*{box-sizing:border-box;margin:0;padding:0}:root{--primary:#1677ff;--success:#00b578;--danger:#ff3141;--warning:#ff8f1f;--text:#333;--text-light:#666;--bg:#f5f5f5;--card-bg:#fff;--border:#eee}body{background:var(--bg);color:var(--text);-webkit-tap-highlight-color:transparent;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}.page{max-width:600px;margin:0 auto;padding:16px 16px 80px}.page-header{align-items:center;gap:10px;margin-bottom:8px;padding:8px 0;display:flex}.page-header h2{font-size:20px;font-weight:600}.back-btn{cursor:pointer;color:var(--primary);background:0 0;border:none;padding:4px;font-size:22px}.card{background:var(--card-bg);border-radius:12px;margin-bottom:8px;padding:12px;box-shadow:0 1px 3px #0000000d}.btn{cursor:pointer;border:none;border-radius:8px;justify-content:center;align-items:center;padding:10px 20px;font-size:16px;font-weight:500;transition:opacity .2s;display:inline-flex}.btn:active{opacity:.7}.btn-primary{background:var(--primary);color:#fff}.btn-success{background:var(--success);color:#fff}.btn-danger{background:var(--danger);color:#fff}.btn-outline{border:1px solid var(--border);color:var(--text);background:0 0}.btn-block{width:100%}.btn-sm{padding:6px 12px;font-size:14px}.input{border:1px solid var(--border);border-radius:8px;outline:none;width:100%;padding:10px 12px;font-size:16px;transition:border-color .2s}.input:focus{border-color:var(--primary)}.textarea{border:1px solid var(--border);resize:vertical;border-radius:8px;outline:none;width:100%;min-height:120px;padding:10px 12px;font-family:monospace;font-size:16px}.textarea:focus{border-color:var(--primary)}.form-group{margin-bottom:10px}.form-group label{color:var(--text-light);margin-bottom:4px;font-size:14px;display:block}.bottom-nav{border-top:1px solid var(--border);padding:8px 0 env(safe-area-inset-bottom,8px);z-index:100;background:#fff;display:flex;position:fixed;bottom:0;left:0;right:0}.bottom-nav a{text-align:center;color:var(--text-light);flex:1;padding:4px 0;font-size:12px;text-decoration:none}.bottom-nav a.active{color:var(--primary)}.bottom-nav a .icon{font-size:22px;display:block}.empty-tip{text-align:center;color:var(--text-light);padding:40px 20px;font-size:14px}.word-card{text-align:center;padding:32px 16px}.word-card .english{color:var(--primary);word-break:break-all;margin-bottom:16px;font-size:36px;font-weight:700}.word-card .chinese{color:var(--text);font-size:36px}.word-card .phonetic{color:var(--text-light);margin-bottom:16px;font-family:Segoe UI,Arial Unicode MS,sans-serif;font-size:36px}.action-row{justify-content:center;gap:10px;margin-top:16px;display:flex}.progress-bar{text-align:center;color:var(--text-light);margin-bottom:10px;font-size:14px}.masked-word{flex-wrap:wrap;justify-content:center;align-items:flex-end;gap:10px 6px;min-height:54px;margin-bottom:12px;font-size:32px;font-weight:700;display:flex}.masked-word .cell{width:40px;height:50px;color:var(--text);border-bottom:3px solid var(--primary);justify-content:center;align-items:center;font-size:28px;font-weight:700;display:inline-flex}.masked-word .gap{pointer-events:none;width:18px;height:50px}.masked-word .slot{width:40px;height:50px;color:var(--text);border-bottom:3px solid var(--primary);cursor:pointer;-webkit-user-select:none;user-select:none;touch-action:manipulation;background:0 0;border-radius:6px 6px 0 0;outline:none;justify-content:center;align-items:center;font-size:28px;font-weight:700;display:inline-flex}.masked-word .slot.active{background:#1677ff1f}.masked-word .slot.correct{border-bottom-color:var(--success);color:var(--success)}.masked-word .slot.wrong{border-bottom-color:var(--danger);color:var(--danger);animation:.3s shake}.masked-word .slot.wrong.active{background:#ff31411a}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-4px)}75%{transform:translate(4px)}}.page.with-keyboard{padding-bottom:calc(250px + env(safe-area-inset-bottom,0px))}.letter-keyboard{z-index:300;border-top:1px solid var(--border);width:100%;padding:10px 6px calc(10px + env(safe-area-inset-bottom,0px));-webkit-user-select:none;user-select:none;background:#f7f8fa;position:fixed;bottom:0;left:0;right:0;box-shadow:0 -2px 10px #0000000f}.letter-keyboard .kb-row{gap:6px;margin-bottom:8px;display:flex}.letter-keyboard .kb-row:last-child{margin-bottom:0}.letter-keyboard .kb-key{height:54px;color:var(--text);cursor:pointer;touch-action:manipulation;background:#fff;border:none;border-radius:8px;flex:1;justify-content:center;align-items:center;padding:0;font-family:inherit;font-size:22px;font-weight:500;transition:background-color 80ms,color 80ms;display:inline-flex;box-shadow:0 1px 2px #00000014}.letter-keyboard .kb-key:active,.letter-keyboard .kb-key.pressed{background:var(--primary);color:#fff}.letter-keyboard .kb-key.kb-ctrl{color:var(--text);background:#eceef1;flex:1.6;font-size:16px}.letter-keyboard .kb-key.kb-ctrl:active,.letter-keyboard .kb-key.kb-ctrl.pressed{background:var(--danger);color:#fff}.slider-group{padding:0 8px}.slider-group input[type=range]{width:100%;margin:8px 0}.slider-value{text-align:center;color:var(--primary);font-size:24px;font-weight:600}.stats-row{gap:8px;display:flex}.stats-item{text-align:center;background:var(--bg);border-radius:8px;flex:1;padding:12px 4px}.stats-num{color:var(--primary);font-size:24px;font-weight:700}.stats-label{color:var(--text-light);margin-top:4px;font-size:12px}