/* Reading layout: chapter list, question sheet, and plain explanation notes. */
:root{background:#fff;color:#252a28;--line:#e3e6e4;--muted:#747b77;--green:#246651}
.topbar{max-width:1160px;padding:22px 32px;gap:24px}
.brand{font-family:inherit;font-size:21px;letter-spacing:0}
.nav{color:#5f6662}.nav.active{background:#f1f3f1;color:#252a28}
.account{background:#f3f4f3;border-radius:4px}
main{max-width:1060px;margin:32px auto 64px}
h1{font-size:27px;letter-spacing:0}h2{font-size:21px}h3{font-size:16px}
button,.button,input,select{border-radius:4px!important}
.panel{border:0;border-radius:0;padding:24px 0;margin-bottom:24px;box-shadow:none}
.heading{margin-bottom:12px}
.home-stats,.resume-row,.practice-setup{max-width:940px;margin-left:auto;margin-right:auto}
.home-stats{margin-bottom:22px}.small-stats{display:flex;gap:10px;font-size:12px}.small-stats b{font-size:16px}.small-stats span:first-of-type{margin-right:16px}
.resume-row{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:16px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin-bottom:22px}
.resume-row>div{display:flex;align-items:center;gap:18px;font-size:14px}.resume-row span{color:var(--muted);font-size:13px}
.practice-setup .panel{padding-top:0}
.segmented{padding:0;background:none;border-radius:0;border-bottom:1px solid var(--line);gap:24px;margin:12px 0 28px}
.segmented button{flex:0 1 auto;border-radius:0!important;padding:12px 2px;color:#646b67}
.segmented .selected{background:none;box-shadow:none;border-bottom:2px solid var(--green);color:var(--green);font-weight:600}
.chapter-range{max-width:640px}.range-shortcuts{gap:20px;margin:4px 0 14px}
.scope-description{background:none;border-radius:0;padding:12px 0;margin:0;color:#545d57;font-size:13px}
.chapters{gap:0 24px}.chapter{border:0;border-bottom:1px solid var(--line);border-radius:0;padding:13px 8px;font-size:14px;line-height:1.6;min-height:51px}
.chapter strong{font-size:12px;display:inline-block;min-width:22px;color:#707a73}.chapter small{font-size:12px}.chapter input{margin-right:8px}.chapter.checked{background:#f1f6f2;border-color:var(--line)}
.start-row{margin-top:26px;padding-top:22px}.start-row .fine{margin-bottom:0}
.question-card{border:0;border-radius:0;padding:20px 8px;box-shadow:none;background:#fff}
.question-meta .pill{background:none;padding:0;color:#6b746e}
.chapter-label{color:#68726b}.question-card h1{color:#252a28;font-size:24px}
.option,.option.chosen,.option.correct{border:0;border-bottom:1px solid var(--line);border-left:3px solid transparent;border-radius:0;padding:18px 14px;background:#fff}
.options{gap:0;border-top:1px solid var(--line)}
.option.chosen{border-left-color:var(--green);background:#f5f8f5}.option.correct{border-left-color:#378768;background:#f5f8f5}
.option.reference{border-left:3px dashed #a98236;background:#fcfaf3}
.option-label{border:0;border-radius:0;background:none;font-size:16px;color:#4d5851}.chosen .option-label{background:none;color:var(--green);font-weight:700}
.answer{margin-top:36px;padding:28px 0 0;border:0;border-top:2px solid #353e38;border-radius:0;background:none}
.answer-reference{padding:10px 0 16px;border:0;border-radius:0;background:none}
.analysis-section{margin-top:24px;padding-top:20px;border-top:1px solid var(--line)}
.analysis-section h3{font-size:16px;margin-bottom:12px}.answer .concept{font-size:16px;color:#303b34}
.prose strong{color:inherit}.prose blockquote{border-left-color:#bec6c0;background:#f8f9f8}
.rationales{display:block;margin:0;padding:0;list-style:none}
.rationales>li{border:0;border-bottom:1px solid var(--line);border-radius:0;padding:14px 0;background:none;gap:16px}
.rationales>li:last-child{border-bottom:0}.rationale-label{background:none;border-radius:0;font-size:15px;flex-basis:22px;color:#424e46}
.pitfalls{background:none;border:0;border-top:1px solid var(--line);border-radius:0;padding:20px 0 0}
.pitfalls h3{color:#303b34}.pitfalls li::marker{color:#66736a}
.assumptions{border-radius:0;background:#f7f8f7;color:#555f58}
.katex-display{background:none;border-radius:0;padding:10px 2px}
.warning{border-radius:4px}.review-notes{background:#faf9f5;border:0;border-left:2px solid #d1c29d}
.source{margin-top:28px}.feedback{border-radius:4px;background:#f3f6f2}
.login{max-width:520px;margin-top:10vh}.login .panel{margin-top:28px}.login .brand{font-size:23px}
footer{max-width:1060px;border-top:1px solid var(--line);padding-top:16px}
@media(max-width:900px){.home-stats{display:none}.topbar{padding:18px 24px;gap:12px}}
@media(max-width:600px){
 .topbar{padding:16px 18px;gap:14px}.topbar .brand{font-size:19px}
 main{margin-top:24px;padding:0 18px}.panel{padding:16px 0}.practice-setup .panel{padding-top:0}
 h1{font-size:24px}h2{font-size:21px}.heading{margin-bottom:16px}
 .resume-row{padding:14px 0;margin-bottom:24px;gap:12px}.resume-row>div{display:block}.resume-row span{display:block;margin-top:5px}
 .segmented{gap:25px}.segmented button{font-size:14px}
 .chapters{gap:0 12px}.chapter{font-size:12px;min-height:64px;padding:11px 4px}.chapter small{display:none}.chapter strong{font-size:11px;min-width:18px}.chapter input{margin-right:5px}
 .question-card{padding:12px 0}.question-card h1{font-size:22px}
 .option,.option.chosen,.option.correct{padding:16px 8px;gap:10px}
 .answer{margin:30px 0 0;padding:24px 0 0}.answer-reference{padding:8px 0 12px}
 .rationales>li{padding:14px 0;gap:12px}.pitfalls{padding:20px 0 0}
 footer{padding:16px 18px}.login{margin-top:36px}.login .brand{font-size:22px}
}