:root{color-scheme:light;--bg: #f7f9fb;--surface: #f7f9fb;--surface-bright: #f7f9fb;--surface-container-lowest: #ffffff;--surface-container-low: #f2f4f6;--surface-container: #eceef0;--surface-container-high: #e6e8ea;--surface-container-highest: #e0e3e5;--surface-variant: #e0e3e5;--fg: #191c1e;--on-surface: #191c1e;--on-surface-variant: #45464d;--outline: #76777d;--outline-variant: #c6c6cd;--inverse-surface: #2d3133;--inverse-on-surface: #eff1f3;--primary: #000000;--on-primary: #ffffff;--primary-container: #131b2e;--on-primary-container: #7c839b;--secondary: #505f76;--secondary-container: #d0e1fb;--tone-1: #dc2626;--tone-2: #ea580c;--tone-3: #16a34a;--tone-4: #2563eb;--tone-5: #6b7280;--ok: #16a34a;--bad: #dc2626;--warn: #ea580c;--accent: #2563eb;--hsk-1: #16a34a;--hsk-2: #2563eb;--hsk-3: #7c3aed;--hsk-4: #ea580c;--hsk-5: #dc2626;--hsk-6: #9333ea;--hsk-extra: #6b7280;--unit: 4px;--stack-gap: 16px;--card-gap: 24px;--container-padding: 20px;--touch-target: 48px;--r-sm: 2px;--r-default: 4px;--r-md: 6px;--r-lg: 8px;--r-xl: 12px;--r-pill: 999px;--shadow-active-card: 0 4px 24px rgba(0, 0, 0, .08);--shadow-soft: 0 4px 24px rgba(0, 0, 0, .02);--font-ui: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;--font-han: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", serif;--font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body{margin:0;padding:0;height:100%}body{font-family:var(--font-ui);font-size:16px;line-height:24px;font-weight:400;background:var(--bg);color:var(--fg);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;touch-action:manipulation}#app{display:flex;flex-direction:column;min-height:100dvh;max-width:640px;margin:0 auto;padding-top:env(safe-area-inset-top)}.han{font-family:var(--font-han);font-weight:500;letter-spacing:.01em}.topbar{position:sticky;top:0;z-index:40;height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 var(--container-padding);background:var(--surface);border-bottom:1px solid var(--outline-variant)}.topbar-icon-btn{width:var(--touch-target);height:var(--touch-target);display:flex;align-items:center;justify-content:center;border:none;background:transparent;border-radius:var(--r-pill);color:var(--on-surface-variant);cursor:pointer;transition:background .15s,color .15s,transform .08s}.topbar-icon-btn:hover{background:var(--surface-container-high)}.topbar-icon-btn:active{transform:scale(.95)}.topbar-icon-btn .material-symbols-outlined{font-variation-settings:"FILL" 0;font-size:22px}.topbar-center{flex:1;display:flex;flex-direction:column;align-items:center;gap:4px}.topbar-title{font-size:13px;font-weight:600;letter-spacing:.04em;text-transform:uppercase;color:var(--on-surface)}.topbar-progress{display:flex;align-items:center;gap:8px;font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--on-surface-variant)}.progress-track{width:96px;height:4px;background:var(--surface-container-highest);border-radius:var(--r-pill);overflow:hidden}.progress-fill{height:100%;background:var(--primary);border-radius:var(--r-pill);transition:width .3s ease-out}.main{flex:1;display:flex;flex-direction:column;gap:var(--stack-gap);padding:var(--card-gap) var(--container-padding);padding-bottom:calc(96px + env(safe-area-inset-bottom))}.card{background:var(--surface-container-lowest);border:1px solid var(--surface-variant);border-radius:var(--r-xl);padding:var(--stack-gap);display:flex;flex-direction:column;gap:12px}.card-active{box-shadow:var(--shadow-active-card);border-color:var(--outline-variant)}.card-tight{padding:12px var(--stack-gap);gap:8px}.section-label{font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.08em;text-transform:uppercase;color:var(--on-surface-variant);display:flex;align-items:center;gap:6px}.section-label .material-symbols-outlined{font-size:14px;font-variation-settings:"FILL" 0}.hero{display:flex;flex-direction:column;align-items:center;gap:12px;padding:8px 0}.hero-char{font-family:var(--font-han);font-weight:500;font-size:64px;line-height:72px;letter-spacing:.05em;color:var(--on-surface);text-align:center;user-select:none}@media (min-width: 640px){.hero-char{font-size:84px;line-height:100px}}.pinyin-row{display:flex;align-items:baseline;gap:8px;font-size:24px;font-weight:500;letter-spacing:.02em}.audio-btn{width:32px;height:32px;display:inline-flex;align-items:center;justify-content:center;border:none;background:transparent;color:var(--on-surface-variant);cursor:pointer;border-radius:var(--r-pill);transition:background .15s,color .15s}.audio-btn:hover{background:var(--surface-container-high);color:var(--primary)}.audio-btn .material-symbols-outlined{font-size:18px;font-variation-settings:"FILL" 0}.meaning{font-size:15px;line-height:22px;color:var(--on-surface-variant);text-align:center;max-width:360px}.tone-1{color:var(--tone-1)}.tone-2{color:var(--tone-2)}.tone-3{color:var(--tone-3)}.tone-4{color:var(--tone-4)}.tone-5{color:var(--tone-5)}.stroke-anim{display:flex;justify-content:center;padding:12px 0}.stroke-frame{width:192px;height:192px;border:1px solid var(--surface-variant);border-radius:var(--r-lg);background:var(--surface-container-low);position:relative;display:flex;align-items:center;justify-content:center;overflow:hidden}.stroke-frame:before,.stroke-frame:after{content:"";position:absolute;background:var(--outline-variant);opacity:.4}.stroke-frame:before{left:50%;top:0;bottom:0;width:1px}.stroke-frame:after{top:50%;left:0;right:0;height:1px}.radical-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}.radical-chip{background:var(--surface-container-low);border:1px solid var(--surface-variant);border-radius:var(--r-lg);padding:8px 12px;display:flex;align-items:center;gap:10px;font-size:14px;color:var(--on-surface-variant)}.radical-chip .han{font-size:24px;line-height:1;width:28px;text-align:center;color:var(--on-surface)}.example-block{background:var(--surface-container-low);border-radius:var(--r-lg);padding:var(--stack-gap);display:flex;flex-direction:column;gap:4px}.example-block .han{font-size:24px;line-height:32px}.example-block .pinyin{font-family:var(--font-mono);font-size:13px;color:var(--on-surface-variant);letter-spacing:.02em}.example-block .gloss{font-size:13px;font-style:italic;color:var(--on-surface-variant)}.memory-aid{font-size:14px;line-height:22px;color:var(--on-surface)}.memory-aid em{font-style:normal;font-size:11px;color:var(--on-surface-variant);margin-left:6px}.btn{font-family:inherit;font-size:15px;font-weight:600;letter-spacing:.01em;border:none;border-radius:var(--r-pill);padding:0 24px;height:var(--touch-target);min-height:var(--touch-target);cursor:pointer;background:var(--primary);color:var(--on-primary);transition:transform .08s,opacity .2s,background .15s;display:inline-flex;align-items:center;justify-content:center;gap:6px}.btn:hover{background:var(--inverse-surface)}.btn:active{transform:scale(.98)}.btn:disabled{opacity:.4;cursor:not-allowed}.btn-secondary{background:transparent;color:var(--on-surface-variant);border:1px solid var(--outline-variant)}.btn-secondary:hover{background:var(--surface-container-high);color:var(--on-surface)}.btn-ghost{background:transparent;color:var(--on-surface-variant);padding:0 16px}.btn-ghost:hover{background:var(--surface-container-high)}.btn-accent{background:var(--accent)}.btn-accent:hover{background:#1d4ed8}.btn-bad{background:var(--bad)}.btn-bad:hover{background:#b91c1c}.btn-warn{background:var(--warn)}.btn-warn:hover{background:#c2410c}.btn-ok{background:var(--ok)}.btn-ok:hover{background:#15803d}.bottom-bar{position:fixed;bottom:0;left:0;right:0;z-index:30;padding:12px var(--container-padding) calc(12px + env(safe-area-inset-bottom));background:#f7f9fbeb;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-top:1px solid var(--outline-variant);display:flex;justify-content:center}.bottom-bar-inner{width:100%;max-width:640px;display:flex;gap:8px;align-items:center}.bottom-bar .btn{flex:1}.rating-row{width:100%;display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.rate-btn{display:flex;flex-direction:column;align-items:center;justify-content:center;height:var(--touch-target);border:none;background:var(--surface-container);color:var(--on-surface-variant);border-radius:var(--r-lg);font-family:inherit;font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;cursor:pointer;gap:2px;transition:background .15s,color .15s,transform .08s}.rate-btn:hover{transform:translateY(-1px)}.rate-btn:active{transform:scale(.98)}.rate-btn .material-symbols-outlined{font-size:18px;font-variation-settings:"FILL" 0}.rate-btn-again:hover{background:#fdf2f2;color:var(--bad)}.rate-btn-hard:hover{background:#fff7ed;color:var(--warn)}.rate-btn-good:hover{background:#f0fdf4;color:var(--ok)}.rate-btn-easy:hover{background:#eff6ff;color:var(--accent)}.tile-row{display:flex;gap:10px;justify-content:center;padding:8px 0 16px;min-height:96px}.tile{width:88px;height:88px;background:var(--surface-container-lowest);border:1px solid var(--surface-variant);border-radius:var(--r-lg);display:flex;align-items:center;justify-content:center;font-family:var(--font-han);font-size:44px;font-weight:500;cursor:pointer;user-select:none;transition:transform .1s,border-color .15s,background .15s}.tile:hover{border-color:var(--outline-variant)}.tile:active{transform:scale(.94)}.tile.selected{background:var(--primary);color:var(--on-primary);border-color:var(--primary)}.tile.correct{border-color:var(--ok);color:var(--ok)}.tile.disabled{opacity:.35;pointer-events:none}.sentence-card{background:var(--surface-container-lowest);border:1px solid var(--surface-variant);border-radius:var(--r-lg);padding:var(--stack-gap);display:flex;flex-direction:column;gap:8px}.sentence-line{font-family:var(--font-han);font-size:22px;line-height:32px;color:var(--on-surface)}.blank{display:inline-block;min-width:42px;height:32px;line-height:32px;text-align:center;border-bottom:2px solid var(--on-surface);margin:0 4px;vertical-align:-4px}.blank.empty{border-bottom-color:var(--outline-variant)}.blank.correct{color:var(--ok);border-bottom-color:var(--ok)}.blank.wrong{color:var(--bad);border-bottom-color:var(--bad)}.blank.disc-fail{color:var(--bad);border-bottom-color:var(--bad);text-decoration:line-through}.sentence-meta{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.pinyin-help{font-family:var(--font-mono);font-size:13px;color:var(--on-surface-variant);letter-spacing:.02em}.gloss-toggle{background:transparent;border:1px solid var(--outline-variant);border-radius:var(--r-default);padding:4px 10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--on-surface-variant);cursor:pointer}.gloss-toggle:hover{background:var(--surface-container-high)}.gloss-revealed{font-size:14px;font-style:italic;color:var(--on-surface-variant)}.pinyin-input{width:100%;font-family:var(--font-han);font-size:24px;text-align:center;padding:14px;border-radius:var(--r-lg);border:2px solid var(--surface-variant);background:var(--surface-container-lowest);outline:none;transition:border-color .15s,background .15s}.pinyin-input:focus{border-color:var(--accent)}.pinyin-input.correct{border-color:var(--ok);background:#f0fdf4}.pinyin-input.wrong{border-color:var(--bad);background:#fef2f2}.tone-buttons{width:100%;display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.tone-buttons .btn{font-family:var(--font-mono);font-size:13px;letter-spacing:.04em;padding:0;border-radius:var(--r-lg);color:#fff}.tone-buttons .tone-1-btn{background:var(--tone-1)}.tone-buttons .tone-2-btn{background:var(--tone-2)}.tone-buttons .tone-3-btn{background:var(--tone-3)}.tone-buttons .tone-4-btn{background:var(--tone-4)}.tone-buttons .tone-5-btn{background:var(--tone-5)}.feedback{font-size:13px;text-align:center;min-height:18px;color:var(--on-surface-variant)}.feedback.success{color:var(--ok)}.feedback.fail{color:var(--bad)}.done{text-align:center;padding:48px 24px;color:var(--on-surface-variant)}.done h2{font-size:24px;font-weight:600;margin:0 0 12px;color:var(--on-surface)}table.stats{width:100%;border-collapse:collapse;font-size:13px}table.stats th,table.stats td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--surface-variant)}table.stats td.num{text-align:right;font-variant-numeric:tabular-nums;font-family:var(--font-mono)}table.stats td.han{font-family:var(--font-han);font-size:18px}.settings-form{display:flex;flex-direction:column;gap:12px}.settings-form label{display:flex;flex-direction:column;gap:6px;font-size:13px;color:var(--on-surface-variant)}.settings-form input[type=text],.settings-form input[type=password],.settings-form input[type=number]{font-family:var(--font-ui);font-size:16px;padding:10px 14px;border-radius:var(--r-default);border:1px solid var(--outline-variant);background:var(--surface-container-lowest);outline:none;transition:border-color .15s}.settings-form input:focus{border-color:var(--accent)}.reader-text{display:flex;flex-direction:column;gap:8px}.reader-line{display:flex;flex-wrap:wrap;align-items:flex-end;padding:8px 12px;border-radius:var(--r-default);border-left:3px solid transparent;transition:background .15s,border-color .15s;cursor:pointer;row-gap:12px}.reader-line:hover{background:var(--surface-container-low)}.reader-line.active{background:var(--surface-container-low);border-left-color:var(--primary)}.reader-line-translation{font-size:13px;color:var(--on-surface-variant);font-style:italic;padding:4px 12px 0}.token{display:inline-flex;flex-direction:column;align-items:stretch;width:2.4em;min-height:2.6em;font-family:var(--font-han);font-size:22px;line-height:1;padding:0;cursor:pointer;transition:background .15s;text-align:center;ruby-position:over;overflow:hidden}.token>rt{display:block;font-family:var(--font-mono);font-size:9.5px;color:var(--on-surface-variant);letter-spacing:.01em;line-height:12px;height:12px;margin:0 0 6px;text-align:center;white-space:nowrap;overflow:hidden;text-overflow:clip;pointer-events:none}.token>rt.rt-spacer{visibility:hidden}.token:after{content:"";display:block;width:1.2em;margin:2px auto 0;border-bottom:2px solid transparent}.token.hsk-1:after{border-bottom-color:var(--hsk-1)}.token.hsk-2:after{border-bottom-color:var(--hsk-2)}.token.hsk-3:after{border-bottom-color:var(--hsk-3)}.token.hsk-4:after{border-bottom-color:var(--hsk-4)}.token.hsk-5:after{border-bottom-color:var(--hsk-5)}.token.hsk-6:after{border-bottom-color:var(--hsk-6)}.token.hsk-extra:after{border-bottom-color:var(--hsk-extra)}.token.unknown:after{border-bottom:2px dotted var(--hsk-extra)}.token:hover{background:var(--surface-container-high)}.token.hsk-full.hsk-1{background:#dcfce7}.token.hsk-full.hsk-2{background:#dbeafe}.token.hsk-full.hsk-3{background:#ede9fe}.token.hsk-full.hsk-4{background:#ffedd5}.token.hsk-full.hsk-5{background:#fee2e2}.token.hsk-full.hsk-6{background:#f3e8ff}.reader-lookup{position:fixed;left:0;right:0;bottom:0;z-index:50;background:var(--surface-container-lowest);border-top:1px solid var(--outline-variant);box-shadow:0 -8px 24px #00000014;padding:16px 20px calc(16px + env(safe-area-inset-bottom));display:flex;flex-direction:column;gap:8px;animation:slide-up .2s ease-out}@keyframes slide-up{0%{transform:translateY(100%)}to{transform:translateY(0)}}.reader-lookup .han{font-size:32px}.reader-lookup .pinyin{font-family:var(--font-mono);color:var(--accent)}.reader-lookup .hsk-chip{display:inline-flex;align-items:center;padding:2px 8px;border-radius:var(--r-pill);font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;background:var(--surface-container);color:var(--on-surface-variant)}.reader-controls{display:flex;gap:8px;flex-wrap:wrap}.reader-control{display:flex;flex-direction:column;gap:4px;font-family:var(--font-mono);font-size:10px;text-transform:uppercase;letter-spacing:.08em;color:var(--on-surface-variant)}.reader-control select{font-family:var(--font-ui);font-size:13px;padding:4px 8px;border:1px solid var(--outline-variant);border-radius:var(--r-default);background:var(--surface-container-lowest);color:var(--on-surface)}.toast{position:fixed;bottom:calc(96px + env(safe-area-inset-bottom));left:50%;transform:translate(-50%);z-index:60;background:var(--inverse-surface);color:var(--inverse-on-surface);padding:10px 16px;border-radius:var(--r-pill);font-size:13px}.material-symbols-outlined{font-variation-settings:"FILL" 0,"wght" 400,"GRAD" 0,"opsz" 24}