:root{--bg: #FAFAF8;--status-bg: #F2EDE3;--controls-bg: #F2EDE3;--btn-primary-bg: #2C2C2C;--btn-primary-text: #FFFFFF;--btn-secondary-bg: #E8E3D8;--btn-secondary-text: #2C2C2C;--btn-active-bg: #5A4A2E;--btn-active-text: #FFFFFF;--border: #C8BFA8;--text: #2C2C2C;--text-muted: #8A8070;--font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Noto Sans SC", "Noto Sans CJK SC", "WenQuanYi Micro Hei", system-ui, sans-serif}[hidden]{display:none!important}#welcome{flex:1;display:flex;flex-direction:column;justify-content:center;align-items:center;padding:24px;text-align:center}#welcome h1{font-size:40px;margin:0 0 12px}#welcome p{color:var(--text-muted)}.welcome-choices{display:flex;gap:16px;width:min(100%,360px);margin:20px 0}.welcome-choices button{min-height:88px;font-size:28px}#welcome-status{min-height:2.6em}button:disabled{opacity:.5;cursor:wait}#controls{box-sizing:border-box;max-width:100%}html,body{height:100%;margin:0;background:var(--bg);color:var(--text);font-family:var(--font);display:flex;flex-direction:column;align-items:stretch;-webkit-user-select:none;-moz-user-select:none;user-select:none;touch-action:none}#stats{background:var(--status-bg);border-bottom:1px solid var(--border);text-align:center;padding:8px 16px 10px;line-height:1.3;flex-shrink:0}#stats-primary{font-size:17px;font-weight:500}#stats-secondary{font-size:13px;color:var(--text-muted);margin-top:2px}.container{display:flex;justify-content:center;align-items:flex-start;flex:1 1 auto;min-height:0;padding:12px 8px 8px}#controls{background:var(--controls-bg);width:var(--board-width);border-top:1px solid var(--border);display:flex;flex-direction:column;gap:6px;padding:8px 10px 12px;flex-shrink:0;align-self:center}.btn-row{display:flex;gap:6px}button{-webkit-tap-highlight-color:transparent;font-family:var(--font);font-size:20px;border:none;border-radius:8px;cursor:pointer;min-height:48px;flex:1;padding:0 8px;transition:background .1s,color .1s,transform .08s}button.primary{background:var(--btn-primary-bg);color:var(--btn-primary-text);font-size:22px}button.secondary{background:var(--btn-secondary-bg);color:var(--btn-secondary-text);font-size:18px}button[data-ai-toggle]{position:relative;min-width:0;overflow:hidden}button[data-ai-toggle][data-loading]{font-size:12px;white-space:nowrap}button[data-ai-toggle][data-loading]:after{content:"";position:absolute;left:0;bottom:0;height:3px;width:var(--progress, 0%);background:var(--btn-active-bg)}button:active,button.primary:active{background:var(--btn-active-bg);color:var(--btn-active-text);transform:scale(.97)}#modal{display:none;position:fixed;inset:0;align-items:center;justify-content:center;background:#00000080;z-index:100;cursor:pointer}#modal-content{background:#fff;padding:24px 32px;border-radius:12px;font-size:24px;font-family:var(--font);text-align:center;white-space:pre-wrap;max-width:80vw}@media (max-width: 600px){#controls{width:100%;align-self:stretch;padding:10px 12px 18px;gap:8px}.btn-row--secondary{flex-wrap:wrap;gap:8px}.btn-row--secondary button{flex-basis:calc(50% - 4px);flex-shrink:0;min-height:54px}}