:root{--bg: #10131a;--surface: #1a1f2b;--surface-2: #232a3a;--text: #e8ecf4;--muted: #8b93a7;--accent: #4f8cff;--good: #3ddc84;--bad: #ff5c5c;--warn: #ffb347;--radius: 12px}*{box-sizing:border-box;margin:0}html,body,#root{height:100%}body{background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,sans-serif;-webkit-font-smoothing:antialiased}button{font:inherit;color:inherit;background:var(--surface);border:1px solid var(--surface-2);border-radius:var(--radius);min-height:44px;padding:0 16px;cursor:pointer;transition:background .15s,border-color .15s,transform .05s}button:active{transform:scale(.97)}button:disabled{opacity:.5;cursor:default}.screen{max-width:480px;min-height:100dvh;margin:0 auto;display:flex;flex-direction:column;gap:20px;padding:16px;padding-top:calc(16px + env(safe-area-inset-top));padding-bottom:calc(16px + env(safe-area-inset-bottom))}.play-screen{justify-content:flex-start}.muted{color:var(--muted);font-size:14px}.home-screen{justify-content:center}.home-header{text-align:center;margin-bottom:8px}.home-header h1{font-size:44px;letter-spacing:-1px;background:linear-gradient(120deg,var(--accent),var(--good));-webkit-background-clip:text;background-clip:text;color:transparent}.tagline{color:var(--muted);margin-top:6px}.picker h2{font-size:13px;text-transform:uppercase;letter-spacing:1px;color:var(--muted);margin-bottom:8px}.segmented{display:flex;flex-wrap:wrap;gap:8px}.segmented button{flex:1 1 auto;border-radius:999px}.segmented button.selected{background:var(--accent);border-color:var(--accent);color:#fff;font-weight:600}.home-footer{display:flex;flex-direction:column;gap:10px;text-align:center;margin-top:8px}.high-score{color:var(--warn);font-weight:600}.play-btn{background:var(--accent);border-color:var(--accent);color:#fff;font-size:20px;font-weight:700;min-height:56px;border-radius:var(--radius)}.daily-btn{display:flex;flex-direction:column;gap:2px;align-items:flex-start;padding:12px 16px;background:linear-gradient(120deg,#1c2740,#1a1f2b);border:1px solid var(--accent);min-height:60px}.daily-title{font-size:17px;font-weight:700;color:var(--text)}.daily-sub{font-size:13px;color:var(--warn)}.share-btn{color:var(--accent);border-color:var(--surface-2)}.share-msg{text-align:center}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:20;background:#06080cb8;display:flex;align-items:center;justify-content:center;padding:20px}.modal-card{background:var(--surface);border:1px solid var(--surface-2);border-radius:16px;padding:22px 20px;max-width:400px;width:100%;display:flex;flex-direction:column;gap:16px}.modal-card h2{font-size:22px;text-align:center}.rules{list-style:none;padding:0;display:flex;flex-direction:column;gap:14px}.rules li{display:flex;gap:12px;font-size:15px;line-height:1.4}.rule-icon{font-size:20px;flex-shrink:0}.secondary-actions{display:flex;gap:8px}.secondary-actions button{flex:1;font-weight:600}.review-btn:not(:disabled){border-color:var(--good);color:var(--good)}.stats-btn{color:var(--muted)}.toggles{display:flex;justify-content:center;gap:8px;margin-top:4px}.toggle{font-size:13px;min-height:38px;padding:0 12px;color:var(--muted);opacity:.6}.toggle.on{opacity:1;color:var(--text)}.stats-header{text-align:center}.stats-header h1{font-size:26px}.stats-empty{text-align:center;margin-top:20px;line-height:1.5}.stat-tiles{display:flex;gap:10px}.tile{flex:1;background:var(--surface);border-radius:var(--radius);padding:16px 8px;display:flex;flex-direction:column;align-items:center;gap:4px}.tile-value{font-size:26px;font-weight:800;font-variant-numeric:tabular-nums}.tile-value em{font-style:normal;font-size:15px;color:var(--muted)}.tile-label{font-size:12px;text-transform:uppercase;letter-spacing:.5px;color:var(--muted)}.mastery-legend{display:flex;justify-content:center;gap:16px;font-size:13px}.legend strong{font-size:16px}.legend.mastered{color:var(--good)}.legend.learning{color:var(--warn)}.legend.struggling{color:var(--bad)}.cat-progress h2{font-size:14px;text-transform:uppercase;letter-spacing:1px;color:var(--muted);margin-bottom:12px}.cat-row{margin-bottom:14px}.cat-row-head{display:flex;justify-content:space-between;font-size:14px;margin-bottom:6px}.cat-bar{height:10px;background:var(--surface);border-radius:999px;overflow:hidden}.cat-bar-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--good));border-radius:999px;transition:width .4s ease}.stats-footer{margin-top:auto}.stats-footer .home-btn{width:100%}.play-screen{gap:16px;position:relative}.correct-flash{position:fixed;top:0;right:0;bottom:0;left:0;pointer-events:none;z-index:5;background:radial-gradient(circle at center,rgba(61,220,132,.28),transparent 70%);animation:flash-out .45s ease-out forwards}@keyframes flash-out{0%{opacity:1}to{opacity:0}}.play-header{display:flex;align-items:center;gap:12px}.score{font-size:24px;font-weight:700;font-variant-numeric:tabular-nums;min-width:48px}.streak-badge{background:var(--surface);border-radius:999px;padding:4px 10px;font-size:14px;white-space:nowrap}.streak-badge.hot{background:#3a2a12;color:var(--warn)}.streak-badge em{font-style:normal;font-weight:700}.timer-bar{position:relative;flex:1;height:28px;background:var(--surface);border-radius:999px;overflow:hidden}.timer-fill{height:100%;background:var(--accent);border-radius:999px;transition:width .1s linear}.timer-fill.warn{background:var(--bad)}.timer-text{position:absolute;top:0;right:0;bottom:0;left:0;display:grid;place-items:center;font-size:14px;font-weight:700;font-variant-numeric:tabular-nums;text-shadow:0 1px 2px rgba(0,0,0,.6)}.question{display:flex;flex-direction:column;gap:12px;animation:slide-in .2s ease-out}@keyframes slide-in{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}.chip{align-self:flex-start;font-size:12px;font-weight:700;text-transform:uppercase;letter-spacing:1px;padding:4px 10px;border-radius:999px;background:var(--surface-2);color:var(--muted)}.chip-definitions{color:var(--accent)}.chip-system-design{color:var(--good)}.chip-bug-hunt{color:var(--warn)}.chip-patterns{color:#c58cff}.chip-web{color:#4fd6d6}.chip-diagrams{color:#ff9db1}.question-image{display:flex;justify-content:center;padding:8px;background:#0b0e14;border:1px solid var(--surface-2);border-radius:var(--radius)}.question-image svg{width:100%;max-width:320px;height:auto}.prompt{font-size:19px;line-height:1.45}.code-block{background:#0b0e14;border:1px solid var(--surface-2);border-radius:var(--radius);padding:12px;overflow-x:auto;font-family:ui-monospace,Cascadia Code,Consolas,monospace;font-size:14px;line-height:1.5}.answer-area{display:flex;flex-direction:column;gap:12px}.answer-zone{position:relative;cursor:text}.answer-zone .ghost-input{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%;padding:0;border:0;background:transparent;color:transparent;caret-color:transparent;font-size:16px;outline:none;text-align:center}.type-hint{text-align:center;margin-top:-4px}.boxes{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}.word{display:flex;flex-wrap:wrap;justify-content:center;gap:4px;max-width:100%}.box{width:clamp(22px,7.2vw,30px);height:40px;display:grid;place-items:center;background:var(--surface);border:1px solid var(--surface-2);border-radius:8px;font-size:20px;font-weight:700;text-transform:uppercase;font-family:ui-monospace,Consolas,monospace}.box.hint{color:var(--muted)}.box.revealed{background:#3a2a12;border-color:var(--warn);color:var(--warn)}.box.current{border-color:var(--accent);box-shadow:0 0 0 2px #4f8cff59;animation:caret-blink 1.1s ease-in-out infinite}@keyframes caret-blink{50%{box-shadow:0 0 0 2px #4f8cff1a}}.actions{display:flex;gap:10px}.actions button{flex:1;min-height:48px;color:var(--muted)}.hint-btn:not(:disabled){color:var(--warn)}.hint-text{background:#2a2412;border:1px solid #4a3d1c;border-radius:var(--radius);padding:10px 14px;color:var(--warn);font-size:15px;line-height:1.4;animation:slide-in .2s ease-out}.results-header{text-align:center;display:flex;flex-direction:column;gap:8px}.results-header h1{font-size:28px}.new-high{color:var(--warn);font-weight:700}.final-score{font-size:64px;font-weight:800;font-variant-numeric:tabular-nums;background:linear-gradient(120deg,var(--accent),var(--good));-webkit-background-clip:text;background-clip:text;color:transparent}.stats{display:flex;justify-content:center;gap:20px;color:var(--muted);font-size:14px}.stats strong{color:var(--text);font-size:16px}.review h2{font-size:16px;margin-bottom:10px}.missed-list{list-style:none;padding:0;display:flex;flex-direction:column;gap:10px}.missed-card{background:var(--surface);border-radius:var(--radius);padding:12px 14px;display:flex;flex-direction:column;gap:8px}.missed-prompt{color:var(--muted);font-size:14px;line-height:1.4}.missed-answer{color:var(--good);font-weight:700}.results-footer{display:flex;flex-direction:column;gap:10px;margin-top:auto}