*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f0f2f5; --surface: #fff; --primary: #6366f1; --primary-hover: #4f46e5;
  --primary-light: #eef2ff; --primary-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
  --text: #0f172a; --text-secondary: #64748b; --text-tertiary: #94a3b8;
  --border: #e2e8f0; --radius: 12px; --radius-sm: 8px; --radius-lg: 16px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -1px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 40px -5px rgba(0,0,0,0.1);
  --success: #22c55e; --success-bg: #f0fdf4;
  --warning: #f59e0b; --warning-bg: #fffbeb;
  --danger: #ef4444; --danger-bg: #fef2f2;
  --info: #3b82f6; --info-bg: #eff6ff;
}
body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

.header { background: rgba(255,255,255,0.9); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.header .container { display: flex; align-items: center; height: 64px; gap: 32px; }
.logo { font-size: 1.35rem; font-weight: 800; background: var(--primary-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; text-decoration: none; white-space: nowrap; letter-spacing: -0.5px; }
.nav { display: flex; gap: 2px; overflow-x: auto; flex: 1; scrollbar-width: none; align-items: center; }
.nav::-webkit-scrollbar { display: none; }
.nav-link { text-decoration: none; color: var(--text-secondary); font-size: 0.82rem; font-weight: 500; padding: 6px 14px; border-radius: 8px; white-space: nowrap; transition: all 0.15s; }
.nav-link:hover { background: var(--primary-light); color: var(--primary); }
.nav-link.current-page { background: var(--primary); color: #fff; }
.menu-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--text); padding: 4px; }

.main-content { padding: 40px 0 80px; }

.hero { text-align: center; padding: 60px 0 48px; position: relative; }
.hero::after { content: ''; position: absolute; top: -50%; left: 50%; transform: translateX(-50%); width: 600px; height: 600px; background: radial-gradient(circle, rgba(99,102,241,0.06) 0%, transparent 70%); pointer-events: none; }
.hero h1 { font-size: 2.8rem; font-weight: 800; letter-spacing: -1px; line-height: 1.15; margin-bottom: 16px; }
.hero h1 span { background: var(--primary-gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { font-size: 1.1rem; color: var(--text-secondary); max-width: 560px; margin: 0 auto 32px; line-height: 1.7; }
.hero-search { display: flex; max-width: 480px; margin: 0 auto; }
.hero-search input { flex: 1; padding: 14px 20px; border: 2px solid var(--border); border-radius: 12px 0 0 12px; font-size: 0.95rem; outline: none; transition: border-color 0.15s; }
.hero-search input:focus { border-color: var(--primary); }
.hero-search button { padding: 14px 28px; background: var(--primary); color: #fff; border: none; border-radius: 0 12px 12px 0; font-size: 0.95rem; font-weight: 600; cursor: pointer; transition: background 0.15s; }
.hero-search button:hover { background: var(--primary-hover); }

.home-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }
.home-card { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px; text-decoration: none; color: var(--text); transition: all 0.2s; display: flex; flex-direction: column; gap: 8px; border: 1px solid var(--border); position: relative; overflow: hidden; }
.home-card::before { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--primary-gradient); opacity: 0; transition: opacity 0.2s; }
.home-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary); }
.home-card:hover::before { opacity: 1; }
.home-card .icon { font-size: 2rem; margin-bottom: 4px; }
.home-card .tag { font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; color: var(--primary); }
.home-card h3 { font-size: 1.05rem; font-weight: 700; }
.home-card p { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.5; }

.category-section { margin-bottom: 40px; }
.category-header { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; padding-bottom: 12px; border-bottom: 2px solid var(--border); }
.category-header .cat-icon { font-size: 1.5rem; }
.category-header h2 { font-size: 1.25rem; font-weight: 700; color: var(--text); }

.tool-card { background: var(--surface); border-radius: var(--radius-lg); box-shadow: var(--shadow-md); padding: 32px; border: 1px solid var(--border); }

.breadcrumb { padding: 12px 0 4px; font-size: 0.82rem; color: var(--text-tertiary); display: flex; align-items: center; gap: 8px; }
.breadcrumb a { color: var(--primary); text-decoration: none; font-weight: 500; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb .sep { color: var(--text-tertiary); }
.breadcrumb .current { font-weight: 600; color: var(--text); }

.page-header { margin-bottom: 24px; }
.page-header .tool-icon { font-size: 2.4rem; margin-bottom: 8px; }
.page-header h1 { font-size: 2rem; font-weight: 800; margin-bottom: 8px; line-height: 1.2; letter-spacing: -0.5px; }
.page-header p { color: var(--text-secondary); font-size: 0.95rem; max-width: 700px; line-height: 1.7; }

.steps { display: flex; gap: 8px; margin-bottom: 24px; flex-wrap: wrap; }
.step { display: flex; align-items: center; gap: 8px; padding: 8px 16px; background: var(--bg); border-radius: 100px; font-size: 0.8rem; font-weight: 500; color: var(--text-secondary); }
.step .num { width: 22px; height: 22px; border-radius: 50%; background: var(--primary); color: #fff; display: flex; align-items: center; justify-content: center; font-size: 0.72rem; font-weight: 700; flex-shrink: 0; }
.step.active { background: var(--primary-light); color: var(--primary); }

.dropzone { border: 2px dashed var(--border); border-radius: var(--radius-lg); padding: 48px 32px; text-align: center; cursor: pointer; transition: all 0.2s; background: var(--surface); }
.dropzone:hover, .dropzone.dragover { border-color: var(--primary); background: var(--primary-light); }
.dropzone:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(99,102,241,0.15); }
.dropzone.has-files { padding: 32px 24px; }
.dropzone .drop-icon { font-size: 3rem; margin-bottom: 12px; }
.dropzone .drop-title { font-weight: 700; font-size: 1.05rem; margin-bottom: 4px; }
.dropzone .drop-hint { color: var(--text-tertiary); font-size: 0.82rem; }
.dropzone .drop-formats { margin-top: 12px; display: flex; gap: 6px; justify-content: center; flex-wrap: wrap; }
.dropzone .drop-formats span { padding: 3px 10px; background: var(--primary-light); color: var(--primary); border-radius: 100px; font-size: 0.72rem; font-weight: 600; }

.file-list { margin-top: 16px; }
.file-item { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--bg); border-radius: var(--radius-sm); margin-bottom: 8px; border: 1px solid var(--border); }
.file-item .file-icon { font-size: 1.3rem; }
.file-item .name { flex: 1; font-size: 0.9rem; font-weight: 500; }
.file-item .size { color: var(--text-secondary); font-size: 0.8rem; }
.file-item .remove { background: none; border: none; color: var(--danger); cursor: pointer; font-size: 1.2rem; padding: 2px 8px; border-radius: 4px; transition: background 0.15s; }
.file-item .remove:hover { background: var(--danger-bg); }

.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; border: none; border-radius: var(--radius-sm); font-size: 0.92rem; font-weight: 600; cursor: pointer; transition: all 0.15s; outline: none; }
.btn:focus-visible { box-shadow: 0 0 0 3px rgba(99,102,241,0.4); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }
.btn-secondary { background: var(--bg); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover { background: var(--border); }
.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { opacity: 0.9; transform: translateY(-1px); }
.btn-sm { padding: 8px 16px; font-size: 0.82rem; }
.btn-icon { width: 40px; height: 40px; padding: 0; border-radius: var(--radius-sm); }

.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 6px; font-size: 0.88rem; color: var(--text); }
.form-group input, .form-group select, .form-group textarea { width: 100%; padding: 12px 16px; border: 1.5px solid var(--border); border-radius: var(--radius-sm); font-size: 0.92rem; transition: border-color 0.15s, box-shadow 0.15s; background: var(--surface); }
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(99,102,241,0.1); }

.slider-group { display: flex; align-items: center; gap: 12px; }
.slider-group input[type="range"] { flex: 1; height: 6px; -webkit-appearance: none; appearance: none; background: var(--border); border-radius: 3px; outline: none; }
.slider-group input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 20px; height: 20px; border-radius: 50%; background: var(--primary); cursor: pointer; border: 3px solid #fff; box-shadow: var(--shadow-md); }

.flex-row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.flex-between { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }

.size-badge { background: var(--bg); padding: 6px 14px; border-radius: 100px; font-size: 0.8rem; font-weight: 600; border: 1px solid var(--border); }
.size-badge.success { background: var(--success-bg); color: #166534; border-color: #bbf7d0; }

.preview-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 16px; }
.preview-box { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--surface); }
.preview-box img, .preview-box canvas { width: 100%; display: block; }
.preview-box .label { padding: 10px 16px; font-size: 0.78rem; font-weight: 600; background: var(--bg); border-bottom: 1px solid var(--border); text-transform: uppercase; letter-spacing: 0.3px; color: var(--text-secondary); }

.page-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 12px; margin-top: 16px; }
.page-thumb { border: 2px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; cursor: pointer; transition: all 0.15s; position: relative; }
.page-thumb.selected { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99,102,241,0.2); }
.page-thumb canvas, .page-thumb img { width: 100%; display: block; }
.page-thumb .page-num { position: absolute; bottom: 0; left: 0; right: 0; background: rgba(0,0,0,0.6); color: #fff; text-align: center; font-size: 0.72rem; padding: 3px; backdrop-filter: blur(4px); }

.result-box { margin-top: 24px; padding: 24px; background: var(--bg); border-radius: var(--radius); border: 1px solid var(--border); }
.result-box h3 { margin-bottom: 12px; font-size: 1.05rem; }

.table-wrap { overflow-x: auto; margin-top: 16px; border: 1px solid var(--border); border-radius: var(--radius-sm); }
table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
th, td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
th { font-weight: 600; background: var(--bg); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.3px; color: var(--text-secondary); }
tr:last-child td { border-bottom: none; }

.chart-wrap { max-width: 360px; margin: 24px auto; }

.badge { display: inline-block; padding: 4px 14px; border-radius: 100px; font-size: 0.78rem; font-weight: 600; }
.badge-success { background: var(--success-bg); color: #166534; }
.badge-warning { background: var(--warning-bg); color: #92400e; }
.badge-danger { background: var(--danger-bg); color: #991b1b; }
.badge-info { background: var(--info-bg); color: #1e40af; }

.stats-bar { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 12px; margin-bottom: 20px; }
.stat-item { background: var(--bg); padding: 20px; border-radius: var(--radius); text-align: center; border: 1px solid var(--border); }
.stat-item .value { font-size: 1.8rem; font-weight: 800; letter-spacing: -0.5px; }
.stat-item .label { font-size: 0.72rem; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.5px; margin-top: 2px; }

.progress-bar { height: 6px; background: var(--border); border-radius: 999px; overflow: hidden; margin-top: 8px; }
.progress-bar .fill { height: 100%; background: var(--primary); border-radius: 999px; transition: width 0.3s ease; }
.progress-bar .fill.warning { background: var(--warning); }
.progress-bar .fill.danger { background: var(--danger); }

.seo-content { margin-top: 56px; padding-top: 40px; border-top: 1px solid var(--border); }
.seo-content h2 { font-size: 1.35rem; font-weight: 700; margin-bottom: 16px; margin-top: 36px; letter-spacing: -0.3px; }
.seo-content h2:first-child { margin-top: 0; }
.seo-content h3 { font-size: 1.05rem; font-weight: 600; margin-bottom: 8px; margin-top: 20px; }
.seo-content p, .seo-content li { color: var(--text-secondary); line-height: 1.8; }
.seo-content ol, .seo-content ul { padding-left: 24px; margin-bottom: 16px; }
.seo-content li { margin-bottom: 8px; }

.related-tools { margin-top: 56px; padding-top: 40px; border-top: 1px solid var(--border); }
.related-tools h2 { font-size: 1.35rem; font-weight: 700; margin-bottom: 20px; }

.toast { position: fixed; bottom: 24px; right: 24px; background: var(--text); color: #fff; padding: 14px 24px; border-radius: var(--radius-sm); font-size: 0.88rem; font-weight: 500; opacity: 0; transform: translateY(20px) scale(0.95); transition: all 0.25s cubic-bezier(0.22, 1, 0.36, 1); z-index: 200; box-shadow: var(--shadow-xl); }
.toast.show { opacity: 1; transform: translateY(0) scale(1); }
.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }
.toast.info { background: var(--info); }

/* Loading States */
.btn.loading { position: relative; pointer-events: none; }
.btn.loading::after { content: ''; position: absolute; width: 16px; height: 16px; border: 2px solid transparent; border-top-color: #fff; border-radius: 50%; animation: spin 0.8s linear infinite; }
.btn.loading.btn-secondary::after { border-top-color: var(--text); }
@keyframes spin { to { transform: rotate(360deg); } }

.spinner { width: 32px; height: 32px; border: 3px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin 0.8s linear infinite; margin: 20px auto; }
.spinner-lg { width: 48px; height: 48px; border-width: 4px; }

/* Empty State */
.empty-state { text-align: center; padding: 48px 24px; color: var(--text-secondary); }
.empty-state .empty-icon { font-size: 3rem; margin-bottom: 12px; opacity: 0.5; }
.empty-state .empty-title { font-size: 1.1rem; font-weight: 600; color: var(--text); margin-bottom: 4px; }
.empty-state .empty-hint { font-size: 0.85rem; }

/* Loading Overlay */
.loading-overlay { position: absolute; inset: 0; background: rgba(255,255,255,0.9); display: flex; align-items: center; justify-content: center; flex-direction: column; gap: 16px; border-radius: inherit; z-index: 10; }
.loading-overlay .spinner-text { font-weight: 600; color: var(--text); }

/* File Item States */
.file-item.processing { animation: pulse-bg 1.5s infinite; }
@keyframes pulse-bg { 0%, 100% { background: var(--bg); } 50% { background: var(--primary-light); } }
.file-item.done { border-color: var(--success); background: var(--success-bg); }

/* Better Dropzone Focus */
.dropzone.focused { border-color: var(--primary); background: var(--primary-light); transform: scale(1.01); }

/* Progress Ring */
.progress-ring { width: 48px; height: 48px; }
.progress-ring circle { fill: none; stroke-width: 4; }
.progress-ring .bg { stroke: var(--border); }
.progress-ring .progress { stroke: var(--primary); stroke-linecap: round; transform: rotate(-90deg); transform-origin: 50% 50%; transition: stroke-dashoffset 0.3s; }

/* Step Completed */
.step.completed { background: var(--success-bg); color: #166534; }
.step.completed .num { background: var(--success); }
.step.completed::after { content: '✓'; position: absolute; right: 6px; font-size: 0.6rem; }

/* Card Hover Enhancement */
.home-card { cursor: pointer; }
.home-card:active { transform: scale(0.98); }

/* Result Animation */
.result-box { animation: slideUp 0.35s ease; }

/* Form Focus Enhancement */
.form-group input:focus, .form-group select:focus, .form-group textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(99,102,241,0.1), 0 2px 8px rgba(99,102,241,0.1); }

/* Better Select */
.form-group select { cursor: pointer; appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2364748b' d='M6 8L1 3h10z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 12px center; padding-right: 36px; }

/* Toggle Buttons Group */
.toggle-group { display: flex; background: var(--bg); border-radius: var(--radius-sm); padding: 4px; gap: 4px; }
.toggle-group .toggle-btn { flex: 1; padding: 10px 16px; border: none; background: transparent; border-radius: var(--radius-sm); font-size: 0.85rem; font-weight: 500; cursor: pointer; transition: all 0.15s; color: var(--text-secondary); }
.toggle-group .toggle-btn:hover { color: var(--text); }
.toggle-group .toggle-btn.active { background: var(--surface); color: var(--primary); box-shadow: var(--shadow); }

/* Result Card Better Design */
.result-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; margin-top: 12px; display: flex; align-items: center; gap: 12px; }
.result-card .result-icon { width: 40px; height: 40px; background: var(--primary-light); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-size: 1.2rem; }
.result-card .result-info { flex: 1; }
.result-card .result-name { font-weight: 600; font-size: 0.9rem; }
.result-card .result-size { font-size: 0.78rem; color: var(--text-secondary); }
.result-card .result-action { padding: 8px 16px; }

.footer { background: var(--surface); border-top: 1px solid var(--border); padding: 32px 0; text-align: center; }
.footer p { color: var(--text-tertiary); font-size: 0.82rem; }

@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
@keyframes fadeIn { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.fade-in { animation: fadeIn 0.3s ease; }
.slide-up { animation: slideUp 0.35s ease; }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 16px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }

@media (max-width: 768px) {
  .header .container { gap: 16px; }
  .nav { display: none; position: absolute; top: 64px; left: 0; right: 0; background: rgba(255,255,255,0.98); backdrop-filter: blur(12px); flex-direction: column; padding: 12px; box-shadow: var(--shadow-xl); border-bottom: 1px solid var(--border); max-height: 60vh; overflow-y: auto; }
  .nav.open { display: flex; }
  .menu-toggle { display: block; }
  .hero h1 { font-size: 1.8rem; }
  .hero p { font-size: 1rem; }
  .hero { padding: 40px 0 32px; }
  .preview-grid { grid-template-columns: 1fr; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .home-grid { grid-template-columns: 1fr; }
  .tool-card { padding: 20px; }
  .page-header h1 { font-size: 1.5rem; }
  .steps { gap: 6px; }
  .step { font-size: 0.72rem; padding: 6px 12px; }
  .step .num { width: 18px; height: 18px; font-size: 0.65rem; }
  .stat-item .value { font-size: 1.4rem; }
  .dropzone { padding: 32px 20px; }
}