:root{--color-bg:#f8f8f6;--color-surface:#fff;--color-surface-alt:#f2f2ef;--color-border:#e4e4e0;--color-border-hover:#c8c8c2;--color-ink:#1a1a18;--color-ink-secondary:#5a5a54;--color-ink-muted:#9a9a92;--color-accent:#2563eb;--color-accent-hover:#1d4ed8;--color-accent-light:#dbeafe;--color-accent-text:#1e40af;--color-success:#16a34a;--color-success-light:#dcfce7;--color-error:#dc2626;--color-error-light:#fee2e2;--color-warning:#d97706;--color-warning-light:#fef3c7;--font-sans:"Inter",system-ui,-apple-system,sans-serif;--radius-sm:6px;--radius-md:10px;--radius-lg:16px;--radius-xl:24px;--shadow-sm:0 1px 3px rgba(0,0,0,.06),0 1px 2px rgba(0,0,0,.04);--shadow-md:0 4px 12px rgba(0,0,0,.08),0 2px 4px rgba(0,0,0,.04);--shadow-lg:0 12px 32px rgba(0,0,0,.1),0 4px 8px rgba(0,0,0,.04);--transition:150ms ease;--transition-slow:300ms ease}[data-theme=dark]{--color-bg:#111110;--color-surface:#1c1c1a;--color-surface-alt:#242422;--color-border:#2e2e2c;--color-border-hover:#444442;--color-ink:#f0f0ee;--color-ink-secondary:#a8a8a2;--color-ink-muted:#666660;--color-accent:#3b82f6;--color-accent-hover:#60a5fa;--color-accent-light:#1e3a5f;--color-accent-text:#93c5fd;--color-success:#22c55e;--color-success-light:#14532d;--color-error:#f87171;--color-error-light:#7f1d1d}*,:after,:before{box-sizing:border-box}html{font-size:16px;-webkit-font-smoothing:antialiased;scroll-behavior:smooth}body{padding:0;font-family:var(--font-sans);background:var(--color-bg);line-height:1.6;min-height:100vh;transition:background var(--transition-slow),color var(--transition-slow)}body,h1,h2,h3,h4{margin:0;color:var(--color-ink)}h1,h2,h3,h4{line-height:1.25;letter-spacing:-.02em}h1{font-size:clamp(1.75rem,4vw,2.5rem);font-weight:700}h2{font-size:clamp(1.375rem,3vw,1.875rem);font-weight:650}h3{font-size:1.25rem;font-weight:600}p{margin:0}a{color:var(--color-accent);text-decoration:none;transition:color var(--transition)}a:hover{color:var(--color-accent-hover);text-decoration:underline}a:focus-visible{outline:2px solid var(--color-accent);outline-offset:2px;border-radius:2px}.container{width:100%;max-width:1080px;margin:0 auto;padding:0 20px}@media (min-width:640px){.container{padding:0 32px}}.site-header{position:-webkit-sticky;position:sticky;top:0;z-index:100;background:hsla(60,12%,97%,.88);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);border-bottom:1px solid var(--color-border);transition:background var(--transition-slow)}[data-theme=dark] .site-header{background:rgba(17,17,16,.88)}.site-header-inner{display:flex;align-items:center;justify-content:space-between;height:60px;gap:16px}.site-logo{font-size:1.125rem;font-weight:700;color:var(--color-ink);text-decoration:none;letter-spacing:-.03em}.site-logo:hover{color:var(--color-accent);text-decoration:none}.site-nav{display:flex;align-items:center;gap:4px}.site-nav a{font-size:.875rem;font-weight:500;color:var(--color-ink-secondary);padding:6px 12px;border-radius:var(--radius-sm);transition:background var(--transition),color var(--transition)}.site-nav a:hover{color:var(--color-ink);text-decoration:none}.site-nav a:hover,.theme-toggle{background:var(--color-surface-alt)}.theme-toggle{width:36px;height:36px;border-radius:var(--radius-sm);border:1px solid var(--color-border);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:1rem;transition:all var(--transition);color:var(--color-ink-secondary)}.theme-toggle:hover{background:var(--color-border);color:var(--color-ink)}.hero{padding:64px 0 48px;text-align:center}.hero-eyebrow{display:inline-flex;align-items:center;gap:6px;font-size:.8125rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--color-accent);background:var(--color-accent-light);padding:4px 12px;border-radius:100px;margin-bottom:20px}.hero h1{margin-bottom:16px}.hero-sub{font-size:1.125rem;color:var(--color-ink-secondary);max-width:560px;margin:0 auto 40px}.category-tabs{display:flex;gap:4px;padding:4px;background:var(--color-surface-alt);border-radius:var(--radius-lg);border:1px solid var(--color-border);overflow-x:auto;-webkit-overflow-scrolling:touch}.category-tab{flex:1 1;min-width:-moz-fit-content;min-width:fit-content;padding:10px 20px;font-size:.9375rem;font-weight:600;border-radius:var(--radius-md);border:none;cursor:pointer;transition:all var(--transition);font-family:var(--font-sans);color:var(--color-ink-secondary);background:transparent;white-space:nowrap;display:flex;align-items:center;justify-content:center;gap:6px}.category-tab.active,.category-tab:hover{color:var(--color-ink);background:var(--color-surface)}.card,.category-tab.active{box-shadow:var(--shadow-sm)}.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:24px}.card-lg{padding:32px}@media (max-width:640px){.card-lg{padding:20px}}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 20px;font-size:.9375rem;font-weight:600;border-radius:var(--radius-md);border:none;cursor:pointer;transition:all var(--transition);text-decoration:none;white-space:nowrap;font-family:var(--font-sans)}.btn:focus-visible{outline:2px solid var(--color-accent);outline-offset:2px}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:var(--color-accent);color:#fff}.btn-primary:hover:not(:disabled){background:var(--color-accent-hover);transform:translateY(-1px);box-shadow:var(--shadow-md);color:#fff;text-decoration:none}.btn-secondary{background:var(--color-surface-alt);color:var(--color-ink);border:1px solid var(--color-border)}.btn-secondary:hover:not(:disabled){background:var(--color-border);text-decoration:none;color:var(--color-ink)}.btn-lg{padding:14px 28px;font-size:1rem}.btn-full{width:100%}.form-label{display:block;font-size:.875rem;font-weight:500;color:var(--color-ink-secondary);margin-bottom:6px}.form-input,.form-select{width:100%;padding:10px 14px;font-size:.9375rem;font-family:var(--font-sans);border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-surface);color:var(--color-ink);transition:border-color var(--transition),box-shadow var(--transition);-webkit-appearance:none;-moz-appearance:none;appearance:none;outline:none}.form-input:focus,.form-select:focus{border-color:var(--color-accent);box-shadow:0 0 0 3px var(--color-accent-light)}.dropzone{border:2px dashed var(--color-border);border-radius:var(--radius-lg);padding:48px 24px;text-align:center;cursor:pointer;transition:all var(--transition-slow);background:var(--color-surface)}.dropzone.drag-over,.dropzone:hover{border-color:var(--color-accent);background:var(--color-accent-light)}.dropzone-icon{width:48px;height:48px;margin:0 auto 16px;color:var(--color-ink-muted)}.dropzone.drag-over .dropzone-icon{color:var(--color-accent)}.dropzone-title{font-size:1rem;font-weight:600;color:var(--color-ink);margin-bottom:6px}.dropzone-hint{font-size:.875rem;color:var(--color-ink-muted)}@media (max-width:480px){.dropzone{padding:32px 16px}}.progress-bar-wrap{height:6px;background:var(--color-surface-alt);border-radius:100px;overflow:hidden}.progress-bar{height:100%;background:var(--color-accent);border-radius:100px;transition:width .3s ease}.file-item{display:flex;align-items:center;gap:12px;padding:12px 16px;border-radius:var(--radius-md);border:1px solid var(--color-border);background:var(--color-surface);transition:border-color var(--transition);animation:slideIn .2s ease}@keyframes slideIn{0%{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}.file-item+.file-item{margin-top:8px}.file-item-info{flex:1 1;min-width:0}.file-item-name{font-size:.9375rem;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.file-item-meta{font-size:.8125rem;color:var(--color-ink-muted)}.file-item-status{font-size:.8125rem;font-weight:600;padding:3px 10px;border-radius:100px;flex-shrink:0}.status-waiting{background:var(--color-surface-alt);color:var(--color-ink-secondary)}.status-processing{background:var(--color-accent-light);color:var(--color-accent-text)}.status-completed{background:var(--color-success-light);color:var(--color-success)}.status-failed{background:var(--color-error-light);color:var(--color-error)}.converter-options{display:grid;grid-template-columns:1fr 1fr;grid-gap:16px;gap:16px;margin:20px 0}@media (max-width:480px){.converter-options{grid-template-columns:1fr}}.preset-btn{padding:6px 14px;font-size:.8125rem;font-weight:600;border-radius:100px;border:1.5px solid var(--color-border);background:var(--color-surface);cursor:pointer;transition:all var(--transition);font-family:var(--font-sans);color:var(--color-ink-secondary)}.preset-btn.active,.preset-btn:hover{border-color:var(--color-accent);color:var(--color-accent);background:var(--color-accent-light)}.converter-presets{display:flex;gap:8px;flex-wrap:wrap;margin-top:8px}.faq-item{border-bottom:1px solid var(--color-border)}.faq-question{width:100%;display:flex;justify-content:space-between;align-items:center;padding:18px 0;font-size:1rem;font-weight:600;cursor:pointer;background:none;border:none;font-family:var(--font-sans);color:var(--color-ink);text-align:left;transition:color var(--transition)}.faq-question:hover{color:var(--color-accent)}.faq-icon{flex-shrink:0;width:20px;height:20px;transition:transform var(--transition)}.faq-item.open .faq-icon{transform:rotate(45deg)}.faq-answer{font-size:.9375rem;color:var(--color-ink-secondary);line-height:1.7;padding-bottom:18px;display:none}.faq-item.open .faq-answer{display:block}.category-grid{display:grid;grid-template-columns:repeat(2,1fr);grid-gap:16px;gap:16px;margin-top:32px}@media (min-width:768px){.category-grid{grid-template-columns:repeat(4,1fr)}}@media (max-width:520px){.category-grid{grid-template-columns:1fr 1fr}}.category-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:24px 20px;text-decoration:none;display:block;transition:all var(--transition-slow)}.category-card:hover{border-color:var(--color-accent);box-shadow:var(--shadow-md);transform:translateY(-2px);text-decoration:none}.category-icon{font-size:2rem;margin-bottom:12px}.category-title{font-size:1.0625rem;font-weight:700;color:var(--color-ink);margin-bottom:6px}.category-desc{font-size:.8125rem;color:var(--color-ink-secondary)}.section{padding:48px 0}.section+.section{border-top:1px solid var(--color-border)}.section-title{margin-bottom:24px}.steps{flex-direction:column}.step,.steps{display:flex;gap:16px}.step{align-items:flex-start}.step-number{width:32px;height:32px;border-radius:50%;background:var(--color-accent);color:#fff;font-weight:700;font-size:.875rem;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:2px}.step-content h4{font-size:.9375rem;margin-bottom:4px}.step-content p{font-size:.875rem;color:var(--color-ink-secondary)}.related-links{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}.related-link{font-size:.875rem;font-weight:500;padding:6px 14px;background:var(--color-surface-alt);border:1px solid var(--color-border);border-radius:100px;color:var(--color-ink-secondary);transition:all var(--transition)}.related-link:hover{border-color:var(--color-accent);color:var(--color-accent);text-decoration:none;background:var(--color-accent-light)}.compare-table{width:100%;border-collapse:collapse;font-size:.9375rem}.compare-table th{padding:10px 16px;text-align:left;font-size:.8125rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-ink-muted);border-bottom:2px solid var(--color-border)}.compare-table td{padding:12px 16px;border-bottom:1px solid var(--color-border);color:var(--color-ink-secondary)}.compare-table td:first-child{color:var(--color-ink);font-weight:500}.site-footer{border-top:1px solid var(--color-border);padding:32px 0;margin-top:48px}.site-footer-inner{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;font-size:.875rem;color:var(--color-ink-muted)}@media (max-width:640px){.site-footer-inner{flex-direction:column;text-align:center}}.alert{padding:12px 16px;border-radius:var(--radius-md);font-size:.9375rem;display:flex;align-items:flex-start;gap:10px}.alert-error{background:var(--color-error-light);color:var(--color-error);border:1px solid #fca5a5}.alert-success{background:var(--color-success-light);color:var(--color-success);border:1px solid #86efac}@media (max-width:640px){.hero{padding:40px 0 32px}.category-tabs{gap:2px}.category-tab{padding:8px 14px;font-size:.875rem}}@media (prefers-reduced-motion:reduce){*,:after,:before{transition-duration:.01ms!important;animation-duration:.01ms!important}}.doc-viewer-overlay{position:fixed;inset:0;z-index:1000;background:rgba(0,0,0,.75);display:flex;flex-direction:column;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);animation:fadeIn .15s ease}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}.doc-viewer-toolbar{display:flex;align-items:center;justify-content:space-between;padding:12px 20px;background:var(--color-surface);border-bottom:1px solid var(--color-border);flex-shrink:0;gap:12px}.doc-viewer-title{font-weight:600;font-size:.9375rem;color:var(--color-ink);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1 1;min-width:0}.doc-viewer-body{flex:1 1;position:relative;overflow:hidden;background:#525659}.doc-viewer-loading{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:var(--color-surface);z-index:1;flex-direction:column;gap:12px;color:var(--color-ink-secondary)}.av-badge{display:inline-flex;align-items:center;gap:6px;font-size:.8125rem;font-weight:500;color:var(--color-success);background:var(--color-success-light);padding:4px 12px;border-radius:100px;margin-top:12px}