:root{--bg-base: #0a0a0a;--bg-surface: #121212;--bg-elevated: #1e1e1e;--bg-hover: #252525;--bg-active: #2a2a2a;--border: #262626;--border-light: #333;--text-primary: #e0e0e0;--text-secondary: #a0a0a0;--text-muted: #737373;--text-faint: #4a4a4a;--accent: #4CAF50;--accent-hover: #43a047;--accent-glow: rgba(76, 175, 80, .25);--error: #f44336;--warning: #f89f1b;--info: #2196F3;--easy: #4CAF50;--medium: #f57c00;--hard: #f44336;font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:dark;color:var(--text-primary);background-color:var(--bg-base);font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{font-weight:500;color:var(--accent);text-decoration:inherit}a:hover{color:var(--accent-hover)}body{margin:0;min-width:320px;min-height:100vh}*{scrollbar-width:thin;scrollbar-color:var(--text-faint) var(--bg-surface)}*::-webkit-scrollbar{width:8px;height:8px}*::-webkit-scrollbar-track{background:var(--bg-surface)}*::-webkit-scrollbar-thumb{background:var(--text-faint);border-radius:4px}*::-webkit-scrollbar-thumb:hover{background:var(--text-muted)}h1{font-size:3.2em;line-height:1.1}button{border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;background-color:var(--bg-elevated);cursor:pointer;transition:border-color .25s}button:hover{border-color:var(--accent)}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}