/* Base Styles & CSS Variables */
:root {
    /* Light Theme Colors */
    --light-bg: #f5f5f5;
    --light-surface: #ffffff;
    --light-text: #333333;
    --light-text-secondary: #666666;
    --light-border: #e0e0e0;
    --light-accent: #4285f4; /* Google Blue */
    --light-accent-hover: #3367d6;
    --light-danger: #ea4335; /* Google Red */
    --light-success: #34a853; /* Google Green */
    --light-input-bg: #f8f8f8;
    
    /* Dark Theme Colors */
    --dark-bg: #121212;
    --dark-surface: #1e1e1e;
    --dark-text: #f5f5f5;
    --dark-text-secondary: #b0b0b0;
    --dark-border: #333333;
    --dark-accent: #4285f4;
    --dark-accent-hover: #5c9aff;
    --dark-danger: #ff6b6b;
    --dark-success: #4cd964;
    --dark-input-bg: #2a2a2a;
    
    /* Common Variables */
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

/* Apply Light Theme by Default */
body {
    --bg: var(--light-bg);
    --surface: var(--light-surface);
    --text: var(--light-text);
    --text-secondary: var(--light-text-secondary);
    --border: var(--light-border);
    --accent: var(--light-accent);
    --accent-hover: var(--light-accent-hover);
    --danger: var(--light-danger);
    --success: var(--light-success);
    --input-bg: var(--light-input-bg);
}

/* Dark Theme Class */
body.dark-theme {
    --bg: var(--dark-bg);
    --surface: var(--dark-surface);
    --text: var(--dark-text);
    --text-secondary: var(--dark-text-secondary);
    --border: var(--dark-border);
    --accent: var(--dark-accent);
    --accent-hover: var(--dark-accent-hover);
    --danger: var(--dark-danger);
    --success: var(--dark-success);
    --input-bg: var(--dark-input-bg);
}

/* Global Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background-color: var(--bg);
    color: var(--text);
    transition: var(--transition);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header Styles */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border);
}

header h1 {
    font-size: 1.8rem;
    font-weight: 600;
}

/* Theme Toggle Icon Button */
.theme-toggle {
    display: flex;
    align-items: center;
}

.theme-icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 24px;
    color: var(--text);
    position: relative;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    transition: var(--transition);
}

.theme-icon-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

body.dark-theme .theme-icon-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.light-icon, .dark-icon {
    position: absolute;
    transition: transform 0.5s ease, opacity 0.5s ease;
}

/* Light theme: show sun, hide moon */
body:not(.dark-theme) .light-icon {
    transform: translateY(0);
    opacity: 1;
}

body:not(.dark-theme) .dark-icon {
    transform: translateY(30px);
    opacity: 0;
}

/* Dark theme: show moon, hide sun */
body.dark-theme .light-icon {
    transform: translateY(-30px);
    opacity: 0;
}

body.dark-theme .dark-icon {
    transform: translateY(0);
    opacity: 1;
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Upload Container */
.upload-container {
    background-color: var(--surface);
    border: 2px dashed var(--border);
    border-radius: var(--border-radius);
    padding: 40px 20px;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    box-shadow: var(--box-shadow);
}

.upload-container:hover, .upload-container.drag-over {
    border-color: var(--accent);
    transform: translateY(-3px);
}

.upload-icon {
    margin-bottom: 15px;
}

.upload-icon .material-icons {
    font-size: 48px;
    color: var(--accent);
}

.upload-btn {
    display: inline-block;
    background-color: var(--accent);
    color: white;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    margin: 15px 0;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.upload-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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

/* Images Container */
.images-container {
    background-color: var(--surface);
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: var(--box-shadow);
    min-height: 150px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 20px;
}

.no-images-message {
    grid-column: 1 / -1;
    text-align: center;
    color: var(--text-secondary);
    padding: 30px;
    font-size: 1.1rem;
}

.image-item {
    position: relative;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    cursor: grab;
    transition: var(--transition);
    background-color: var(--bg);
    animation: fadeIn 0.3s ease;
}

.image-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.1);
}

.image-item img {
    width: 100%;
    height: 140px;
    object-fit: cover;
    display: block;
    transition: var(--transition);
}

.image-info {
    padding: 10px;
    font-size: 0.85rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    background-color: var(--surface);
}

.delete-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    background-color: var(--danger);
    color: white;
    border: none;
    border-radius: 50%;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transition: var(--transition);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

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

.delete-btn:hover {
    transform: scale(1.1);
}

.delete-btn .material-icons {
    font-size: 16px;
}

/* Actions Container */
.actions-container {
    display: flex;
    gap: 15px;
    margin-top: 20px;
    justify-content: center;
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition);
    pointer-events: none;
}

.actions-container.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: all;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

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

.primary-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

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

.secondary-btn:hover {
    background-color: var(--bg);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

/* PDF Preview */
.pdf-preview {
    background-color: var(--surface);
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--box-shadow);
    margin-top: 20px;
    display: none;
}

.pdf-preview.visible {
    display: block;
    animation: fadeIn 0.5s ease;
}

.pdf-info {
    margin-bottom: 25px;
}

.pdf-info h3 {
    color: var(--success);
    margin-bottom: 20px;
    font-size: 1.4rem;
}

.pdf-name-input-container {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
    gap: 10px;
}

.pdf-name-input-container label {
    font-weight: 500;
}

#custom-pdf-name {
    flex: 1;
    padding: 10px 15px;
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    background-color: var(--input-bg);
    color: var(--text);
    font-family: 'Poppins', sans-serif;
    transition: var(--transition);
    min-width: 200px;
}

#custom-pdf-name:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(66, 133, 244, 0.2);
}

.pdf-extension {
    font-weight: 500;
    color: var(--text-secondary);
}

.pdf-actions {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.pdf-actions .action-btn {
    flex: 1;
    min-width: 180px;
    justify-content: center;
}

/* Footer */
footer {
    margin-top: 40px;
    padding: 20px 0;
}

/* Drag and Drop Styles */
.sortable-ghost {
    opacity: 0.4;
    transform: scale(0.95);
}

.sortable-chosen {
    box-shadow: 0 0 0 2px var(--accent);
    z-index: 10;
}

.sortable-drag {
    opacity: 0.8;
    transform: rotate(2deg);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Loading Indicator */
.loading-indicator {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 20px 30px;
    background-color: var(--surface);
    color: var(--text);
    border-radius: var(--border-radius);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 12px;
    animation: fadeIn 0.3s ease;
}

.loading-indicator::after {
    content: "";
    width: 20px;
    height: 20px;
    border: 3px solid var(--accent);
    border-top: 3px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        flex-direction: row;
        align-items: center;
        padding-bottom: 20px;
    }
    
    header h1 {
        font-size: 1.5rem;
    }
    
    .images-container {
        grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
        gap: 15px;
    }
    
    .action-btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }
    
    .upload-container {
        padding: 30px 15px;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.3rem;
    }
    
    .upload-container {
        padding: 25px 15px;
    }
    
    .upload-icon .material-icons {
        font-size: 40px;
    }
    
    .images-container {
        grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
        gap: 12px;
        padding: 15px;
    }
    
    .image-item img {
        height: 120px;
    }
    
    .pdf-actions {
        flex-direction: column;
        gap: 12px;
    }
    
    .action-btn {
        width: 100%;
        justify-content: center;
        padding: 12px 16px;
    }
    
    .pdf-name-input-container {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
    
    #custom-pdf-name {
        width: 100%;
    }
}