:root{--bg: #0a0a0a;--bg-surface: #141414;--bg-hover: #1a1a1a;--text: #e0e0e0;--text-dim: #888;--text-bright: #fff;--accent: #4ade80;--error: #f87171;--warning: #fbbf24;--border: #2a2a2a;--font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", "Consolas", monospace;--max-width: 640px}*{margin:0;padding:0;box-sizing:border-box}html,body{height:100%;background:var(--bg);color:var(--text);font-family:var(--font-mono);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}button{font-family:var(--font-mono);cursor:pointer;border:1px solid var(--border);background:var(--bg-surface);color:var(--text);padding:.5rem 1rem;font-size:.875rem;transition:background .15s,border-color .15s,transform .1s}button:hover{background:var(--bg-hover);border-color:var(--text-dim);transform:translateY(-1px)}button:active{transform:translateY(0);background:var(--bg)}button:disabled{opacity:.4;cursor:not-allowed;transform:none}button.primary{background:var(--accent);color:var(--bg);border-color:var(--accent);font-weight:600}button.primary:hover{filter:brightness(1.1)}button.primary:active{filter:brightness(.95)}button.primary:disabled{filter:none}input[type=text]{font-family:var(--font-mono);font-size:1.125rem;background:var(--bg-surface);border:1px solid var(--border);color:var(--text-bright);padding:.75rem 1rem;width:100%;outline:none;transition:border-color .15s}input[type=text]:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 15%,transparent)}input[type=text]::placeholder{color:var(--text-dim)}select{font-family:var(--font-mono);font-size:.875rem;background:var(--bg-surface);border:1px solid var(--border);color:var(--text);padding:.5rem 1rem;outline:none;appearance:none;cursor:pointer}select:focus{border-color:var(--accent)}.container{max-width:var(--max-width);margin:0 auto;padding:2rem 1rem}.flash-correct{animation:flash-green .4s ease-out}.flash-wrong{animation:flash-red .4s ease-out}@keyframes flash-green{0%{background-color:#4ade8033}to{background-color:transparent}}@keyframes flash-red{0%{background-color:#f8717133}to{background-color:transparent}}@keyframes fade-in{0%{opacity:0}to{opacity:1}}@keyframes slide-up{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}@keyframes shake{0%,to{transform:translate(0)}20%,60%{transform:translate(-3px)}40%,80%{transform:translate(3px)}}@keyframes pulse-glow{0%,to{box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 30%,transparent)}50%{box-shadow:0 0 0 5px color-mix(in srgb,var(--accent) 15%,transparent)}}