*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg: #1a1a2e;--surface: #16213e;--surface-deep: #0f3460;--surface-deep-hover: #16213e;--accent: #e94560;--accent-hover: #c73652;--accent2: #4fc3f7;--text: #eee;--text-muted: #aaa;--divider: #555;--draw-color: #ffd600;--input-border: #1a4a80}body.light-theme{--bg: #f0f4f8;--surface: #ffffff;--surface-deep: #dde3eb;--surface-deep-hover: #c8d4e0;--accent2: #0288d1;--text: #1a1a2e;--text-muted: #666;--divider: #ccc;--draw-color: #e67e00;--input-border: #b0bec5}body{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;background:var(--bg);color:var(--text);min-height:100vh;display:flex;justify-content:center;align-items:center;transition:background .3s,color .3s}.btn{padding:10px 24px;font-size:1rem;font-weight:600;background:var(--accent);color:#fff;border:none;border-radius:8px;cursor:pointer;transition:background .2s}.btn:hover:not(:disabled){background:var(--accent-hover)}.btn:disabled{opacity:.5;cursor:default}.btn.secondary{background:var(--surface-deep);color:var(--text);border:none}.btn.secondary:hover:not(:disabled){background:var(--surface-deep-hover)}.btn.small{padding:6px 16px;font-size:.85rem}