.chapter-courses{--chapter-color:#fff;padding:88px 0 96px}
.chapter-courses .courses{display:grid;grid-template-columns:minmax(0,.82fr) minmax(0,1.18fr);gap:56px;padding:0;scroll-margin-top:125px;align-items:stretch}
.courses-copy{padding:16px 0;min-width:0}
.chapter-courses .courses h2{font-size:42px;line-height:1.1;letter-spacing:-.035em;text-wrap:balance}
.courses-heading h2 span{color:#0953d8}
.courses-heading p{font-size:17px;line-height:1.55;margin-top:18px;color:#465976;max-width:430px}
.courses button,.sample-lesson{font:inherit;-webkit-tap-highlight-color:transparent}
.school-switch{display:flex;width:max-content;max-width:100%;margin-top:28px;border:1px solid #c8d8ec;border-radius:10px;overflow:hidden}
.school-switch button{border:0;background:#fff;color:#10265a;padding:7px 16px;min-height:48px;min-width:112px;font-weight:600;font-size:14px;line-height:1.3;cursor:pointer}
.school-switch button span{display:block;font-size:11px;font-weight:400;line-height:1.4;margin-top:2px}
.school-switch button[aria-pressed=true]{background:#0953d8;color:#fff}
.subject-switch{display:flex;justify-content:space-between;gap:10px;margin-top:22px;border-bottom:1px solid #dfe7ef}
.subject-switch button{position:relative;border:0;background:transparent;color:#465976;padding:10px 0 12px;min-height:44px;font-size:15px;font-weight:500;cursor:pointer}
.subject-switch button[aria-pressed=true]{color:#0953d8;font-weight:700}
.subject-switch button[aria-pressed=true]::after{content:"";position:absolute;inset:auto 0 -1px;height:3px;background:#0953d8;border-radius:3px}
.courses button:focus-visible,.sample-lesson:focus-visible{outline:3px solid #10265a;outline-offset:4px}
.school-switch button:focus-visible{outline-offset:-5px}
.course-content{margin-top:24px}
.course-description h3{font-size:25px;line-height:1.2;letter-spacing:-.025em;text-wrap:initial}
.course-coverage{font-size:16px;line-height:1.4;color:#465976;margin-top:6px}
.course-description h4{font-size:15px;font-weight:600;margin-top:22px;margin-bottom:6px}
.course-description ul{padding:0;margin:0;list-style:none}
.course-description li{padding:2px 0;font-size:16px;color:#465976;line-height:1.5}
.sample-lesson{display:inline-flex;align-items:center;justify-content:center;min-height:54px;padding:14px 25px;margin-top:24px;background:#ff6a24;color:#fff;text-decoration:none;border-radius:12px;font-size:16px;font-weight:700;line-height:1.4}
.sample-lesson:hover{background:#e95714}
.courses .course-note{margin-top:18px;font-size:12px;line-height:1.5;color:#465976}
.course-status{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
.faculty-carousel{--teacher-blue:#0953d8;--panel-duration:490ms;--panel-ease:cubic-bezier(.232,.604,.265,.989);min-width:0;min-height:0;height:560px;align-self:center;position:relative;isolation:isolate}
.course-teachers{display:flex;gap:12px;height:100%;width:100%;min-height:inherit;align-items:stretch}
.courses .course-teacher{position:relative;flex:1 1 0;min-width:0;border:0;padding:0;overflow:hidden;border-radius:16px;background:var(--teacher-blue);color:#fff;cursor:pointer;text-align:left;isolation:isolate;transition:flex-grow var(--panel-duration) var(--panel-ease),transform var(--panel-duration) var(--panel-ease);transform:translateY(0);contain:layout paint;user-select:none}
.courses .course-teacher.is-active{flex-grow:3;transform:translateY(-3px)}
.course-teacher::after{content:"";position:absolute;inset:48% 0 0;background:linear-gradient(180deg,transparent,rgba(4,28,77,.12) 35%,rgba(4,28,77,.86));pointer-events:none}
.courses .course-teacher>img{position:absolute;left:50%;top:0;transform:translateX(calc(-1 * var(--portrait-center,50%)));height:var(--portrait-height,150%);width:auto;max-width:none;object-fit:contain;pointer-events:none}
.teacher-details{position:absolute;z-index:1;left:22px;right:18px;bottom:26px;opacity:0;transform:translateY(12px);transition:opacity 180ms ease,transform 300ms ease;pointer-events:none}
.teacher-details strong{display:block;color:#fff;font-size:27px;line-height:1.1;font-weight:600;letter-spacing:-.02em}
.teacher-details>span{display:block;color:#fff;font-size:14px;line-height:1.45;margin-top:9px;max-width:260px}
.is-active .teacher-details{opacity:1;transform:translateY(0);transition-delay:160ms}
.teacher-spine{position:absolute;z-index:2;left:50%;bottom:25px;transform:translateX(-50%) rotate(180deg);writing-mode:vertical-rl;white-space:nowrap;color:#fff;font-size:18px;font-weight:600;line-height:1.2;opacity:1;transition:opacity 180ms ease;pointer-events:none}
.is-active .teacher-spine{opacity:0}
.courses .course-teacher:focus-visible{outline:3px solid #fff;outline-offset:-6px}
@media(max-width:1150px){.chapter-courses .courses{gap:32px;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr)}.chapter-courses .courses h2{font-size:36px}.teacher-details{left:16px;right:12px}.teacher-details strong{font-size:23px}.teacher-details>span{font-size:13px}.subject-switch button{font-size:14px}.course-teachers{gap:10px}}
@media(max-width:800px){.chapter-courses{padding:56px 0 64px}.chapter-courses .courses{grid-template-columns:1fr;gap:32px}.courses-copy{padding:0}.chapter-courses .courses h2{font-size:36px;max-width:560px}.courses-heading p{max-width:530px}.school-switch{margin-top:24px}.subject-switch{max-width:520px}.faculty-carousel{height:480px}.courses .course-note{max-width:530px}.teacher-details strong{font-size:25px}}
@media(max-width:480px){.chapter-courses .courses h2{font-size:32px}.courses-heading p{font-size:16px}.subject-switch button{font-size:14px}.faculty-carousel{height:400px}.course-teachers{gap:8px}.courses .course-teacher{border-radius:12px}.courses .course-teacher.is-active{flex-grow:3.4}.teacher-details{left:13px;right:10px;bottom:20px}.teacher-details strong{font-size:21px}.teacher-details>span{font-size:12px}.teacher-spine{font-size:15px;bottom:20px}.sample-lesson{width:100%}}
@media(prefers-reduced-motion:reduce){.courses .course-teacher,.teacher-details,.teacher-spine{transition:none!important;transform:none}.courses .course-teacher.is-active{transform:none}.teacher-spine{transform:translateX(-50%) rotate(180deg)}}

/* Hold a complete, centred reading view once the preceding blue surface has left. */
.chapter-courses.is-course-scene{
  padding-top:var(--course-stage-top);padding-bottom:var(--course-stage-bottom);
  min-height:calc(100svh + var(--course-stage-hold));
}
.chapter-courses.is-course-scene .courses{position:sticky;top:var(--course-stage-top)}
.chapter-courses.is-course-scene #courses{scroll-margin-top:var(--course-stage-top)}

/* Editorial course explorer: introduction, navigation, then one shared stage. */
.chapter-courses .courses{display:block}
.chapter-courses .courses-heading{display:grid;grid-template-columns:minmax(0,1fr) 290px;align-items:end;gap:48px;margin-bottom:36px}
.chapter-courses .courses .courses-heading h2{font-size:48px;line-height:1.12;letter-spacing:-.035em;text-wrap:initial;margin:0}
.chapter-courses .courses .courses-heading h2 span{color:#0953d8}
.chapter-courses .courses-heading p{margin:0 0 4px;font-size:17px;line-height:1.6;max-width:290px}
.course-navigation{display:flex;align-items:center;gap:56px;padding:0 0 20px;border-bottom:1px solid #cfdbed}
.courses .school-switch{flex:none;margin:0;background:#eef3fc;border-color:transparent;padding:3px;border-radius:12px;overflow:visible}
.courses .school-switch button{background:transparent;border-radius:8px;min-width:112px;min-height:48px;transition:background-color 180ms,color 180ms}
.courses .school-switch button[aria-pressed=true]{background:#0953d8;color:#fff}
.courses .subject-switch{position:relative;flex:1;max-width:none;align-self:stretch;align-items:center;justify-content:space-between;gap:24px;margin:0;border:0}
.courses .subject-switch button{min-height:54px;padding:12px 0;font-size:18px;color:#465976;font-weight:500;white-space:nowrap}
.courses .subject-switch button[aria-pressed=true]{color:#0953d8;font-weight:600}
.courses .subject-switch button[aria-pressed=true]::after{display:none}
.subject-indicator{position:absolute;bottom:-21px;left:0;height:3px;width:var(--subject-width,130px);background:#0953d8;transform:translateX(var(--subject-left,0px));transition:width 240ms ease,transform 240ms ease;pointer-events:none}
.chapter-courses .course-content{display:grid;grid-template-columns:minmax(0,.85fr) minmax(0,1.9fr);gap:56px;align-items:start;margin-top:32px;min-width:0}
.chapter-courses .course-description{padding:20px 0 0;min-width:0}
.chapter-courses .course-description h3{font-size:32px;line-height:1.16;letter-spacing:-.03em;max-width:330px;margin:0}
.chapter-courses .course-coverage{margin-top:12px;font-size:15px}
.chapter-courses .course-description h4{margin:28px 0 12px;font-size:13px;color:#10265a;font-weight:600}
.chapter-courses .course-description li{font-size:16px;line-height:1.5;padding:7px 0;border-bottom:1px solid #e4eaf3}
.chapter-courses .course-description li:last-child{border-bottom:0}
.chapter-courses .sample-lesson{margin-top:28px;padding:15px 28px;min-height:54px;font-size:16px;background:var(--orange);color:#fff}
.chapter-courses .sample-lesson:hover{background:var(--orange-hover)}
.chapter-courses .faculty-carousel{height:420px;align-self:start;--teacher-blue:#0953d8}
.courses .course-teacher{border-radius:14px}
.courses .course-teachers[data-count="1"]{max-width:520px;margin-left:auto}
.courses .course-teachers[data-count="1"] .course-teacher{cursor:default}
.courses .course-teachers[data-count="1"] .course-teacher.is-active{transform:none}
.courses .teacher-details strong{font-size:28px}
.courses .teacher-details>span{font-size:14px;max-width:330px}
.courses ::selection{background:#dbe8ff;color:#10265a}
@media(min-width:1400px){.chapter-courses .faculty-carousel{height:440px}.chapter-courses .courses .courses-heading h2{font-size:52px}}
@media(max-width:1100px){
 .chapter-courses .courses-heading{grid-template-columns:minmax(0,1fr) 240px;gap:32px}
 .chapter-courses .courses .courses-heading h2{font-size:40px}
 .course-navigation{gap:32px}
 .courses .subject-switch{gap:16px}.courses .subject-switch button{font-size:16px}
 .chapter-courses .course-content{gap:32px;grid-template-columns:minmax(0,.9fr) minmax(0,1.7fr)}
 .chapter-courses .course-description h3{font-size:28px}
 .chapter-courses .faculty-carousel{height:400px}
}
@media(max-width:800px){
 .chapter-courses .courses-heading{display:block;margin-bottom:28px}
 .chapter-courses .courses .courses-heading h2{font-size:38px;max-width:none}
 .chapter-courses .courses-heading p{max-width:480px;margin:16px 0 0;font-size:16px}
 .course-navigation{display:block;padding-bottom:0}
 .courses .subject-switch{margin-top:16px;gap:16px}
 .subject-indicator{bottom:-1px}
 .chapter-courses .course-content{gap:24px;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);margin-top:24px}
 .chapter-courses .course-description{padding:8px 0 0}
 .chapter-courses .course-description h3{font-size:26px}
 .chapter-courses .faculty-carousel{height:400px}
 .courses .teacher-details strong{font-size:22px}.courses .teacher-details>span{font-size:12px}
}
@media(max-width:600px){
 .chapter-courses .courses .courses-heading h2{font-size:32px;line-height:1.15;letter-spacing:-.035em}
 .courses .subject-switch{gap:12px}.courses .subject-switch button{font-size:14px;font-weight:500}
 .chapter-courses .course-content{grid-template-columns:1fr;gap:24px}
 .chapter-courses .course-description h3{max-width:none;font-size:27px}
 .chapter-courses .course-description h4{margin-top:20px;margin-bottom:8px}
 .chapter-courses .course-description li{padding:4px 0;border:0;font-size:15px}
 .chapter-courses .sample-lesson{width:auto;margin-top:20px}
 .chapter-courses .faculty-carousel{height:360px}
 .courses .teacher-details strong{font-size:22px}
 .courses .course-teachers[data-count="1"]{max-width:none}
}
@media(prefers-reduced-motion:reduce){.subject-indicator,.courses .school-switch button{transition:none}}

/* Resolve Chinese teacher names directly instead of scanning system fallback fonts. */
#courses .teacher-details strong,#courses .teacher-spine,#courses .mobile-teacher strong{font-family:Inter,Arial,'Microsoft YaHei','PingFang SC',sans-serif}