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

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --success-color: #10b981;
    --success-hover: #059669;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --background: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo svg {
    color: var(--primary-color);
}

.logo h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

main {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

section {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
}

section h2 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 1rem;
    padding: 3rem 2rem;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, #eef2ff 0%, #e0e7ff 100%);
}

.upload-area.dragover {
    transform: scale(1.02);
}

.upload-icon {
    margin-bottom: 1rem;
}

.upload-icon svg {
    color: var(--primary-color);
    opacity: 0.8;
}

.upload-area h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.file-types {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

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

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: var(--secondary-hover);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.setting-item label {
    font-weight: 500;
    color: var(--text-primary);
}

.setting-item input[type="number"],
.setting-item select {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s ease;
}

.setting-item input[type="number"]:focus,
.setting-item select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.range-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.range-container input[type="range"] {
    flex: 1;
    height: 8px;
    border-radius: 4px;
    background: var(--border-color);
    -webkit-appearance: none;
    appearance: none;
}

.range-container input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    transition: transform 0.2s ease;
}

.range-container input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.range-value {
    min-width: 50px;
    font-weight: 600;
    color: var(--primary-color);
}

.setting-hint {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.action-buttons {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
}

.preview-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.image-card {
    background: var(--background);
    border-radius: 0.75rem;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.image-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.image-preview {
    position: relative;
    aspect-ratio: 16/10;
    overflow: hidden;
    background: #f1f5f9;
}

.image-preview img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.image-badge {
    position: absolute;
    top: 0.5rem;
    left: 0.5rem;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: white;
}

.badge-original {
    background: var(--secondary-color);
}

.badge-compressed {
    background: var(--success-color);
}

.image-info {
    padding: 1rem;
}

.image-name {
    font-weight: 500;
    margin-bottom: 0.5rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.image-stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.savings {
    color: var(--success-color);
    font-weight: 600;
}

.savings.negative {
    color: #ef4444;
}

.image-actions {
    display: flex;
    gap: 0.5rem;
}

.image-actions .btn {
    flex: 1;
}

.download-all-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.total-saved {
    font-size: 1rem;
    color: var(--success-color);
    font-weight: 600;
}

.progress-section {
    text-align: center;
}

.progress-bar {
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), #a855f7);
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    color: var(--text-secondary);
}

footer {
    margin-top: 3rem;
    text-align: center;
}

.features {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.feature svg {
    color: var(--primary-color);
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    section {
        padding: 1.5rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .preview-container {
        grid-template-columns: 1fr;
    }

    .features {
        flex-direction: column;
        gap: 1rem;
    }

    .download-all-container {
        flex-direction: column;
    }
}

/* 加载动画 */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 2s infinite;
}

/* 成功提示 */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--text-primary);
    color: white;
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(1rem);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.toast.success {
    background: var(--success-color);
}

.toast.error {
    background: #ef4444;
}