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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* States */
.state {
    display: none;
}

.state.active {
    display: block;
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 3rem 2rem;
    text-align: center;
    background: var(--surface);
    transition: all 0.2s ease;
    cursor: pointer;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.upload-icon {
    color: var(--text-muted);
}

.drop-text {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--text-primary);
}

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

.supported-formats {
    color: var(--text-muted);
    font-size: 0.75rem;
    margin-top: 0.5rem;
}

/* Buttons */
.button-group {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

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

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

.btn-primary:disabled {
    background: var(--text-muted);
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

.btn-large {
    padding: 0.875rem 2rem;
    font-size: 1rem;
}

.btn-link {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.875rem;
    text-decoration: underline;
    padding: 0.5rem;
}

.btn-link:hover {
    color: var(--text-primary);
}

/* Loaded State */
.loaded-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

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

.separator {
    margin: 0 0.5rem;
    color: var(--border);
}

.loaded-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.settings-bar {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--surface);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.setting {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.setting select {
    padding: 0.375rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.875rem;
    background: var(--surface);
    color: var(--text-primary);
}

/* Thumbnail Grid */
.thumbnail-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--surface);
    border-radius: 12px;
    border: 1px solid var(--border);
    max-height: 500px;
    overflow-y: auto;
}

.thumbnail-item {
    position: relative;
    aspect-ratio: 1;
    border-radius: 8px;
    overflow: hidden;
    background: var(--background);
    border: 1px solid var(--border);
}

.thumbnail-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.thumbnail-item .delete-btn {
    position: absolute;
    top: 4px;
    right: 4px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.6);
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    line-height: 1;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.thumbnail-item:hover .delete-btn {
    opacity: 1;
}

.thumbnail-item .delete-btn:hover {
    background: var(--error-color);
}

.thumbnail-item .filename {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 4px 6px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    font-size: 0.6875rem;
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

/* Processing State */
.processing-content {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--surface);
    border-radius: 12px;
    border: 1px solid var(--border);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1.5rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.processing-content h2 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

#processing-status {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.progress-bar {
    width: 100%;
    max-width: 400px;
    height: 8px;
    background: var(--border);
    border-radius: 4px;
    overflow: hidden;
    margin: 0 auto 0.5rem;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

#progress-percent {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Complete State */
.complete-content {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--surface);
    border-radius: 12px;
    border: 1px solid var(--border);
}

.success-icon {
    color: var(--success-color);
    margin-bottom: 1rem;
}

.complete-content h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

#file-size-info {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.warning {
    background: #fef3c7;
    color: #92400e;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.875rem;
}

.warning.hidden {
    display: none;
}

#download-btn {
    margin-bottom: 1rem;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 1000;
}

.toast {
    padding: 0.875rem 1.25rem;
    background: var(--text-primary);
    color: white;
    border-radius: 8px;
    font-size: 0.875rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    animation: slideIn 0.3s ease;
}

.toast.warning {
    background: var(--warning-color);
    color: #1e293b;
}

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

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Responsive */
@media (max-width: 640px) {
    .container {
        padding: 1rem;
    }

    .loaded-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .thumbnail-grid {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    }

    .settings-bar {
        flex-direction: column;
        gap: 0.75rem;
    }
}