:root{color-scheme:light dark;--paper:light-dark(#f6f5ef,#1e2521);--surface:light-dark(#fff,#28312b);--ink:light-dark(#233b2c,#eef4ef);--quiet:light-dark(#58675c,#b8c8bd);--line:light-dark(#d8e0d5,#47594b);--accent:light-dark(#275d43,#add6b8);--on-accent:light-dark(#fff,#173723);--error:light-dark(#943628,#ffb4a6)}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.6 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}a{color:inherit;text-underline-offset:4px}button,input,select,textarea{font:inherit}button,.button{display:inline-block;min-height:44px;padding:10px 16px;border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:8px;text-decoration:none;cursor:pointer;text-align:center}button:hover,.button:hover{filter:brightness(.96)}button:disabled{opacity:.6;cursor:wait}button.primary,.button.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}:focus-visible{outline:3px solid var(--accent);outline-offset:4px}button.text-button{border:0;background:none;padding:8px;color:var(--quiet)}.site-header{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap;padding:22px max(24px,calc((100% - 1120px)/2));border-bottom:1px solid var(--line)}.brand{font-size:14px;letter-spacing:.07em;font-weight:650;text-decoration:none}.brand span{font-weight:400;letter-spacing:0;color:var(--quiet)}nav,.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}nav{font-size:14px;gap:22px}nav a{text-decoration:none}main{max-width:820px;margin:auto;padding:36px 24px 24px}.page-intro{margin:12px 0 28px}h1,h2,p{overflow-wrap:anywhere}h1{font-size:clamp(1.7rem,4vw,2.1rem);line-height:1.25;font-weight:550;letter-spacing:-.03em;margin:12px 0 18px}h2{font-size:1.05rem;font-weight:600;margin:20px 0 8px}p{margin:12px 0}.eyebrow{font-size:13px;letter-spacing:.055em;text-transform:uppercase;color:var(--quiet);margin-top:0}.muted{color:var(--quiet)}.helper{font-size:14px;margin:8px 0}.panel{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:28px}.row select{flex:1;min-width:180px}.between{justify-content:space-between}label{display:block;font-weight:550;margin:16px 0 8px}label:first-child{margin-top:0}input,select,textarea{background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:11px 12px;max-width:100%}input,textarea{display:block;width:100%}textarea{resize:vertical;min-height:140px}pre{margin:0;white-space:pre-wrap;overflow-wrap:anywhere;tab-size:4;font-size:15px;line-height:1.65}.problem{background:var(--paper);border-radius:8px;padding:24px;margin:22px 0 12px}.math-problem pre{font-family:Georgia,"Times New Roman",serif;font-size:1.35rem}.exercise-top{margin-bottom:24px;font-size:14px}.actions{margin-top:20px}.hint,.feedback{border-left:3px solid var(--accent);padding:2px 20px;margin-top:26px}.feedback p{white-space:pre-wrap}.answer-copy{white-space:pre-wrap;overflow-wrap:anywhere;background:var(--paper);padding:16px;border-radius:8px}.site-footer{max-width:772px;margin:20px auto;padding:22px 24px;border-top:1px solid var(--line);font-size:14px;color:var(--quiet)}.subjects{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-top:40px}.subjects p:last-child{font-size:14px}.history-row{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:20px 0;border-bottom:1px solid var(--line);text-decoration:none}.history-row:hover{text-decoration:underline}.status{color:var(--quiet);font-size:14px;flex-shrink:0}.resume-list{margin-top:30px}.login-panel{max-width:450px;margin:36px auto}.login-panel button{width:100%;margin-top:24px}.notice{padding:14px 18px;border:1px solid var(--line);background:var(--surface);border-radius:8px}.notice.error{color:var(--error)}.next-form{margin:24px 0}.save-status{min-height:23px}
.self-assessment-actions{margin-top:20px}
@media(max-width:560px){.site-header{padding:18px;gap:10px}nav{gap:14px;flex-wrap:wrap}main{padding:22px 16px}.panel{padding:20px}.row select{width:100%;flex-basis:100%}.subjects{grid-template-columns:1fr;gap:8px;margin-top:26px}.subjects p{margin:6px 0}.history-row{align-items:flex-start;flex-direction:column;gap:4px}.problem{padding:18px}.site-footer{margin:20px 16px;padding:18px 0}.actions{gap:8px}.actions button,.self-assessment-actions button{flex-grow:1}}