:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --success: #10b981;
    --danger: #ef4444;
    
    --radius-md: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.05), 0 4px 6px -2px rgba(0,0,0,0.025);
    
    --transition: all 0.2s ease-in-out;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 20px 100px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

.label {
    display: inline-block;
    padding: 4px 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background-color: #eff6ff;
    color: var(--primary);
    border-radius: 99px;
    margin-bottom: 16px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-main);
    margin-bottom: 8px;
}

header p {
    color: var(--text-muted);
    font-size: 1rem;
}

canvas { display: none; }

.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 24px;
}

.drop-zone {
    background: var(--card-bg);
    border: 2px dashed #cbd5e1;
    border-radius: var(--radius-lg);
    text-align: center;
    padding: 60px 20px;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 24px;
}

.drop-zone:hover {
    border-color: var(--primary);
    background-color: #f8fafc;
}

.drop-zone input { display: none; }

.upload-icon {
    width: 48px;
    height: 48px;
    color: var(--primary);
    margin-bottom: 16px;
}

.drop-zone h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.drop-zone span {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.controls { display: none; }
.controls.visible { display: block; animation: fadeIn 0.4s ease; }
.file-info { display: none; align-items: center; gap: 16px; }
.file-info.visible { display: flex; animation: fadeIn 0.4s ease; }
.progress-wrap, .status-box, .result-card { display: none; }
.progress-wrap.visible, .status-box.visible, .result-card.visible { display: block; animation: fadeIn 0.4s ease; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

.file-info {
    background: var(--card-bg);
    padding: 16px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    margin-bottom: 24px;
}

.file-thumb {
    width: 64px;
    height: 64px;
    object-fit: cover;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.file-name { font-size: 1rem; font-weight: 600; color: var(--text-main); }
.file-meta { font-size: 0.875rem; color: var(--text-muted); margin-top: 2px; }

.grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 24px;
}

h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 12px;
}

.input-group {
    display: flex;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
}

.input-group:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.input-group input {
    flex: 1;
    padding: 12px 16px;
    font-size: 1rem;
    border: none;
    outline: none;
    color: var(--text-main);
    background: transparent;
}

.input-group span {
    padding: 12px 16px;
    background: #f1f5f9;
    border-left: 1px solid var(--border-color);
    font-weight: 500;
    color: var(--text-muted);
}

.unit-toggle, .format-row {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    outline: none;
}

.unit-btn, .fmt-btn {
    flex: 1;
    padding: 10px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
}

.unit-btn:hover:not(.active), .fmt-btn:hover:not(.active) {
    background: #f8fafc;
    color: var(--text-main);
}

.active {
    background: #eff6ff;
    color: var(--primary);
    border-color: var(--primary);
}

.compress-btn {
    width: 100%;
    background: var(--primary);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    padding: 16px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    margin-bottom: 24px;
}

.compress-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.progress-wrap { margin-bottom: 24px; }

#progressLabel {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
    margin-bottom: 8px;
    display: block;
}

.progress-bar-bg {
    height: 8px;
    background: #f1f5f9;
    border-radius: 99px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 0;
    background: var(--primary);
    border-radius: 99px;
    transition: width 0.3s ease;
}

.status-box {
    padding: 12px 16px;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 12px;
}

.status-box svg { width: 20px; height: 20px; }

.info-box {
    background: #eff6ff;
    color: #1e3a8a;
    border: 1px solid #bfdbfe;
}

.error-box {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
    margin-bottom: 24px;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.stat-box {
    background: #f8fafc;
    padding: 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    text-align: center;
}

.stat-box.success {
    background: #ecfdf5;
    border-color: #a7f3d0;
}

.stat-box.success .stat-label { color: #047857; }
.stat-box.success strong { color: #059669; }

.stat-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-bottom: 4px;
}

.stat-box strong {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
}

.action-row {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 16px;
}

.download-btn {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 16px;
    background: var(--text-main);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.download-btn:hover {
    background: #000;
    box-shadow: var(--shadow-md);
}

.reset-btn {
    padding: 16px;
    background: white;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.reset-btn:hover {
    background: #f8fafc;
    border-color: #cbd5e1;
}

@media (max-width: 640px) {
    .grid { grid-template-columns: 1fr; gap: 16px; }
    .stats { grid-template-columns: 1fr; gap: 12px; }
    .action-row { grid-template-columns: 1fr; }
    .reset-btn { order: 2; }
    .download-btn { order: 1; }
    h1 { font-size: 2rem; }
    body { padding: 40px 16px 80px; }
}

.drop-zone.dragging { border-color: var(--primary); background-color: #eff6ff; }