:root{--text: #6b6375;--text-h: #08060d;--bg: #fff;--border: #e5e4e7;--code-bg: #f4f3ec;--accent: #aa3bff;--accent-bg: rgba(170, 59, 255, .1);--accent-border: rgba(170, 59, 255, .5);font:18px/145% system-ui,Segoe UI,Roboto,sans-serif;color:var(--text);background:var(--bg)}#root{max-width:100%;margin:0 auto;min-height:100vh;box-sizing:border-box}body{margin:0}.home-page{padding:2rem;max-width:32rem;margin:0 auto}.home-title{margin:0 0 .5rem;font-size:clamp(1.75rem,5vw,2.5rem);font-weight:700;line-height:1.2;letter-spacing:-.03em}.home-title-line{display:block}.home-title-line:first-child{color:var(--text-h, #08060d)}.home-title-accent{background:linear-gradient(135deg,#15803d,#1d4ed8,#7c3aed);-webkit-background-clip:text;background-clip:text;color:transparent;font-weight:800;letter-spacing:.02em}.home-welcome{margin:0 0 2rem;color:var(--text, #6b6375)}.home-nav{display:flex;flex-direction:column;gap:1rem}.home-link{display:block;padding:1rem 1.5rem;border-radius:8px;font-weight:500;text-decoration:none;text-align:center;transition:background .2s,transform .1s}.home-link:active{transform:scale(.98)}.home-link-study{background:#22c55e26;color:#15803d;border:2px solid rgba(34,197,94,.4)}.home-link-study:hover{background:#22c55e40}.home-link-quiz{background:#3b82f626;color:#1d4ed8;border:2px solid rgba(59,130,246,.4)}.home-link-quiz:hover{background:#3b82f640}.home-link-stats{background:#aa3bff1a;color:#7c3aed;border:2px solid rgba(170,59,255,.4)}.home-link-stats:hover{background:#aa3bff33}.category-page{padding:2rem;max-width:28rem;margin:0 auto}.back-link{display:inline-block;margin-bottom:1rem;color:var(--accent, #aa3bff);text-decoration:none}.back-link:hover{text-decoration:underline}.category-page h1{margin:0 0 1.5rem;font-size:1.5rem;color:var(--text-h, #08060d)}.category-list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:.75rem}.category-link{display:block;padding:1rem;border-radius:8px;background:var(--code-bg, #f4f3ec);color:var(--text-h, #08060d);text-decoration:none;text-align:center;font-weight:500}.category-link:hover{background:var(--border, #e5e4e7)}.stats-page{padding:2rem;max-width:32rem;margin:0 auto}.stats-page .back-link{display:inline-block;margin-bottom:1rem;color:var(--accent, #aa3bff);text-decoration:none}.stats-page .back-link:hover{text-decoration:underline}.stats-page h1{margin:0 0 1rem;font-size:1.5rem;color:var(--text-h, #08060d)}.stats-placeholder{color:var(--text, #6b6375)}.flashcard-container{display:flex;flex-direction:column;align-items:center;gap:1.5rem}.flashcard{position:relative;width:100%;max-width:320px;min-height:180px;perspective:1000px;cursor:pointer;border:none;padding:0;background:transparent;font:inherit}.flashcard__face{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;backface-visibility:hidden;border-radius:12px;box-shadow:0 4px 12px #0000001a;background:var(--code-bg, #f4f3ec);border:2px solid var(--border, #e5e4e7);transition:transform .4s ease}.flashcard__face--front{transform:rotateY(0)}.flashcard__face--back{transform:rotateY(180deg)}.flashcard--flipped .flashcard__face--front{transform:rotateY(-180deg)}.flashcard--flipped .flashcard__face--back{transform:rotateY(0)}.flashcard__text{font-size:1.5rem;font-weight:500;color:var(--text-h, #08060d);padding:1rem;text-align:center}.flashcard-actions{display:flex;gap:1rem;flex-wrap:wrap;justify-content:center}.flashcard-actions__btn{padding:.75rem 1.25rem;border-radius:8px;font-size:1rem;font-weight:500;cursor:pointer;border:2px solid transparent;transition:background .2s,border-color .2s}.flashcard-actions__btn--right{background:#22c55e26;color:#15803d;border-color:#22c55e80}.flashcard-actions__btn--right:hover{background:#22c55e40}.flashcard-actions__btn--wrong{background:#ef44441a;color:#b91c1c;border-color:#ef444480}.flashcard-actions__btn--wrong:hover{background:#ef444433}.study-session{padding:2rem;max-width:28rem;margin:0 auto}.study-session__back{display:inline-block;margin-bottom:1rem;color:var(--accent, #aa3bff);text-decoration:none}.study-session__back:hover{text-decoration:underline}.study-session__progress{margin:0 0 1.5rem;font-size:.9rem;color:var(--text, #6b6375)}.study-session--complete{text-align:center}.study-session--complete h1{margin:0 0 .5rem;font-size:1.5rem;color:var(--text-h, #08060d)}.study-session--complete p{margin:0 0 .5rem;color:var(--text, #6b6375)}.study-session__wrong-count{font-size:.9rem;margin-top:.5rem}.study-session__home{display:inline-block;margin-top:1.5rem;padding:.75rem 1.25rem;background:var(--accent-bg, rgba(170, 59, 255, .1));color:var(--accent, #aa3bff);border-radius:8px;text-decoration:none;font-weight:500}.study-session__home:hover{background:#aa3bff33}.app{min-height:100%}