:root{--color-bg: #f5f5f5;--color-black: #1a1a1a;--color-white-piece: #f0f0f0;--color-white-text: #888;--color-cell: #2d8a4e;--color-cell-hover: #34a05a;--color-line: #1e6e3e;--color-board-border: #1a1a1a;--color-last-move: rgba(255, 50, 50, .7);--board-size: min(88vw, 88vh, 480px);font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}*{margin:0;padding:0;box-sizing:border-box}body{background:var(--color-bg);color:var(--color-black);min-height:100svh;-webkit-tap-highlight-color:transparent;-webkit-user-select:none;user-select:none}.header{display:flex;flex-direction:column;align-items:center;gap:4px;padding:20px 0 8px}.header-logo{width:48px;height:48px}.header-icon{width:100%;height:100%;object-fit:contain}.header-title{font-size:1.4rem;font-weight:800;color:var(--color-black);letter-spacing:1px;text-transform:uppercase;margin:0}.header-subtitle{font-size:.75rem;color:#999;letter-spacing:2px;text-transform:uppercase;margin:0}.user-bar{display:flex;align-items:center;justify-content:flex-end;gap:12px;padding:8px 16px;width:100%;max-width:520px}.user-info{display:flex;align-items:center;gap:8px}.user-name{font-size:.9rem;font-weight:600;color:#1a1a1a}.user-rating{font-size:.8rem;color:#666;background:#e8e8e8;padding:2px 8px;border-radius:10px;font-weight:600}.user-logout{background:none;border:1px solid #ccc;border-radius:4px;padding:3px 10px;font-size:.8rem;color:#666;cursor:pointer;transition:all .15s}.user-logout:hover{border-color:#1a1a1a;color:#1a1a1a}.user-logout:disabled{border-color:#e2e2e2;color:#a9a9a9;cursor:default}.user-logout:disabled:hover{border-color:#e2e2e2;color:#a9a9a9}.auth-container{display:flex;justify-content:center;align-items:center;min-height:80svh;padding:20px}.auth-card{width:100%;max-width:340px;display:flex;flex-direction:column;align-items:center;gap:12px}.auth-logo{width:64px;height:64px}.auth-logo img{width:100%;height:100%;object-fit:contain}.auth-title{font-size:1.4rem;font-weight:800;letter-spacing:1px;text-transform:uppercase;margin:0 0 4px}.auth-card h2{font-size:1rem;font-weight:600;color:#666;margin:0}.auth-form{display:flex;flex-direction:column;gap:10px;width:100%;margin-top:8px}.auth-input{width:100%;padding:10px 12px;border:1.5px solid #ccc;border-radius:6px;font-size:.95rem;background:#fff;color:#1a1a1a;outline:none;transition:border-color .15s}.auth-input:focus{border-color:#1a1a1a}.auth-btn{width:100%;padding:10px;background:#1a1a1a;color:#fff;border:none;border-radius:6px;font-size:.95rem;font-weight:600;cursor:pointer;transition:opacity .15s}.auth-btn:hover{opacity:.85}.auth-btn:disabled{opacity:.5;cursor:not-allowed}.auth-switch{background:none;border:none;color:#666;font-size:.85rem;cursor:pointer;padding:4px}.auth-switch:hover{color:#1a1a1a}.auth-error{color:#d32f2f;font-size:.85rem;margin:0;text-align:center}.auth-helper{margin:-2px 2px 2px;color:#777;font-size:.76rem;line-height:1.45}.auth-success{color:#2e7d32;font-size:.9rem;text-align:center}.mode-select{display:flex;flex-direction:column;align-items:center;gap:24px;padding:40px 20px}.mode-loading{font-size:.85rem;color:#999}.mode-title{font-size:1.1rem;font-weight:700;color:#1a1a1a;letter-spacing:1px}.mode-buttons{display:flex;gap:16px;flex-wrap:wrap;justify-content:center}.mode-btn{display:flex;flex-direction:column;align-items:center;gap:10px;padding:20px 28px;border:2px solid #ddd;border-radius:12px;background:#fff;cursor:pointer;transition:all .15s}.mode-btn:hover{border-color:#1a1a1a;transform:translateY(-2px)}.mode-icon{width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center}.mode-icon--black{background:#1a1a1a}.mode-icon--white{background:#f0f0f0;border:2px solid #ccc}.mode-icon--random{background:linear-gradient(135deg,#1a1a1a 50%,#f0f0f0 50%);border:2px solid #ccc;font-size:1.2rem;font-weight:800;color:#888}.mode-label{font-size:.9rem;font-weight:600;color:#333}.mode-btn:disabled{opacity:.4;cursor:default;transform:none}@media(max-width:520px){.mode-select{width:100%;padding:28px 0 20px;gap:18px}.mode-buttons{width:100%;gap:8px;flex-wrap:nowrap}.mode-btn{flex:1 1 0;min-width:0;padding:16px 10px;gap:8px}.mode-icon{width:34px;height:34px}.mode-label{font-size:.82rem}}@media(max-width:380px){.mode-buttons{gap:6px}.mode-btn{padding:14px 6px}.mode-icon{width:30px;height:30px}.mode-label{font-size:.76rem}}.cell{aspect-ratio:1;background:var(--color-cell);border:1px solid var(--color-line);display:flex;align-items:center;justify-content:center;cursor:default;position:relative}.cell--valid{cursor:pointer}.cell--valid:hover{background:var(--color-cell-hover)}.cell--last:after{content:"";position:absolute;width:8px;height:8px;border-radius:50%;background:var(--color-last-move)}.piece{width:80%;height:80%;border-radius:50%;transition:transform .15s ease}.piece--black{background:radial-gradient(circle at 35% 35%,#555,#111);box-shadow:1px 2px 4px #0006}.piece--white{background:radial-gradient(circle at 35% 35%,#fff,#ccc);box-shadow:1px 2px 4px #00000040}.hint{width:28%;height:28%;border-radius:50%;background:#ffffff4d}.score{font-size:clamp(10px,2.5vw,14px);font-weight:700;font-variant-numeric:tabular-nums;line-height:1;text-shadow:0 1px 2px rgba(0,0,0,.5)}.score--positive{color:#4ade80}.score--negative{color:#f87171}.score--zero{color:#fbbf24}.cell--wrong{background:#d32f2f66!important}.practice-comments-overlay{position:fixed;inset:0;background:#0000006b;display:flex;align-items:center;justify-content:center;padding:16px;z-index:1200;box-sizing:border-box}.practice-comments-card{width:min(100%,560px);max-height:min(88svh,760px);background:#fff;border-radius:8px;box-shadow:0 18px 48px #0000002e;display:flex;flex-direction:column;overflow:hidden}.practice-comments-header{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;padding:18px 20px 14px;border-bottom:1px solid #ececec}.practice-comments-header h2{margin:0;font-size:1.05rem;color:#1a1a1a}.practice-comments-notice{margin:6px 0 0;font-size:.82rem;color:#777}.practice-comments-close{border:none;background:none;color:#666;cursor:pointer;font-size:1.5rem;line-height:1}.practice-comments-body{min-height:220px;padding:14px 20px;flex:1;display:flex}.practice-comments-empty{width:100%;display:flex;align-items:center;justify-content:center;color:#888;font-size:.9rem}.practice-comments-list{width:100%;overflow-y:auto;display:flex;flex-direction:column;gap:10px;padding-right:4px}.practice-comment-item{border:1px solid #e8e8e8;border-radius:8px;padding:10px 12px;background:#fff}.practice-comment-item--own{border-color:#d4d4d4;background:#fafafa}.practice-comment-meta{display:flex;align-items:center;gap:8px;margin-bottom:6px}.practice-comment-author{font-size:.86rem;font-weight:700;color:#1f1f1f}.practice-comment-time{font-size:.74rem;color:#8a8a8a;margin-left:auto}.practice-comment-delete{border:none;background:none;color:#999;font-size:.76rem;cursor:pointer;padding:0}.practice-comment-delete:hover:not(:disabled){color:#c62828}.practice-comment-delete:disabled{cursor:default;opacity:.45}.practice-comment-content{white-space:pre-wrap;word-break:break-word;font-size:.9rem;line-height:1.5;color:#333}.practice-comments-composer{border-top:1px solid #ececec;padding:14px 20px 18px}.practice-comments-input{width:100%;min-height:92px;resize:vertical;border:1px solid #d8d8d8;border-radius:8px;padding:10px 12px;box-sizing:border-box;font:inherit;color:#222}.practice-comments-input:focus{outline:none;border-color:#1a1a1a}.practice-comments-actions{margin-top:10px;display:flex;align-items:center;justify-content:space-between;gap:12px}.practice-comments-length{font-size:.78rem;color:#8a8a8a}.practice-comments-submit{border:1px solid #1a1a1a;border-radius:8px;background:#1a1a1a;color:#fff;padding:8px 18px;font-size:.86rem;font-weight:600;cursor:pointer}.practice-comments-submit:disabled{opacity:.45;cursor:default}@media(max-width:520px){.practice-comments-overlay{padding:10px}.practice-comments-card{max-height:min(92svh,760px)}.practice-comments-header,.practice-comments-body,.practice-comments-composer{padding-left:14px;padding-right:14px}}.board-container{display:flex;flex-direction:column;align-items:center;gap:16px}.board-status{display:flex;align-items:center;justify-content:space-between;width:100%;max-width:var(--board-size);padding:8px 4px}.status-pieces{display:flex;align-items:center;gap:6px;font-size:1.3rem;font-weight:700;font-variant-numeric:tabular-nums}.piece-count--black{color:var(--color-black)}.piece-count--white{color:var(--color-white-text)}.status-separator{color:#999}.status-turn{font-size:.9rem;color:#666}.status-current{display:flex;align-items:center;gap:6px}.turn-indicator{display:inline-block;width:12px;height:12px;border-radius:50%;border:1px solid #999}.turn--black{background:var(--color-black)}.turn--white{background:var(--color-white-piece);border-color:#ccc}.status-gameover{font-weight:700;color:var(--color-black)}.board-wrapper{display:flex;flex-direction:column}.col-labels{display:flex}.corner-spacer{width:20px;flex-shrink:0}.col-label{flex:1;text-align:center;font-size:.75rem;color:#888;padding-bottom:2px;text-transform:uppercase}.board-with-rows{display:flex}.row-labels{display:flex;flex-direction:column;width:20px;flex-shrink:0}.row-label{flex:1;display:flex;align-items:center;justify-content:center;font-size:.75rem;color:#888}.board-grid{display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr);width:var(--board-size);height:var(--board-size);border:2px solid var(--color-board-border);border-radius:2px}.board-footer{display:flex;align-items:center;justify-content:space-between;width:100%;max-width:var(--board-size);padding:0 4px}.board-actions{display:flex;gap:8px}.solver-info{font-size:.75rem;color:#999;font-variant-numeric:tabular-nums}.btn-reset{background:none;border:1.5px solid var(--color-black);color:var(--color-black);padding:6px 20px;font-size:.85rem;font-weight:600;cursor:pointer;border-radius:2px;letter-spacing:.5px;text-transform:uppercase;transition:background .15s,color .15s}.btn-reset:hover{background:var(--color-black);color:#fff}.challenge-container{display:flex;flex-direction:column;align-items:center;gap:8px;width:100%;max-width:520px;position:relative}.challenge-toolbar,.review-toolbar{width:100%;display:flex;align-items:center}.challenge-toolbar{justify-content:flex-start}.review-toolbar{justify-content:space-between;gap:10px}.btn-challenge-back,.btn-review-back{padding:8px 14px;background:none;color:#666;border:1px solid #ccc;border-radius:6px;font-size:.85rem;cursor:pointer}.btn-challenge-back:hover,.btn-review-back:hover{border-color:#1a1a1a;color:#1a1a1a}.challenge-timer{width:100%;display:flex;align-items:center;gap:8px}.timer-bar{flex:1;height:6px;background:#e0e0e0;border-radius:3px;overflow:hidden}.timer-fill{height:100%;background:#1a1a1a;transition:width 1s linear;border-radius:3px}.timer-fill.timer-danger{background:#d32f2f}.timer-text{font-size:.85rem;font-weight:700;color:#1a1a1a;min-width:36px;text-align:right}.timer-danger-text{color:#d32f2f}.challenge-info{display:flex;gap:12px;align-items:center;font-size:.8rem;color:#666}.info-empties,.info-rating{background:#f0f0f0;padding:2px 8px;border-radius:8px;font-weight:600}.side-indicator{display:flex;align-items:center;gap:6px;padding:3px 12px;border-radius:14px;font-weight:700;font-size:.85rem}.status-ai{font-size:.85rem;color:#999}.status-deep-think{font-size:.85rem;color:#e65100;font-weight:600}.review-actions{display:flex;gap:8px;flex-wrap:nowrap;justify-content:center;width:100%}.challenge-result{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:#00000080;border-radius:8px;z-index:10}.challenge-confirm-overlay{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:#0000006b;border-radius:8px;z-index:12}.challenge-confirm-card{width:min(100%,320px);background:#fff;border-radius:14px;padding:20px 20px 18px;display:flex;flex-direction:column;gap:12px;box-shadow:0 18px 42px #0000002e}.challenge-confirm-title{color:#1a1a1a;font-size:1rem;font-weight:700;text-align:center}.challenge-confirm-text{color:#666;font-size:.86rem;line-height:1.6;text-align:center}.challenge-confirm-actions{display:flex;gap:10px}.challenge-confirm-cancel,.challenge-confirm-quit{flex:1;padding:9px 12px;border-radius:8px;font-size:.9rem;cursor:pointer;transition:all .15s ease}.challenge-confirm-cancel{background:none;color:#666;border:1px solid #ccc}.challenge-confirm-cancel:hover{border-color:#1a1a1a;color:#1a1a1a}.challenge-confirm-quit{background:#1a1a1a;color:#fff;border:none}.challenge-confirm-quit:hover{opacity:.88}.result-card{background:#fff;border-radius:12px;padding:24px 32px;display:flex;flex-direction:column;align-items:center;gap:12px;min-width:200px}.result-icon{font-size:2rem;font-weight:800}.result-card--solved .result-icon{color:#2e7d32}.result-card--failed .result-icon,.result-card--timeout .result-icon{color:#d32f2f}.result-text{font-size:1.1rem;font-weight:700}.result-rating{font-size:1rem;font-weight:700}.result-actions{display:flex;gap:10px;margin-top:8px}.btn-next{padding:8px 20px;background:#1a1a1a;color:#fff;border:none;border-radius:6px;font-size:.9rem;font-weight:600;cursor:pointer}.btn-next:hover{opacity:.85}.btn-next:disabled,.btn-quit:disabled,.btn-challenge-back:disabled,.btn-review-back:disabled,.btn-reset-review:disabled,.btn-export:disabled{opacity:.5;cursor:default}.btn-quit{padding:8px 20px;background:none;color:#666;border:1px solid #ccc;border-radius:6px;font-size:.9rem;cursor:pointer}.btn-quit:hover{border-color:#1a1a1a;color:#1a1a1a}.result-puzzle-stats{display:flex;flex-direction:column;align-items:center;gap:2px;font-size:.8rem;color:#888}.result-hint{font-size:.82rem;color:#666;font-weight:600}.result-error{max-width:240px;text-align:center;font-size:.78rem;line-height:1.4;color:#d32f2f}.result-correct{color:#2e7d32}.result-wrong{color:#d32f2f}.history-container{width:100%;max-width:420px;display:flex;flex-direction:column;gap:12px}.history-header{display:flex;align-items:center;gap:12px}.history-back{background:none;border:none;font-size:.9rem;color:#666;cursor:pointer;padding:4px 0}.history-back:hover{color:#1a1a1a}.history-title{font-size:1rem;font-weight:700}.history-loading,.history-empty{text-align:center;color:#999;padding:40px 0;font-size:.9rem}.history-list{display:flex;flex-direction:column;gap:4px}.history-item{display:flex;align-items:center;gap:10px;padding:8px 12px;border:1px solid #e8e8e8;border-radius:6px;background:#fff;cursor:pointer;font-size:.85rem;text-align:left;transition:border-color .15s}.history-item:hover{border-color:#1a1a1a}.history-icon{font-weight:800;font-size:1rem;width:20px;text-align:center}.history-correct .history-icon{color:#2e7d32}.history-wrong .history-icon{color:#d32f2f}.history-empties{font-weight:600;min-width:32px}.history-difficulty{color:#888;min-width:28px}.history-delta{font-weight:700;min-width:36px;text-align:right}.rating-up{color:#2e7d32}.rating-down{color:#d32f2f}.history-date{color:#aaa;font-size:.75rem;margin-left:auto}.review-container{display:flex;flex-direction:column;align-items:center;gap:12px}.review-header{display:flex;flex-direction:column;gap:8px;width:100%;max-width:420px}.review-info{display:flex;gap:10px;flex-wrap:wrap;row-gap:8px;font-size:.8rem;color:#666}.review-info span{background:#f0f0f0;padding:2px 8px;border-radius:8px;font-weight:600;white-space:nowrap}.review-solving{color:#999;font-size:.85rem}.review-actions{display:flex;gap:8px;width:100%;flex-wrap:nowrap}.review-actions>button{flex:1 1 0;min-width:0;white-space:nowrap;box-sizing:border-box}.btn-toggle-scores{padding:6px 16px;background:none;border:1.5px solid #1a1a1a;border-radius:6px;font-size:.85rem;font-weight:600;cursor:pointer;color:#1a1a1a;transition:all .15s}.btn-toggle-scores:hover,.btn-toggle-scores.btn-active{background:#1a1a1a;color:#fff}.btn-reset-review{padding:6px 16px;background:none;border:1px solid #ccc;border-radius:6px;font-size:.85rem;color:#666;cursor:pointer;transition:all .15s}.btn-reset-review:hover{border-color:#1a1a1a;color:#1a1a1a}.btn-export{padding:6px 16px;background:none;border:1px solid #ccc;border-radius:6px;font-size:.85rem;color:#666;cursor:pointer;transition:all .15s}.btn-export:hover{border-color:#1a1a1a;color:#1a1a1a}.btn-export:disabled{opacity:.4;cursor:default}.history-stats{color:#999;font-size:.75rem;white-space:nowrap}.review-step-nav{display:flex;gap:8px}.review-step-nav .practice-nav-btn{width:44px;height:36px;font-size:1.1rem}.history-pagination{display:flex;align-items:center;justify-content:center;gap:6px;padding:8px 0}.history-pagination .practice-nav-btn{width:40px;height:34px;font-size:1rem}.history-page-info{font-size:.8rem;color:#888;min-width:60px;text-align:center}@media(max-width:520px){.review-actions{gap:6px}.review-actions>button{padding-left:0;padding-right:0;font-size:.78rem}}.profile-overlay{position:fixed;inset:0;background:#0000007a;display:flex;align-items:center;justify-content:center;z-index:120;padding:16px}.profile-card{width:min(100%,620px);max-height:88vh;overflow-y:auto;background:#fff;border-radius:18px;box-shadow:0 24px 54px #00000038}.profile-header{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;padding:20px 22px 14px;border-bottom:1px solid #ececec}.profile-header h2{margin:0;font-size:1.2rem;font-weight:800}.profile-subtitle{margin:6px 0 0;font-size:.86rem;color:#777}.profile-close{border:none;background:none;font-size:1.4rem;color:#999;cursor:pointer;line-height:1}.profile-body{padding:18px 22px 22px}.profile-empty{min-height:200px;display:flex;align-items:center;justify-content:center;color:#888}.profile-stats-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.profile-stat-card{border:1px solid #ece8df;border-radius:12px;padding:12px 14px;background:#fbfaf7;display:flex;flex-direction:column;gap:4px}.profile-stat-label{font-size:.76rem;color:#8b8579;font-weight:700}.profile-stat-card strong{font-size:1rem;color:#1a1a1a}.profile-meta-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:14px;font-size:.82rem;color:#777}.profile-field-group{display:flex;flex-direction:column;gap:8px;margin-top:16px}.profile-label{font-size:.86rem;font-weight:700;color:#333}.profile-input,.profile-textarea,.profile-readonly{width:100%;box-sizing:border-box;border:1px solid #d7d7d7;border-radius:10px;padding:10px 12px;font-size:.92rem;color:#222;background:#fff}.profile-textarea{min-height:110px;resize:vertical;font-family:inherit}.profile-readonly{background:#fafafa}.profile-readonly--multiline{line-height:1.7;white-space:pre-line}.profile-helper{font-size:.78rem;line-height:1.5;color:#9b9b9b}.profile-footer{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:20px}.profile-feedback{flex:1;min-height:20px}.profile-error{font-size:.82rem;color:#d32f2f}.profile-saved{font-size:.82rem;color:#2e7d32}.profile-actions{display:flex;gap:10px}.profile-btn{border-radius:8px;padding:9px 18px;font-size:.88rem;font-weight:700;cursor:pointer}.profile-btn--primary{border:none;background:#1a1a1a;color:#fff}.profile-btn--secondary{border:1px solid #ccc;background:#fff;color:#666}.profile-btn:disabled{opacity:.55;cursor:default}@media(max-width:560px){.profile-stats-grid{grid-template-columns:1fr}.profile-footer{flex-direction:column;align-items:stretch}.profile-actions{width:100%}.profile-btn{flex:1}}.lb-container{width:100%;max-width:620px;display:flex;flex-direction:column;gap:12px}.lb-header{display:flex;align-items:center;gap:12px}.lb-title{font-size:1rem;font-weight:700}.lb-loading,.lb-empty{text-align:center;color:#999;padding:40px 0;font-size:.9rem}.lb-table{display:flex;flex-direction:column;gap:2px}.lb-row{display:flex;align-items:center;padding:8px 12px;border-radius:6px;background:#fff;font-size:.85rem;width:100%;border:1px solid transparent;text-align:left;appearance:none;color:inherit}.lb-row--header{background:transparent;font-weight:700;font-size:.75rem;color:#888;text-transform:uppercase;letter-spacing:.5px;padding:4px 12px}.lb-col-rank{width:28px;font-weight:700;color:#999;text-align:center;flex-shrink:0}.lb-col-name{flex:1;min-width:0;font-weight:600;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lb-col-realname{width:118px;flex-shrink:0;margin-right:10px;color:#666;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lb-name--gray{color:#999}.lb-name--green{color:#18831e}.lb-name--purple{color:#724bff}.lb-name--gold{color:#e7c52b}.lb-name--red{color:#cf1919}.lb-name--legendary{color:#cf1919;text-decoration:underline}.lb-col-rating{min-width:90px;text-align:center;font-weight:600;font-variant-numeric:tabular-nums;margin-right:12px}.lb-col-winrate{min-width:100px;text-align:center;color:#666;font-variant-numeric:tabular-nums}.lb-name--bold{font-weight:1000;font-size:.9rem}.lb-row--top3 .lb-col-rank{color:#1a1a1a;font-weight:1000;font-size:.95rem}.lb-row--top3{background:#fafafa;border:1px solid #e0e0e0}.lb-row:not(.lb-row--header){cursor:pointer}.lb-row:not(.lb-row--header):hover{border-color:#d7d7d7}@media(max-width:560px){.lb-row{padding:8px;font-size:.78rem}.lb-col-realname{width:82px;margin-right:6px}.lb-col-rating{min-width:78px;margin-right:6px}.lb-col-winrate{min-width:84px}}.help-overlay{position:fixed;inset:0;background:#00000080;display:flex;align-items:center;justify-content:center;z-index:100;padding:16px}.help-card{background:#fff;border-radius:12px;max-width:420px;width:100%;max-height:80vh;display:flex;flex-direction:column;overflow:hidden}.help-header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px 8px}.help-header h2{font-size:1.1rem;font-weight:700}.help-close{background:none;border:none;font-size:1.5rem;cursor:pointer;color:#999;line-height:1}.help-tabs{display:flex;gap:0;padding:0 20px;border-bottom:1px solid #eee}.help-tabs button{flex:1;padding:8px 0;border:none;background:none;font-size:.85rem;font-weight:600;color:#999;cursor:pointer;border-bottom:2px solid transparent}.help-tabs button.active{color:#1a1a1a;border-bottom-color:#1a1a1a}.help-body{padding:16px 20px;overflow-y:auto;font-size:.85rem;line-height:1.6;color:#333}.help-body h3{font-size:.9rem;font-weight:700;margin:12px 0 6px;color:#1a1a1a}.help-body h3:first-child{margin-top:0}.help-body ul{padding-left:18px;margin:0 0 8px}.help-body li{margin-bottom:3px}.help-rank-table{width:100%;border-collapse:collapse;margin:6px 0 12px;font-size:.82rem}.help-rank-table th,.help-rank-table td{padding:4px 8px;border:1px solid #eee;text-align:center}.help-rank-table th{background:#f5f5f5;font-weight:600}.menu-broadcast-bar{width:100%;display:flex;align-items:center;gap:10px;min-height:26px;overflow:hidden}.menu-broadcast-icon{width:16px;height:16px;flex-shrink:0;opacity:.9}.menu-broadcast-icon svg{width:100%;height:100%;display:block}.menu-broadcast-viewport{position:relative;flex:1;min-width:0;overflow:hidden;height:24px}.menu-broadcast-track{position:absolute;left:0;top:0;white-space:nowrap;will-change:transform;animation-name:menu-broadcast-marquee;animation-timing-function:linear;animation-fill-mode:forwards;animation-iteration-count:1;font-size:.88rem;font-weight:600;line-height:24px}.menu-broadcast-track span{display:inline-block;padding-right:32px}@keyframes menu-broadcast-marquee{0%{transform:translate(100%)}to{transform:translate(calc(-100% - 48px))}}@media(max-width:520px){.menu-broadcast-bar{gap:6px;min-height:24px}}.practice-menu{width:100%;max-width:480px}.practice-header{display:flex;align-items:center;gap:12px;margin-bottom:20px}.practice-title{font-size:1.1rem;font-weight:700;color:#1a1a1a}.practice-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}.practice-grid--sub{grid-template-columns:repeat(2,1fr)}.practice-btn{display:flex;flex-direction:column;align-items:center;gap:4px;padding:14px 8px;border:2px solid #ddd;border-radius:10px;background:#fff;cursor:pointer;transition:all .15s}.practice-btn:hover:not(:disabled){border-color:#1a1a1a;transform:translateY(-1px)}.practice-btn--done{border-color:#4caf50;background:#f1f8e9}.practice-btn--empty{opacity:.35;cursor:default}.practice-btn-label{font-size:.9rem;font-weight:600;color:#333}.practice-btn-count{font-size:.75rem;color:#888;font-variant-numeric:tabular-nums}.practice-btn--sub{padding:12px}.practice-btn--sub .practice-btn-label{font-family:monospace;font-size:.95rem}.practice-empty{grid-column:1 / -1;text-align:center;color:#999;padding:32px}.practice-play{display:flex;flex-direction:column;align-items:center;gap:10px;width:100%;max-width:480px}.practice-play-header{display:flex;align-items:center;gap:12px;width:100%}.practice-play-progress{font-size:.9rem;font-weight:600;color:#555;font-variant-numeric:tabular-nums}.practice-solved-badge{font-size:.75rem;font-weight:600;color:#4caf50;border:1px solid #4caf50;border-radius:999px;padding:2px 8px}.practice-top-nav{width:100%;display:grid;grid-template-columns:auto auto minmax(0,1fr) auto auto;align-items:center;gap:8px}.practice-play-info{display:flex;align-items:center;justify-content:center;gap:10px;min-width:0;font-size:.92rem;color:#555;font-weight:600}.practice-inline-nav-btn{border:none;background:none;color:#333;font-size:1.2rem;font-weight:700;line-height:1;padding:4px 2px;min-width:24px;cursor:pointer;transition:color .15s ease,opacity .15s ease,transform .15s ease}.practice-inline-nav-btn:hover:not(:disabled){color:#000;transform:translateY(-1px)}.practice-inline-nav-btn:disabled{color:#c7c7c7;cursor:default;transform:none}.side-indicator{display:flex;align-items:center;gap:6px;padding:3px 12px;border-radius:14px;font-weight:700;font-size:.85rem;flex-shrink:0}.side-indicator--black{background:#1a1a1a;color:#fff}.side-indicator--white{background:#fff;color:#1a1a1a;border:2px solid #bbb}.side-piece{width:14px;height:14px;border-radius:50%;flex-shrink:0}.side-indicator--black .side-piece{background:radial-gradient(circle at 35% 35%,#555,#111)}.side-indicator--white .side-piece{background:radial-gradient(circle at 35% 35%,#fff,#ccc);border:1px solid #aaa}.practice-result{display:flex;align-items:center;gap:12px;padding:8px 0}.practice-result--correct{font-weight:700;color:#4caf50;font-size:1rem}.practice-result--wrong{font-weight:700;color:#e53935;font-size:1rem}.practice-review-nav{display:flex;gap:8px;padding-top:2px}.practice-review-nav-btn{width:44px;height:36px;border:1px solid #d3d3d3;border-radius:8px;background:#fff;color:#555;font-size:1.1rem;font-weight:700;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all .15s ease}.practice-review-nav-btn:hover:not(:disabled){border-color:#1a1a1a;color:#1a1a1a;background:#f6f6f6}.practice-review-nav-btn:disabled{border-color:#e4e4e4;background:#f4f4f4;color:#b8b8b8;cursor:default}.practice-extra-actions{width:100%;display:flex;justify-content:center;gap:10px;flex-wrap:wrap}.practice-action-btn{min-width:104px;height:40px;border:1px solid #cfcfcf;border-radius:8px;background:#fff;color:#333;font-size:.88rem;font-weight:600;cursor:pointer;transition:all .15s ease}.practice-action-btn:hover:not(:disabled){border-color:#1a1a1a;background:#f7f7f7}.practice-action-btn:disabled{border-color:#e2e2e2;background:#f3f3f3;color:#a9a9a9;cursor:default}.practice-action-btn--active{border-color:#1a1a1a;background:#1a1a1a;color:#fff}.practice-action-btn--active:hover:not(:disabled){background:#2a2a2a;border-color:#2a2a2a}@media(max-width:480px){.practice-top-nav{gap:6px}.practice-play-info{gap:8px;font-size:.88rem}.practice-inline-nav-btn{font-size:1.1rem}.practice-extra-actions{gap:8px}.practice-action-btn{min-width:96px}}.teaching-menu{width:100%;max-width:520px}.teaching-header{display:flex;align-items:center;gap:12px;margin-bottom:12px}.teaching-back{background:none;border:none;padding:4px 0;color:#666;font-size:.9rem;cursor:pointer}.teaching-back:hover{color:#1a1a1a}.teaching-title{margin:0;font-size:1.08rem;font-weight:700;color:#1a1a1a}.teaching-intro{margin:0 0 16px;color:#8d8d8d;font-size:.86rem;line-height:1.5}.teaching-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px}.teaching-btn{min-height:104px;padding:16px 14px;border:2px solid #ddd;border-radius:12px;background:#fff;display:flex;flex-direction:column;align-items:flex-start;justify-content:space-between;gap:8px;text-align:left;cursor:pointer;transition:border-color .15s ease,transform .15s ease}.teaching-btn:hover{border-color:#1a1a1a;transform:translateY(-1px)}.teaching-btn-tag{color:#9a9a9a;font-size:.72rem;letter-spacing:.3px}.teaching-btn-label{color:#1a1a1a;font-size:1rem;font-weight:700;line-height:1.45}.teaching-btn-hint{color:#a3a3a3;font-size:.78rem}@media(max-width:440px){.teaching-grid{grid-template-columns:1fr}.teaching-btn{min-height:92px}}.announcement-overlay{position:fixed;inset:0;background:#00000073;display:flex;align-items:center;justify-content:center;z-index:100;padding:16px}.announcement-card{background:#fff;border-radius:18px;max-width:980px;width:100%;max-height:88vh;overflow:hidden;box-shadow:0 22px 50px #00000038}.announcement-header{display:flex;align-items:center;justify-content:space-between;padding:18px 22px 14px;border-bottom:1px solid #ece8df;background:linear-gradient(135deg,#f8f3e7,#fffdfa)}.announcement-header-main{display:flex;align-items:center;gap:10px}.announcement-header h2{font-size:1.1rem;font-weight:700;margin:0}.announcement-header-badge{display:inline-flex;align-items:center;justify-content:center;padding:3px 9px;border-radius:999px;font-size:.75rem;font-weight:700;color:#fff;background:#b93f2f}.announcement-close{background:none;border:none;font-size:1.3rem;cursor:pointer;color:#999;padding:0 4px;line-height:1}.announcement-close:hover{color:#1a1a1a}.announcement-body{display:grid;grid-template-columns:320px 1fr;min-height:480px;max-height:calc(88vh - 70px)}.announcement-sidebar{border-right:1px solid #ece8df;padding:18px 14px 18px 18px;overflow-y:auto;background:#fbfaf7}.announcement-section+.announcement-section{margin-top:18px}.announcement-section-title{font-size:.74rem;font-weight:700;letter-spacing:.08em;color:#9a7a47;margin-bottom:10px}.announcement-date{font-size:.75rem;color:#999}.announcement-list-item{width:100%;text-align:left;border:1px solid #ece8df;border-radius:12px;padding:12px 13px;background:#fff;cursor:pointer;transition:border-color .15s,transform .15s,box-shadow .15s}.announcement-list-item+.announcement-list-item{margin-top:10px}.announcement-list-item:hover{border-color:#c7a46b;transform:translateY(-1px);box-shadow:0 8px 18px #a1814f1f}.announcement-list-item--active{border-color:#8e6234;background:#fff8ee}.announcement-list-top{display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:8px}.announcement-unread-tag,.announcement-pin{display:inline-flex;align-items:center;justify-content:center;border-radius:999px;padding:2px 8px;font-size:.7rem;font-weight:700}.announcement-unread-tag{color:#b93f2f;background:#fdecea}.announcement-pin{color:#8e6234;background:#f8edd7}.announcement-title-row{display:flex;align-items:flex-start;gap:8px;margin-bottom:8px}.announcement-title{flex:1;font-size:.93rem;font-weight:700;color:#1a1a1a}.announcement-summary{margin:0;font-size:.82rem;line-height:1.5;color:#6a665d}.announcement-detail{display:flex;flex-direction:column;min-width:0;overflow-y:auto;padding:18px 22px 22px}.announcement-detail-toolbar{display:none;margin-bottom:12px}.announcement-back{border:none;background:none;color:#8e6234;font-size:.86rem;font-weight:700;cursor:pointer;padding:0}.announcement-article-meta{display:flex;align-items:center;gap:8px;margin-bottom:12px}.announcement-article-title{margin:0 0 12px;font-size:1.25rem;line-height:1.35;color:#1f1b16}.announcement-article-summary{margin:0 0 18px;font-size:.92rem;line-height:1.65;color:#685f52;padding-left:12px;border-left:3px solid #d7c09d}.announcement-content{font-size:.92rem;color:#444;line-height:1.8;margin:0;white-space:pre-line}.btn-announcement-dot{position:relative}.btn-announcement-count{position:absolute;top:-8px;right:-10px;min-width:18px;height:18px;padding:0 5px;border-radius:999px;background:#b93f2f;color:#fff;font-size:.7rem;font-weight:700;line-height:18px;text-align:center}@media(max-width:520px){.btn-announcement-count{top:-6px;right:-6px;min-width:16px;height:16px;padding:0 4px;font-size:.64rem;line-height:16px}}.announcement-empty{display:flex;align-items:center;justify-content:center;min-height:240px;width:100%;font-size:.92rem;color:#857b6e}@media(max-width:760px){.announcement-card{max-width:100%;max-height:92vh}.announcement-body{display:block;max-height:calc(92vh - 70px)}.announcement-sidebar,.announcement-detail{max-height:calc(92vh - 70px)}.announcement-sidebar{border-right:0;padding-right:18px}.announcement-detail-toolbar{display:block}.announcement-sidebar--hidden-mobile,.announcement-detail--hidden-mobile{display:none}}.required-realname-overlay{position:fixed;inset:0;z-index:130;display:flex;align-items:center;justify-content:center;padding:16px;background:#0000007a}.required-realname-card{width:min(100%,420px);background:#fff;border-radius:16px;padding:22px;box-shadow:0 24px 54px #00000038}.required-realname-card h2{margin:0 0 10px;font-size:1.15rem;font-weight:800;color:#1a1a1a}.required-realname-desc{margin:0 0 18px;font-size:.86rem;line-height:1.65;color:#666}.required-realname-label{display:block;margin-bottom:8px;font-size:.86rem;font-weight:700;color:#333}.required-realname-input{width:100%;box-sizing:border-box;border:1.5px solid #ccc;border-radius:8px;padding:10px 12px;font-size:.95rem;color:#1a1a1a;outline:none}.required-realname-input:focus{border-color:#1a1a1a}.required-realname-error{margin-top:10px;font-size:.82rem;color:#d32f2f}.required-realname-actions{display:flex;gap:10px;justify-content:flex-end;margin-top:20px}.required-realname-btn{border-radius:8px;padding:9px 18px;font-size:.88rem;font-weight:700;cursor:pointer}.required-realname-btn--primary{border:none;background:#1a1a1a;color:#fff}.required-realname-btn--secondary{border:1px solid #ccc;background:#fff;color:#666}.required-realname-btn:disabled{opacity:.55;cursor:default}.app{min-height:100svh;display:flex;flex-direction:column;align-items:center}.main{flex:1;display:flex;align-items:flex-start;justify-content:center;padding:8px 16px 32px;width:100%;box-sizing:border-box}.loading{display:flex;align-items:center;justify-content:center;min-height:60svh;color:#999;font-size:.95rem}.menu-wrapper{display:flex;flex-direction:column;align-items:center;gap:12px;padding-top:10px;width:min(100%,460px)}.menu-broadcast-slot{width:100%;min-height:28px}.menu-main-buttons{display:flex;flex-direction:column;align-items:center;gap:12px;margin-top:4px;margin-bottom:-4px;width:100%}.menu-main-btn{width:min(100%,320px);padding:18px 56px;border:2px solid #1a1a1a;border-radius:12px;font-size:1.1rem;font-weight:700;cursor:pointer;transition:all .15s;letter-spacing:1px}.menu-main-btn--practice{background:#fff;color:#1a1a1a}.menu-main-btn--practice:hover{background:#f0f0f0;transform:translateY(-2px)}.menu-main-btn:disabled{opacity:.4;cursor:default;transform:none}.menu-links{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;width:100%}.menu-toggles{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;width:100%}.btn-history{background:none;border:1px solid #ccc;border-radius:6px;padding:7px 14px;font-size:.8rem;color:#666;cursor:pointer;transition:all .15s;white-space:nowrap}.btn-history:hover{border-color:#1a1a1a;color:#1a1a1a}.app-footer{padding:16px 0 24px;text-align:center;font-size:.75rem;color:#bbb;letter-spacing:.5px}.site-traffic-badge{position:fixed;left:12px;bottom:12px;display:flex;flex-direction:column;gap:2px;color:#1a1a1a6b;font-size:.7rem;line-height:1.3;letter-spacing:.2px;pointer-events:none;z-index:20}.site-traffic-badge span{white-space:nowrap}.btn-delete-account{background:none;border:none;color:#bbb;font-size:.75rem;cursor:pointer;text-decoration:underline}.btn-delete-account:hover{color:#e53935}.account-actions{margin-top:24px;display:flex;align-items:center;justify-content:center;gap:20px;flex-wrap:wrap}.btn-deep-think{background:none;border:1px solid #ccc;border-radius:8px;padding:8px 20px;font-size:.85rem;color:#999;cursor:pointer;transition:all .15s;font-weight:600;white-space:nowrap}.btn-deep-think:hover{border-color:#1a1a1a;color:#1a1a1a}.btn-deep-think:disabled{opacity:.45;cursor:default;border-color:#ddd;color:#aaa}.btn-deep-think:disabled:hover{border-color:#ddd;color:#aaa}.btn-deep-think--active{background:#1a1a1a;color:#fff;border-color:#1a1a1a}.btn-deep-think--active:hover{opacity:.85;color:#fff}.coming-soon-overlay{position:fixed;inset:0;background:#0000006b;display:flex;align-items:center;justify-content:center;padding:20px;z-index:1000}.coming-soon-card{width:min(100%,360px);background:#fffaf0;border:1px solid #d7c79d;border-radius:16px;box-shadow:0 18px 48px #0003;padding:24px 22px 20px;text-align:center}.coming-soon-card h2{margin:0 0 10px;font-size:1.25rem;color:#5e4b20}.coming-soon-card p{margin:0;color:#6f6450;line-height:1.6}.coming-soon-close{margin-top:18px;padding:9px 22px;border:1px solid #bfa46a;border-radius:999px;background:#f2e4bd;color:#5e4b20;font-size:.92rem;font-weight:700;cursor:pointer;transition:transform .15s ease,background .15s ease}.coming-soon-close:hover{background:#ead8a4;transform:translateY(-1px)}@media(max-width:520px){.main{padding:8px 10px 28px}.menu-main-btn{width:100%;padding:16px 24px}.menu-broadcast-slot{min-height:24px}.menu-links,.menu-toggles{flex-wrap:nowrap;justify-content:space-between;gap:6px}.menu-links .btn-history,.menu-toggles .btn-deep-think{flex:1 1 0;min-width:0;text-align:center}.menu-links .btn-history{padding:7px 8px;font-size:.74rem}.menu-toggles .btn-deep-think{padding:8px 10px;font-size:.76rem}.site-traffic-badge{left:8px;bottom:8px;font-size:.66rem}}@media(max-width:380px){.menu-links,.menu-toggles{gap:4px}.menu-links .btn-history{padding:7px 6px;font-size:.71rem}.menu-toggles .btn-deep-think{padding:8px;font-size:.72rem}}