:root{font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#142a35;background:#f4f8f5;font-size:17px;line-height:1.75}*{box-sizing:border-box}body{margin:0}main{width:min(100% - 32px,980px);margin:24px auto;padding:clamp(18px,4vw,40px);background:white;border:1px solid #d8e5de;border-radius:18px}header{border-bottom:1px solid #dce6e1;padding-bottom:16px}h1,h2{color:#173b38;line-height:1.25;letter-spacing:-.02em}h1{font-size:clamp(1.7rem,4vw,2.35rem)}h2{font-size:1.45rem}a{color:#096d59;text-underline-offset:3px}.back-link{font-size:.9rem;font-weight:650}button,.action{font:inherit;min-height:44px;border-radius:8px;padding:11px 17px;color:white;background:#096d59;border:1px solid #096d59;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;justify-content:center}button:hover,.action:hover{background:#075443}button:focus-visible,a:focus-visible{outline:3px solid #e99b1a;outline-offset:4px}nav{border:1px solid #d8e5de;background:#f5faf7;padding:14px 22px;border-radius:12px;margin:24px 0}nav ol{columns:2;column-gap:36px;padding-left:22px;margin:0}nav li{break-inside:avoid;margin:8px 0}section{scroll-margin-top:20px;border-bottom:1px solid #dce6e1;padding:16px 0}.flashcard{background:linear-gradient(120deg,#fffaf0,#edf7f1);border:1px solid #d5e4d9;border-radius:14px;padding:clamp(18px,4vw,32px);margin:24px 0;min-height:340px}#card-progress{font-weight:700;color:#416456;font-size:.9rem}#card-back{background:white;padding:8px 20px;border:1px solid #d9e5de;border-radius:10px;margin:20px 0}#card-reveal{margin-top:14px}.controls{display:flex;justify-content:space-between;gap:16px}.action{margin-top:24px}[hidden]{display:none!important}@media(max-width:600px){main{width:100%;margin:0;border:0;border-radius:0}nav ol{columns:1}.flashcard{min-height:0}h2{font-size:1.25rem}}