/* 白色学习空间：统一导航、科目目录、阅读、练习与模考。 */
:root{
  color-scheme:light;
  --bg:#fff;--surface:#fff;--text:#202631;--muted:#687181;--line:#e8ebf0;
  --accent:#2856cc;--accent-soft:#f0f4ff;--on-accent:#fff;--quiet:#f7f9fc;
  --unread:#4c6086;--read:#7b8491;
  font-family:"Microsoft YaHei UI","PingFang SC","Microsoft YaHei",sans-serif;line-height:1.7;
}
body{background:var(--bg)}
::selection{background:#dce7ff;color:#173675}
.workspace{grid-template-columns:216px minmax(0,1fr);align-items:start}
.sidebar{position:sticky;top:0;height:100dvh;min-height:0;padding:34px 20px 26px;gap:44px;background:#fff;color:var(--text);border-right:1px solid var(--line)}
.brand{gap:12px;padding:0 10px;font-size:18px;font-weight:650}
.brand-mark{width:34px;height:34px;border-radius:9px}
.brand small{color:var(--muted);font-size:11px;margin-top:2px;font-weight:400}
.sidebar nav{gap:7px}
.sidebar nav a{min-height:48px;padding:12px 15px;gap:13px;color:#596273;font-size:14px;font-weight:400;border-radius:8px}
.sidebar nav svg{width:19px;height:19px}
.sidebar nav a:hover{background:var(--quiet);color:var(--text)}
.sidebar nav a.active{background:var(--accent-soft);color:var(--accent);box-shadow:none;font-weight:600}
.side-bottom{border-top:1px solid var(--line);color:var(--muted);font-size:13px;padding:22px 10px 0;gap:11px}
.avatar{background:var(--quiet);color:var(--muted);width:30px;height:30px}
.topbar{height:70px;padding:0 48px;justify-content:flex-start;gap:12px;background:#fff;font-size:13px}
.workspace-label{color:var(--muted)}
.topbar-divider{color:#c7cdd7}
.content{max-width:1200px;padding:46px 48px;min-height:calc(100dvh - 70px)}
h1{font-size:32px;line-height:1.4;font-weight:650;letter-spacing:-.5px}
h2{font-weight:600}
.page-heading{margin-bottom:32px}
.eyebrow{font-size:12px;letter-spacing:0;color:var(--muted)}
.page-count{font-size:13px}
.section-heading{margin-bottom:20px}
.section-heading h2{font-size:18px;font-weight:600}
.section-heading>span{font-size:12px}
.action,.secondary{min-height:44px;padding:10px 20px;border-radius:7px;font-size:14px;gap:14px}
.action{font-weight:550}
.action:hover{background:#214bb8;filter:none}
.secondary{background:#fff;border-color:#dce1e9}
.secondary:hover{background:var(--quiet)}
.subtle-link{font-size:13px}

/* 首页：一个连续科目目录，进度来自真实阅读记录。 */
.home-heading{min-height:76px;margin-bottom:42px}
.home-heading h1{font-size:38px}
.home-heading .action{min-width:138px;min-height:46px}
.module-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:0;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.module-card{grid-template-columns:48px minmax(0,1fr) 18px;gap:20px;min-height:116px;align-items:center;padding:26px 28px;border:0;border-bottom:1px solid var(--line);border-radius:0;box-shadow:none;background:#fff}
.module-card:nth-child(odd){border-right:1px solid var(--line)}
.module-card:nth-last-child(-n+2){border-bottom:0}
.module-card:hover{background:#fafbfe}
.module-icon{display:grid;place-items:center;width:48px;height:48px;background:var(--accent-soft);border-radius:12px;color:var(--accent)}
.module-icon svg{width:25px;height:25px;color:inherit}
.module-card>svg{width:17px;height:17px;color:#8b96a8}
.module-card h3{font-size:17px;font-weight:600}
.module-meta{display:flex;flex-wrap:wrap;gap:8px 16px;margin-top:7px;font-size:12px}
.module-learned{color:var(--accent)}
.orientation-section{margin-top:42px}
.orientation-list{grid-template-columns:repeat(2,minmax(0,1fr));column-gap:36px}
.orientation-list a{min-height:56px;padding:15px 0;font-size:14px}
.orientation-list .short-state{font-size:12px;color:#7a8495}
.orientation-list svg{width:15px;height:15px}

/* 考点：当前章节的入口取代与所选科目无关的演示卡片。 */
.breadcrumb{font-size:12px;margin-bottom:24px}
.block-picker{gap:8px;margin-bottom:36px}
.block-picker a{padding:8px 14px;font-size:13px;border-color:transparent;border-radius:6px}
.block-picker a:hover{border-color:transparent}
.topics-layout{grid-template-columns:minmax(0,1fr) 230px;gap:48px}
.topic-group{margin-bottom:32px}
.topic-group h2{font-size:13px;font-weight:550;color:var(--muted);margin-bottom:6px}
.topic-row{min-height:57px;padding:15px 12px 15px 0;font-size:15px}
.topic-row.available{color:var(--text)}
.topic-row.available:hover{color:var(--accent);background:#fafbfe}
.topic-state{font-size:12px;gap:18px}
.focus-lesson{padding:24px;border-radius:10px;background:var(--quiet);border:0}
.focus-lesson .eyebrow{color:var(--muted)}
.focus-lesson h2{font-size:22px;margin:16px 0 8px}
.chapter-count{display:block;font-size:13px;color:var(--muted);margin-bottom:26px}
.supplemental{margin-top:28px}
.supplemental h3{font-size:12px}
.supplemental a{font-size:14px;padding:12px 0}

/* 阅读：白色正文、稳定翻页与清楚的当前页标记。 */
.content:has(.lesson-frame){max-width:1400px;padding-top:28px;padding-bottom:24px}
.course-page-heading{margin-bottom:22px;align-items:center}
.course-page-heading h1{font-size:25px}
.course-heading-actions{display:flex;align-items:center;gap:24px}
.course-heading-actions .action{min-height:40px;padding:8px 17px;font-size:13px}
.course-layout{grid-template-columns:minmax(0,1fr) 210px;gap:28px}
.course-layout .lesson-reader .lesson-sheet{background:#fff;padding:28px 32px;border-color:var(--line);border-radius:10px;box-shadow:none}
.lesson-reader .lesson-sheet>h2{border-bottom:1px solid var(--line);padding-bottom:18px;margin-bottom:22px;font-size:22px;font-weight:600}
.lesson-scroll{padding-top:2px;scrollbar-width:thin;scrollbar-color:#cbd2df transparent}
.lesson-reader .lesson-sheet .reading-text{max-width:760px}
.lesson-reader .lesson-sheet p{color:#303743}
.lesson-outline-panel{background:#fff;border-radius:8px;border-color:var(--line)}
.lesson-outline-panel summary{padding:16px;font-size:14px;font-weight:600}
.lesson-outline-panel nav{padding-inline:8px;scrollbar-width:thin}
.lesson-outline-panel nav a{border-left:2px solid transparent;border-radius:4px;padding:9px;font-size:13px;line-height:1.65;color:var(--unread)}
.lesson-outline-panel nav a.is-read{color:var(--read)}
.lesson-outline-panel nav a.active{border-left-color:var(--accent);color:var(--accent);background:var(--accent-soft);font-weight:550}
.lesson-outline-phase{font-size:12px;padding:16px 10px 6px;color:var(--muted)}
.lesson-controls{margin-top:8px;padding-top:18px}
.lesson-read-state{color:var(--muted)}
.lesson-track{background:#edf0f5}
.lesson-table thead th,.lesson-table tbody th{background:var(--quiet);color:var(--text)}
.worked-material,.shared-material,.map-card{background:var(--quiet)}
.worked-solution{border-top:1px solid var(--line);padding-top:25px}
.worked-solution>header{margin-bottom:18px}
.worked-solution h3{font-size:20px;color:var(--text)}
.worked-options>div{border-radius:7px;padding:13px 16px}
.worked-answer{border-radius:5px;font-weight:600}
.lesson-reader .step-list li{padding:19px 0;gap:20px}
.lesson-reader .step-list strong{font-size:18px;line-height:1.9;font-weight:400}
.practice-question,.round-feedback{box-shadow:none;border-radius:10px}
.answer-option{background:#fff}
.answer-option:hover{background:var(--quiet)}
.answer-option:has(input:checked){background:var(--accent-soft)}

/* 模考：保留配比、计时与答题状态，减少大面积色块。 */
.exam-generator{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(280px,.85fr);border:1px solid var(--line);border-radius:12px;overflow:hidden;background:#fff;margin-bottom:36px}
.exam-structure{padding:32px}
.exam-structure h2,.exam-history h2{font-size:19px;font-weight:600}
.exam-structure .section-heading{align-items:baseline;margin-bottom:28px}
.exam-structure .section-heading>span{font-size:12px}
.exam-reasoning{display:flex;flex-wrap:wrap;gap:8px 18px;border-top:1px solid var(--line);padding-top:20px;margin-top:25px;font-size:12px;color:var(--muted)}
.exam-preview{padding:32px;background:var(--quiet);border-left:1px solid var(--line);display:flex;flex-direction:column}
.exam-preview h2{font-size:23px;line-height:1.5;font-weight:600}
.exam-volume{font-size:13px;color:var(--muted);margin:6px 0 22px}
.exam-specification{display:flex;gap:32px;margin:10px 0 26px}
.exam-specification>div{display:flex;align-items:baseline;gap:9px}
.exam-specification strong{font-size:44px;line-height:1.2;font-weight:550;letter-spacing:-1px;font-variant-numeric:tabular-nums}
.exam-specification span{font-size:13px;color:var(--muted)}
.exam-distribution{display:grid;gap:14px}
.exam-distribution>div{display:grid;grid-template-columns:70px minmax(0,1fr) 42px;align-items:center;gap:12px;font-size:14px}
.exam-distribution b{font-size:13px;font-weight:400;text-align:right;font-variant-numeric:tabular-nums}
.exam-distribution-track{height:5px;background:#edf0f6;border-radius:3px;overflow:hidden}
.exam-distribution-track i{display:block;height:100%;width:0;border-radius:3px;background:#8299d4}
.exam-preview-footer{margin-top:auto;padding-top:26px;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:16px;font-size:13px}
.exam-preview-footer>span,.exam-material-groups{font-size:12px;color:var(--muted)}
.exam-material-groups{margin-top:12px}
.exam-preview-footer .action{padding-inline:24px}
#generator-error{font-size:13px;color:var(--failure);margin-top:12px}
#generator-error:empty{display:none}
.exam-generator-empty{padding:28px;border:1px solid var(--line);border-radius:10px;margin-bottom:30px}
.exam-generator-empty p{margin-top:10px;color:var(--muted)}
.paper-grid{gap:16px}
.paper-card{padding:24px;border-radius:10px;box-shadow:none}
.paper-card h3{font-size:17px;font-weight:600;line-height:1.65;overflow-wrap:anywhere}
.paper-meta{margin:13px 0;font-size:13px}
.paper-types{font-size:12px;line-height:1.8;margin-bottom:18px}
.exam-layout{grid-template-columns:minmax(0,1fr) 240px;gap:24px}
.answer-card{position:sticky;top:18px;border-radius:10px;padding:20px}
.exam-reader .lesson-sheet{border-radius:10px;padding:30px}
.exam-reader .question-stem,.exam-reader .answer-option{font-size:18px;line-height:1.9}
.exam-reader .shared-material,.exam-reader .exam-solution p{font-size:17px;line-height:1.9}
.exam-timer{color:var(--accent);font-size:28px;font-variant-numeric:tabular-nums;letter-spacing:.5px}
.exam-session-controls{display:flex;align-items:center;gap:20px;flex-shrink:0}
.content:has(.exam-layout)>.page-heading{position:sticky;top:0;background:#fff;z-index:4;padding:15px 0;margin-top:-15px}
.answer-grid{gap:7px;max-height:48vh;overflow:auto;padding:3px}
.answer-grid button{border-radius:5px;font-size:13px;min-height:34px}
.question-controls{padding-top:20px;border-top:1px solid var(--line)}

/* 账户：明确的输入边界，沿用学习区的排版和按钮。 */
.account-card,.checkout-card,.pricing-card,.admin-panel{border-radius:10px;box-shadow:none}
.account-card,.checkout-card{max-width:480px;padding:32px}
.account-card label,.admin-panel label{font-size:13px;color:#525d6e}
.account-card input,.admin-panel input,.admin-panel select,.customer-search input,textarea{background:#fff;border-color:#dce1e9}
.account-card input:focus,.admin-panel input:focus{border-color:var(--accent)}
.account-tabs button{font-size:14px}
.account-card form>.action{width:100%}
.review-row h3{font-size:15px;font-weight:500}
.review-row div>span,.review-due{font-size:12px}
.empty-state h2{font-size:18px}

@media(min-width:1600px){
  .workspace{grid-template-columns:232px minmax(0,1fr)}.sidebar{padding-inline:25px}.content{padding-top:54px}
}
@media(max-width:1200px){
  .content{padding:36px 32px}.topbar{padding-inline:32px}
  .module-card{padding:24px 22px;gap:16px}.module-card h3{font-size:16px}
  .topics-layout{gap:32px;grid-template-columns:minmax(0,1fr) 210px}
}
@media(max-width:1149px){.course-layout{grid-template-columns:1fr;gap:16px}}
@media(min-width:641px) and (max-width:1000px){
  .workspace{grid-template-columns:80px minmax(0,1fr)}
  .sidebar{padding:28px 12px;align-items:center}.brand{padding:0}
  .brand>span:last-child,.sidebar .nav-long,.sidebar .nav-short,.side-bottom #account-label{display:none}
  .sidebar nav{width:100%}.sidebar nav a{justify-content:center;padding:13px 8px}
  .sidebar nav svg{width:21px;height:21px}
  .side-bottom{width:100%;justify-content:center;padding-inline:0}
}
@media(max-width:820px){
  .topics-layout{grid-template-columns:1fr}.topic-aside{display:block}.focus-lesson{display:none}
  .module-card{padding:22px 18px;gap:13px;grid-template-columns:40px minmax(0,1fr) 15px}
  .module-icon{width:40px;height:40px;border-radius:10px}.module-icon svg{width:23px;height:23px}.module-card h3{font-size:15px}
}
@media(max-width:760px){
  .exam-layout{grid-template-columns:1fr}.answer-card{position:static}
  .exam-generator{grid-template-columns:1fr}.exam-preview{grid-row:1;border-left:0;border-bottom:1px solid var(--line)}
  .exam-preview-footer{margin-top:18px;padding-top:0}
}
@media(max-width:640px){
  .workspace{display:block}
  .sidebar{position:static;height:64px;min-height:0;flex-direction:row;align-items:center;padding:15px 20px;gap:0;border-right:0;border-bottom:1px solid var(--line)}
  .brand{padding:0;gap:9px;font-size:16px}.brand-mark{width:30px;height:30px}
  .brand small{display:inline;margin-left:10px;font-size:12px}.side-bottom{display:none}
  .sidebar nav{position:fixed;bottom:0;left:0;right:0;z-index:30;display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:0;padding:7px 8px calc(7px + env(safe-area-inset-bottom));background:#fff;border-top:1px solid var(--line)}
  .sidebar nav a{display:flex;flex-direction:column;justify-content:center;gap:3px;min-height:49px;padding:4px;border-radius:6px;font-size:11px;line-height:1.5}
  .sidebar nav svg{width:21px;height:21px}
  .sidebar nav .nav-long{display:none}.sidebar nav .nav-short{display:inline}
  .sidebar nav a.active{background:transparent}.topbar{display:none}
  .content{padding:30px 20px calc(94px + env(safe-area-inset-bottom));min-height:calc(100dvh - 64px)}
  h1{font-size:27px}.page-heading{margin-bottom:28px;gap:16px;align-items:center}
  .page-heading .action{font-size:13px;padding:10px 15px;gap:10px}
  .home-heading{min-height:60px;margin-bottom:32px}.home-heading h1{font-size:30px}
  .home-heading .action{min-width:118px;min-height:42px}
  .section-heading{margin-bottom:16px}.section-heading h2{font-size:17px}
  .module-grid{grid-template-columns:1fr;border-radius:10px}
  .module-card{grid-template-columns:42px minmax(0,1fr) 17px;gap:17px;padding:19px 20px;min-height:88px}
  .module-card:nth-child(odd){border-right:0}.module-card:nth-last-child(2){border-bottom:1px solid var(--line)}
  .module-icon{width:42px;height:42px}.module-card h3{font-size:16px}.module-meta{margin-top:4px}
  .orientation-section{margin-top:32px}.orientation-list{grid-template-columns:1fr}
  .orientation-list a{font-size:14px;min-height:55px}
  .block-picker{flex-wrap:nowrap;overflow-x:auto;margin-inline:-20px;padding:0 20px 8px;gap:5px;scrollbar-width:none;margin-bottom:24px}
  .block-picker a{white-space:nowrap;flex-shrink:0;padding:7px 11px}.topic-row{font-size:15px}
  .content:has(.lesson-frame){padding:22px 16px calc(86px + env(safe-area-inset-bottom))}
  .course-page-heading{gap:12px;margin-bottom:16px}.course-page-heading h1{font-size:20px;line-height:1.5}
  .course-heading-actions{gap:10px}.course-heading-actions .page-count{display:none}
  .course-heading-actions .action{font-size:12px;padding:8px 12px;min-height:36px}
  .lesson-outline-panel summary{padding:10px 14px;font-size:13px}
  .course-layout .lesson-reader .lesson-sheet{padding:19px 20px;border-radius:8px}
  .lesson-reader .lesson-sheet>h2{font-size:20px;margin-bottom:16px;padding-bottom:13px}
  .lesson-scroll{padding-right:4px}.lesson-controls{gap:12px;padding-top:12px}
  .lesson-controls .action,.lesson-controls .secondary{min-height:42px;padding:10px 16px;font-size:14px}
  .lesson-reader .step-list strong{font-size:17px}.lesson-reader .step-list li{gap:13px}
  .exam-structure,.exam-preview{padding:25px 22px}.exam-structure .section-heading{display:block}
  .exam-structure .section-heading>span{display:block;margin-top:6px}
  .exam-reader .lesson-sheet{padding:22px 19px}.exam-reader .question-stem,.exam-reader .answer-option{font-size:17px}
  .content:has(.exam-layout)>.page-heading{flex-wrap:wrap;gap:12px}
  .content:has(.exam-layout)>.page-heading h1{font-size:21px}
  .exam-session-controls{width:100%;justify-content:space-between}.exam-timer{font-size:25px}.answer-grid{max-height:220px}
  .account-card,.checkout-card,.pricing-card,.admin-panel{padding:24px 20px}
  .account-card input,.admin-panel input,.admin-panel select{font-size:16px}
}
@media(max-width:359px){
  .content{padding-inline:16px}.home-heading h1{font-size:26px}
  .home-heading .action{min-width:108px;padding-inline:12px}.module-card{padding-inline:16px}
}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;scroll-behavior:auto!important}}