:root{font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;--color-brand:#4555a5;--color-brand-hover:#35458f;--color-bg:#f5f7fb;--color-card:#fff;--color-border:#dce2ee;--color-border-hairline:#eef1f8;--color-text:#213547;--color-text-muted:#526076;--highlight-hover:#4555a51f;--highlight-selected:#4555a538;--highlight-guide:#4555a540;--color-shadow:#21354726;color:var(--color-text);background:var(--color-bg);font-family:system-ui,sans-serif}body{min-width:320px;min-height:100vh;margin:0}#root{min-height:100vh}main{max-width:960px;margin:0 auto;padding:48px 24px}@media (width<=480px){main{padding:48px 16px}}.intro{max-width:720px;margin-bottom:36px}.intro-top{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px 16px;display:flex}.brand{color:var(--color-brand);letter-spacing:.06em;align-items:center;gap:10px;margin:0;font-weight:700;display:flex}.logo-mark{flex-shrink:0;width:32px;height:32px}.header-controls{flex-wrap:wrap;align-items:center;gap:10px;display:flex}.lang-toggle{border:1px solid var(--color-border);background:var(--color-card);border-radius:10px;flex-shrink:0;gap:4px;padding:4px;display:inline-flex}.lang-button{color:var(--color-brand);letter-spacing:.04em;cursor:pointer;background:0 0;border:none;border-radius:8px;padding:6px 14px;font-size:.85rem;font-weight:600}.lang-button:hover{background:var(--highlight-hover)}.lang-button.is-active{background:var(--color-brand);color:var(--color-card)}.lang-button:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:2px}.header-install-button{background:var(--color-brand);color:var(--color-card);letter-spacing:.04em;cursor:pointer;border:none;border-radius:8px;flex-shrink:0;align-items:center;gap:6px;padding:11px 14px;font-size:.85rem;font-weight:600;display:inline-flex}.header-install-button svg{flex-shrink:0;width:16px;height:16px}.header-install-button:hover{background:var(--color-brand-hover)}.header-install-button:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:2px}.install-hint{max-width:100%;color:var(--color-text-muted);flex-shrink:0;align-items:flex-start;gap:6px;margin:0;font-size:.85rem;display:inline-flex}.install-hint svg{width:16px;height:16px;color:var(--color-brand);flex-shrink:0;margin-top:2px}.install-hint-text{min-width:0}.install-hint strong{color:var(--color-text);font-weight:600}h1{margin:12px 0;font-size:clamp(2rem,6vw,3rem)}p{line-height:1.7}.pronunciation-note,footer{color:var(--color-text-muted);font-size:.95rem}.lesson-zero-image{border:1px solid var(--color-border);border-radius:12px;max-width:100%;height:auto;margin-top:16px;display:block}.photo-credit{color:var(--color-text-muted);margin-top:6px;margin-bottom:0;font-size:.85rem}.install-button{background:var(--color-brand);color:var(--color-card);cursor:pointer;border:none;border-radius:8px;flex-shrink:0;padding:10px 20px;font-size:1rem;font-weight:600}.install-button:hover{background:var(--color-brand-hover)}.install-button:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:4px}.tabs{border-bottom:2px solid var(--color-border);gap:4px;max-width:720px;margin-bottom:36px;display:flex}.tab-button{color:var(--color-text-muted);cursor:pointer;background:0 0;border:none;border-bottom:3px solid #0000;margin-bottom:-2px;padding:12px 20px;font-size:1rem;font-weight:600}.tab-button:hover{color:var(--color-brand-hover);background:var(--highlight-hover)}.tab-button.is-active{color:var(--color-brand);border-bottom-color:var(--color-brand)}.tab-button:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:2px}.info-section{border:1px solid var(--color-border);background:var(--color-card);border-radius:12px;max-width:720px;margin-bottom:36px;padding:20px 24px}.info-section h2{margin-top:0}.letter-group{border:1px solid var(--color-border);border-radius:12px;max-width:720px;margin-bottom:36px;padding:20px 24px}summary{cursor:pointer;-webkit-user-select:none;user-select:none;border-radius:8px;justify-content:space-between;align-items:center;gap:12px;list-style:none;display:flex}summary::-webkit-details-marker{display:none}summary::marker{content:""}summary h2{margin:0}summary:after{content:"";border-right:2px solid var(--color-brand);border-bottom:2px solid var(--color-brand);flex-shrink:0;width:9px;height:9px;transition:transform .15s;transform:rotate(-45deg)}details[open]>summary:after{transform:rotate(45deg)}summary:hover{background:var(--highlight-hover)}summary:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:4px}.info-section summary{border-bottom:1px solid var(--color-border-hairline);margin-bottom:12px;padding-bottom:12px}.letter-group summary{border-bottom:1px solid var(--color-border-hairline);margin-bottom:16px;padding-bottom:12px}h2{font-size:1.25rem}.count{color:var(--color-text-muted);margin-left:8px;font-size:.9rem;font-weight:400}.letter-grid{grid-template-columns:repeat(auto-fit,minmax(100px,1fr));gap:12px;padding:0;list-style:none;display:grid}.letter-card{border:1px solid var(--color-border);background:var(--color-card);border-radius:12px;flex-direction:column;align-items:center;gap:8px;padding:20px 8px;display:flex}.letter{font-size:2.5rem;line-height:1.2}.sound{color:var(--color-brand)}.speak-button{border:1px solid var(--color-border);background:var(--color-bg);width:40px;height:40px;color:var(--color-brand);cursor:pointer;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;padding:0;display:inline-flex}.speak-button svg{width:18px;height:18px}.speak-button:hover{background:var(--highlight-hover)}.speak-button:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:2px}.word-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px;padding:0;list-style:none;display:grid}@media (width<=480px){.word-grid{grid-template-columns:1fr}}.word-card{border:1px solid var(--color-border);background:var(--color-card);border-radius:12px;align-items:center;gap:12px;padding:16px 18px;display:flex}.word-card-text{flex-direction:column;flex:1;gap:2px;min-width:0;display:flex}.word-hangul{font-size:1.4rem;line-height:1.3}.word-meaning{color:var(--color-text-muted);font-size:.9rem}footer{border-top:1px solid var(--color-border);padding-top:16px}.sr-only{clip:rect(0, 0, 0, 0);width:1px;height:1px;position:absolute;overflow:hidden}.table-scroll{border:1px solid var(--color-border);background:var(--color-card);border-radius:12px;overflow-x:auto}.syllable-table{border-collapse:collapse;width:100%;min-width:640px}.syllable-table th,.syllable-table td{text-align:center;border:1px solid var(--color-border-hairline)}.syllable-table th{padding:10px 8px;font-size:.95rem}.syllable-table td{padding:0}.syllable-table thead th{background:var(--color-bg);font-weight:600}.syllable-table tbody th{background:var(--color-bg);text-align:left;font-weight:600}.syllable-table thead th:first-child,.syllable-table tbody th{z-index:2;box-shadow:2px 0 4px -2px var(--color-shadow);position:sticky;left:0}.syllable-table th .sound,.syllable-table thead th span[lang=ko]{display:block}.syllable-table th .sound{margin-left:0;font-size:.75rem;font-weight:400}.syllable-cell{width:100%;font:inherit;cursor:pointer;background:0 0;border:none;padding:10px 8px;font-size:1.15rem;display:block}@media (width<=480px){.syllable-cell{padding:12px 10px}}.syllable-cell:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:-2px}.syllable-table th.is-header-hover,.syllable-table td.is-cell-hover{background:var(--highlight-hover)}.syllable-table th.is-header-selected,.syllable-table td.is-cell-selected{background:var(--highlight-selected);box-shadow:inset 0 0 0 2px var(--color-brand)}.practice-picker-label{margin:0 0 8px;font-weight:600}.practice-picker{flex-direction:column;gap:10px;margin-bottom:20px;display:flex}.practice-picker-group{flex-wrap:wrap;align-items:center;gap:8px 10px;display:flex}.practice-picker-group-label{min-width:130px;color:var(--color-text-muted);flex-shrink:0;font-size:.85rem;font-weight:600}.practice-picker-row{flex-wrap:wrap;gap:6px;display:flex}.practice-letter-chip{border:1px solid var(--color-border);background:var(--color-card);min-width:40px;color:var(--color-text);cursor:pointer;border-radius:8px;padding:6px 10px;font-size:1.1rem;line-height:1.3}.practice-letter-chip:hover{background:var(--highlight-hover)}.practice-letter-chip.is-active{border-color:var(--color-brand);background:var(--color-brand);color:var(--color-card)}.practice-letter-chip:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:2px}.practice-canvas-wrap{aspect-ratio:1;border:1px solid var(--color-border);background:var(--color-card);border-radius:12px;width:100%;max-width:280px;margin:0 auto 20px;position:relative;overflow:hidden}.practice-glyph{color:var(--color-text);opacity:.14;-webkit-user-select:none;user-select:none;pointer-events:none;justify-content:center;align-items:center;font-size:180px;line-height:1;display:flex;position:absolute;inset:0}.practice-guide{background:var(--highlight-guide);pointer-events:none;position:absolute}.practice-guide-horizontal{height:1px;top:50%;left:0;right:0}.practice-guide-vertical{width:1px;top:0;bottom:0;left:50%}.practice-canvas{touch-action:none;cursor:crosshair;width:100%;height:100%;display:block;position:relative}.practice-controls{flex-wrap:wrap;align-items:center;gap:12px 20px;display:flex}.practice-guide-toggle{color:var(--color-text-muted);cursor:pointer;align-items:center;gap:8px;font-size:.9rem;display:inline-flex}@media (width<=480px){.lang-button{padding:14px 16px}.install-button{padding:13px 20px}.header-install-button{padding:19px 16px}.tab-button{padding:14px 16px}.speak-button{width:44px;height:44px}.practice-letter-chip{padding:12px}}a{color:var(--color-brand-hover);text-underline-offset:3px}a:hover{background:var(--highlight-hover)}a:focus-visible{outline:2px solid var(--color-brand-hover);outline-offset:4px}