/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #64748b;
    --secondary-hover: #475569;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 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);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

/* Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #8b5cf6 100%);
    color: white;
    padding: 2rem 1rem;
    text-align: center;
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
}

.logo-section {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
}

.header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.tagline {
    font-size: 1rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 2rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

/* Upload Section */
.upload-section {
    max-width: 600px;
    margin: 0 auto;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    background: var(--surface-color);
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.05);
}

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

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

.upload-area h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.upload-area p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.file-types {
    font-size: 0.85rem !important;
    color: var(--text-muted) !important;
    margin-top: 0.5rem;
}

.upload-area .btn {
    margin-top: 1.5rem;
}

/* File Info */
.file-info {
    margin-top: 1rem;
    background: var(--surface-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.file-details {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.file-icon {
    font-size: 1.5rem;
}

.file-meta {
    flex: 1;
    min-width: 0;
}

.file-name {
    display: block;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-size {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Processing Section */
.processing-section {
    max-width: 500px;
    margin: 0 auto;
    text-align: center;
}

.processing-content {
    background: var(--surface-color);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    box-shadow: var(--shadow-md);
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    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;
}

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

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

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), #8b5cf6);
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
}

/* Workspace Section */
.workspace-section {
    max-width: 1000px;
    margin: 0 auto;
}

.workspace-header {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.workspace-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.workspace-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

/* Export Dropdown */
.export-dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 0.5rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    min-width: 160px;
    z-index: 100;
    display: none;
}

.dropdown-menu.show {
    display: block;
}

.dropdown-item {
    width: 100%;
    padding: 0.75rem 1rem;
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--text-primary);
    transition: background 0.2s;
}

.dropdown-item:hover {
    background: var(--background-color);
}

.dropdown-item:first-child {
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.dropdown-item:last-child {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* Slides Container */
.slides-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* Slide Card */
.slide-card {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.slide-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    background: var(--background-color);
    border-bottom: 1px solid var(--border-color);
}

.slide-number {
    font-weight: 600;
    color: var(--primary-color);
}

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

.slide-body {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 1.25rem;
}

@media (min-width: 768px) {
    .slide-body {
        grid-template-columns: 300px 1fr;
    }
}

/* Slide Preview */
.slide-preview {
    background: var(--background-color);
    border-radius: var(--radius-md);
    aspect-ratio: 16/9;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.slide-preview img,
.slide-preview canvas {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.slide-preview-placeholder {
    color: var(--text-muted);
    font-size: 0.9rem;
    text-align: center;
    padding: 1rem;
}

/* Slide Notes */
.slide-notes {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.notes-label {
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.notes-textarea {
    flex: 1;
    min-height: 120px;
    padding: 0.875rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: vertical;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.notes-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.notes-textarea:disabled {
    background: var(--background-color);
    color: var(--text-muted);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--background-color);
    border-color: var(--secondary-color);
}

.btn-icon {
    width: 32px;
    height: 32px;
    padding: 0;
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.85rem;
}

.btn-full {
    width: 100%;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--surface-color);
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 480px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.125rem;
    font-weight: 600;
}

.modal-close {
    font-size: 1.25rem;
}

.modal-body {
    padding: 1.5rem;
}

.modal-body p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.25rem;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border-color);
    background: var(--background-color);
}

/* Form Elements */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

.checkbox-group label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 1rem;
    text-align: center;
}

.footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.toast {
    background: var(--surface-color);
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideIn 0.3s ease;
    max-width: 350px;
}

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

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--error-color);
}

.toast.warning {
    border-left: 4px solid var(--warning-color);
}

.toast-message {
    flex: 1;
    font-size: 0.9rem;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header {
        padding: 1.5rem 1rem;
    }

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

    .logo {
        width: 40px;
        height: 40px;
    }

    .upload-area {
        padding: 2rem 1.5rem;
    }

    .workspace-header {
        flex-direction: column;
        align-items: stretch;
    }

    .workspace-header h2 {
        text-align: center;
    }

    .workspace-actions {
        justify-content: center;
    }

    .slide-body {
        padding: 1rem;
    }

    .toast-container {
        left: 1rem;
        right: 1rem;
        bottom: 1rem;
    }

    .toast {
        max-width: none;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.25rem;
    }

    .tagline {
        font-size: 0.9rem;
    }

    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }

    .workspace-actions {
        flex-direction: column;
    }

    .workspace-actions .btn {
        width: 100%;
    }

    .export-dropdown {
        width: 100%;
    }

    .export-dropdown .btn {
        width: 100%;
    }

    .dropdown-menu {
        left: 0;
        right: 0;
    }
}

/* Dark mode support (optional, based on system preference) */
@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #0f172a;
        --surface-color: #1e293b;
        --border-color: #334155;
        --text-primary: #f1f5f9;
        --text-secondary: #94a3b8;
        --text-muted: #64748b;
    }

    .upload-area:hover,
    .upload-area.drag-over {
        background: rgba(99, 102, 241, 0.1);
    }

    .modal-overlay {
        background: rgba(0, 0, 0, 0.7);
    }
}