: 1px solid var(--paper); align-items: baseline; }
.lesson-row:last-child { border-bottom: 0; }
.lesson-id { color: var(--paper); font-size: 10px; min-width: 25px; }
.lesson-name { color: var(--paper); font-size: 12px; line-height: 1.45; }
.task-label { margin-left: auto; color: var(--paper); font-size: 10px; white-space: nowrap; }
.method-section { padding: 0 0 100px; }
.loop-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--accent); border: 1px solid var(--accent); margin-top: 28px; }
.loop-step { background: var(--paper); padding: 22px 20px; min-height: 145px; }
.loop-step span { color: var(--accent); font-size: 11px; }
.loop-step strong { display: block; color: var(--accent); font-family: "Noto Serif SC", serif; font-size: 16px; margin: 24px 0 9px; }
.loop-step p { margin: 0; color: var(--ink); font-size: 12px; line-height: 1.6; }
.method-quote { margin-top: 32px; background: var(--accent); padding: 27px 30px 24px; max-width: 760px; }
.quote-mark { color: var(--paper); font-family: Georgia, serif; font-size: 40px; line-height: .5; }
.method-quote p { color: var(--paper); font-family: "Noto Serif SC", serif; font-size: 18px; line-height: 1.65; letter-spacing: -.02em; margin: 10px 0 17px; max-width: 620px; }
.quote-by { color: var(--paper); font-size: 10px; }
.site-footer { border-top: 1px solid var(--accent); padding: 24px 0 35px; display: flex; justify-content: space-between; color: var(--ink); font-size: 11px; }
.site-footer span { color: var(--accent); padding: 0 4px; }
.footer-right { font-size: 10px; }
@media (max-width: 850px) {
  .main-content { padding: 0 22px; }
  .intro-section { padding: 68px 0 75px; }
  .intro-section h1 { font-size: clamp(42px, 12vw, 65px); }
  .intro-copy { font-size: 15px; }
  .section-heading { display: block; }
  .module-grid { grid-template-columns: 1fr; }
  .loop-grid { grid-template-columns: repeat(2, 1fr); }
  .site-footer { display: block; }
  .footer-right { margin-top: 10px; }
}
@media (max-width: 440px) {
  .intro-actions { display: block; }
  .text-btn { margin-top: 13px; }
  .loop-grid { grid-template-columns: 1fr; }
  .method-quote { padding: 22px; }
  .method-quote p { font-size: 16px; }
  .lesson-row { align-items: flex-start; }
  .task-label { display: none; }
}

/* ===== 课程文案页 ===== */
.lesson-row.has-script { cursor: pointer; }
.lesson-row.has-script .lesson-name { text-decoration: underline; text-underline-offset: 3px; }
.script-link { margin-left: auto; color: var(--paper); font-size: 11px; white-space: nowrap; }
.lesson-view { max-width: 760px; padding: 48px 0 96px; }
.back-link { display: inline-block; color: var(--ink); font-size: 14px; text-decoration: none; padding: 6px 0; }
.back-link:hover { color: var(--accent); }
.lesson-kicker { margin: 36px 0 12px; font-size: 13px; letter-spacing: .04em; color: var(--ink); }
.lesson-title { font-family: "Noto Serif SC", serif; font-weight: 800; font-size: clamp(30px, 5vw, 44px); line-height: 1.25; margin: 0 0 14px; color: var(--accent); }
.lesson-question { font-size: 17px; line-height: 1.8; margin: 0 0 32px; color: var(--ink); }
.takeaway { background: var(--accent); color: var(--paper); padding: 22px 26px; margin-bottom: 40px; }
.takeaway span { font-size: 13px; }
.takeaway p { margin: 8px 0 0; font-family: "Noto Serif SC", serif; font-size: 20px; line-height: 1.6; font-weight: 700; }
.plan-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px 40px; margin-bottom: 56px; }
.plan-grid h3, .wrap-up h3 { font-family: "Noto Serif SC", serif; font-size: 17px; margin: 0 0 10px; color: var(--ink); }
.plan-grid ul, .wrap-up ul { margin: 0; padding-left: 1.2em; }
.plan-grid li, .wrap-up li { font-size: 15px; line-height: 1.8; margin-bottom: 6px; }
.plan-grid p, .wrap-up p { font-size: 15px; line-height: 1.8; margin: 0; }
.segment { margin-bottom: 52px; }
.seg-head { display: flex; align-items: baseline; gap: 12px; border-bottom: 1px solid var(--ink); padding-bottom: 10px; margin-bottom: 18px; }
.seg-no { font-family: "Noto Serif SC", serif; font-weight: 800; font-size: 22px; color: var(--accent); }
.seg-head h3 { font-family: "Noto Serif SC", serif; font-size: 22px; margin: 0; color: var(--ink); }
.seg-time { margin-left: auto; font-size: 14px; color: var(--ink); }
.sc-line { display: grid; grid-template-columns: 4.6em 1fr; gap: 12px; margin: 0 0 14px; }
.sc-line p { margin: 0; font-size: 17px; line-height: 1.9; max-width: 65ch; }
.sc-who { font-weight: 700; font-size: 15px; line-height: 2.2; color: var(--ink); }
.sc-who::before { content: ""; display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 6px; background: var(--ink); }
.sc-who.kid::before { background: var(--accent); }
.sc-who.both::before { background: transparent; border: 2px solid var(--accent); width: 8px; height: 8px; box-sizing: border-box; }
.sc-dir { display: grid; grid-template-columns: 4.6em 1fr; gap: 12px; margin: 18px 0; padding: 12px 14px; background: color-mix(in srgb, var(--accent) 9%, var(--paper)); }
.sc-dir p { margin: 0; font-size: 14px; line-height: 1.8; }
.sc-tag { font-size: 13px; font-weight: 700; color: var(--ink); }
.wrap-up { display: grid; gap: 32px; border-top: 1px solid var(--ink); padding-top: 32px; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
@media (max-width: 850px) { .plan-grid { grid-template-columns: 1fr; } }
@media (max-width: 440px) { .sc-line, .sc-dir { grid-template-columns: 1fr; gap: 2px; } .sc-who { line-height: 1.6; } }

/* ===== 顶栏、年份选择、更新进度 ===== */
.site-header { border-bottom: 1px solid var(--rule); }
.header-inner { max-width: 1180px; margin: 0 auto; padding: 0 5vw; height: 64px; display: flex; align-items: center; justify-content: space-between; }
.brand-lockup { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand-mark { color: var(--accent); font-size: 26px; line-height: 1; }
.brand-name { color: var(--accent); font-weight: 700; font-size: 16px; letter-spacing: .02em; }
.brand-url { font-size: 12px; color: var(--ink); }
.year-nav { display: grid; grid-template-columns: repeat(5, 1fr); border-bottom: 1px solid var(--rule); margin-bottom: 40px; }
.year-link { border: 0; border-bottom: 3px solid transparent; margin-bottom: -1px; background: transparent; padding: 14px 0 13px; color: var(--ink); font: 500 15px "Noto Sans SC", sans-serif; text-align: center; cursor: pointer; transition: border-color .2s; }
.year-link:hover { border-bottom-color: color-mix(in srgb, var(--accent) 45%, transparent); }
.year-link.active { font-weight: 700; border-bottom-color: var(--accent); }
.current-section .section-heading { border-top: 0; padding-top: 0; }
.year-note { margin: 10px 0 0; max-width: 60ch; color: var(--ink); font-size: 14px; line-height: 1.7; }
.year-progress { display: flex; align-items: center; gap: 12px; padding-bottom: 4px; color: var(--ink); font-size: 13px; white-space: nowrap; }
.year-progress b { font-size: 16px; }
.progress-bar { width: 72px; height: 4px; border-radius: 2px; background: var(--rule); overflow: hidden; }
.progress-bar i { display: block; height: 100%; background: var(--accent); }
@media (max-width: 850px) {
  .header-inner { padding: 0 22px; height: 56px; }
  .year-progress { margin-top: 14px; }
}