:root{color-scheme:light;font-family:ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;color:#243450;background:#f4f7ff}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:radial-gradient(ellipse 700px 400px at 10% 0%,#e9e8ff 0,transparent 85%),radial-gradient(ellipse 650px 420px at 95% 10%,#e6f6fa 0,transparent 80%),#f6f8fd}main{max-width:1020px;margin:0 auto;padding:24px 20px 76px}header{display:flex;justify-content:space-between;align-items:center;gap:15px;padding:7px 0 18px;border-bottom:1px solid #e4e9f2}h1{font-size:1.4rem;letter-spacing:-.04em;margin:0}.brand{text-decoration:none;color:#253a69;display:inline-flex;gap:10px;align-items:center}.brand-icon{display:grid;place-items:center;color:white;background:linear-gradient(135deg,#8f75ec,#547cd7);border-radius:13px;width:42px;height:42px;font-size:1.5rem;box-shadow:0 6px 15px #5b63d433}.header-label{color:#7684a0;font-size:.84rem}section{background:#fff;border:1px solid #e7eaf4;border-radius:23px;padding:30px;margin:23px 0;box-shadow:0 8px 30px #233e6c0a}h2{margin:0 0 12px;font-size:1.55rem;color:#25365a;letter-spacing:-.03em}p{line-height:1.6}a{color:#4262b3}button{font:inherit;border:0;background:linear-gradient(135deg,#6379df,#4b68ce);color:#fff;border-radius:12px;padding:12px 18px;cursor:pointer;font-weight:700;box-shadow:0 3px 8px #586bd82b}button:hover{filter:brightness(1.06)}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #a8b6ff;outline-offset:3px}.subtle{background:#edf1fa;color:#41547d;box-shadow:none}form{display:grid;gap:14px}label{display:grid;gap:7px;font-weight:650}input{font:inherit;padding:13px;border:1px solid #ccd5e7;border-radius:12px;max-width:100%;min-width:0;background:white}nav{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-top:17px;color:#53627b}nav form{display:block}.ok,.error{padding:13px;border-radius:12px}.ok{background:#e0f7ea}.error{background:#ffe6e6}.eyebrow{display:block;font-size:.72rem;letter-spacing:.15em;font-weight:800;color:#7665c2;margin-bottom:13px}.welcome-panel{padding:40px 36px 43px;background:linear-gradient(150deg,#fff,#fbfcff)}.welcome-panel>p{color:#6d7893;margin:0 0 30px}.subjects{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.subject-tile{display:flex;flex-direction:column;gap:14px;padding:25px 21px;min-height:185px;border:1px solid #dcdff7;border-radius:20px;background:linear-gradient(150deg,#eff0ff,#faf8ff);text-decoration:none;color:#273960;font-size:1.13rem;font-weight:750;transition:transform .2s,box-shadow .2s,border-color .2s}.subject-tile:hover{transform:translateY(-3px);box-shadow:0 12px 22px #52679518;border-color:#aeb9ee}.subject-emoji{display:inline-grid;place-items:center;background:#fff;width:58px;height:58px;border-radius:16px;font-size:1.8rem;box-shadow:0 4px 15px #34458b10}.subject-foot{display:flex;align-items:center;justify-content:space-between;margin-top:auto;color:#62729a;font-size:.79rem;font-weight:600}.subject-biology{background:linear-gradient(145deg,#e9f8f0,#f9fffb);border-color:#ccebdd}.subject-geography{background:linear-gradient(145deg,#fff2e4,#fffbf6);border-color:#f5dfc8}.login-panel{max-width:520px;margin:45px auto;padding:38px}.login-panel p{color:#7b87a0}.login-panel button{margin-top:5px}.item{border-top:1px solid #e5eaf0;display:flex;justify-content:space-between;align-items:center;padding:12px 0;gap:14px}.item small,summary small{display:block;color:#7886a0;font-size:.77rem;margin-top:6px}details{background:#f5f7ff;border:1px solid #e1e6f3;border-radius:15px;padding:17px;min-height:75px}summary{cursor:pointer;font-weight:750;color:#3b5798}details p{font-size:1.25rem}.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(205px,1fr));gap:12px}.question{text-align:center;font-size:clamp(1.35rem,5vw,2rem);padding:28px;background:#f2f5fd;border-radius:15px;margin-bottom:18px}.hint{font-size:.84rem;color:#7886a0}@media(max-width:720px){main{padding:16px 13px 40px}header{align-items:flex-start}h1{font-size:1.15rem}.brand-icon{width:36px;height:36px}.header-label{display:none}section{padding:23px 19px;border-radius:19px}.welcome-panel{padding:30px 21px}.subjects{grid-template-columns:1fr;gap:12px}.subject-tile{min-height:105px;display:grid;grid-template-columns:56px 1fr;align-items:center;gap:5px 13px}.subject-emoji{grid-row:span 2}.subject-foot{margin-top:0}nav{gap:8px;flex-wrap:wrap}}@media(prefers-reduced-motion:reduce){.subject-tile{transition:none}.subject-tile:hover{transform:none}}