:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f4f4f4;
    --text-primary: #333333;
    --text-secondary: #666666;
    --accent-color: #0366d6;
    --border-color: #e1e4e8;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --hover-bg: #f8f9fa;
}

[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --accent-color: #58a6ff;
    --border-color: #404040;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --hover-bg: #333333;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s;
}

body {
    font-family: 'Inter', sans-serif;
    max-width: 1200px;
    margin: auto;
    padding: 20px;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 30px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
}

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

h2 {
    color: var(--text-primary);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 30px;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    height: 280px;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--card-shadow);
    background: var(--hover-bg);
}

.card-icon {
    font-size: 24px;
    margin-right: 10px;
    flex-shrink: 0;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    display: flex;
    align-items: flex-start;
    word-break: break-word;
    min-height: 0;
}

.card-title span:last-child {
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    font-size: 0.95rem;
    line-height: 1.4;
}

.card-preview {
    margin-top: 4px;
    border-radius: 8px;
    overflow: hidden;
    height: 180px;
    position: relative;
    flex-shrink: 0;
}

.card-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.back-button {
    background: var(--accent-color);
    color: white;
    padding: 8px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.back-button:hover {
    transform: translateX(-5px);
    opacity: 0.9;
}

.loading {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-secondary);
    text-align: center;
    padding: 40px;
}

.breadcrumb {
    margin-bottom: 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* File type badges */
.file-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
    background: var(--accent-color);
    color: white;
}

/* Preview placeholder for non-image files */
.preview-placeholder {
    height: 180px;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 3rem;
    border-radius: 8px;
    margin-top: auto;
    flex-shrink: 0;
}

/* PDF specific styles */
.pdf-preview-container {
    position: relative;
    height: 180px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    border-radius: 8px;
    overflow: hidden;
}

.pdf-preview-canvas {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.pdf-preview-actions {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 10px;
    background: rgba(0, 0, 0, 0.7);
    transition: transform 0.3s ease;
    transform: translateY(100%);
}

.card:hover .pdf-preview-actions {
    transform: translateY(0);
}

.pdf-action-button {
    padding: 6px 12px;
    border: none;
    border-radius: 4px;
    background: var(--accent-color);
    color: white;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 4px;
}

.pdf-action-button:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

/* Loading spinner */
.loading-spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 8px;
}

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

.preview-error {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 8px;
    text-align: center;
}

@media (max-width: 768px) {
    body {
        padding: 15px;
    }

    h2 {
        font-size: 2rem;
    }

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

/* Repository header and settings */
.repo-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 10px 0;
    border-bottom: 2px solid var(--border-color);
}

.repo-header h3 {
    margin: 0;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.settings-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
}

.settings-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

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

.form-group input {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(3, 102, 214, 0.2);
}

.form-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 10px;
}

.settings-button {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    background: var(--accent-color);
    color: white;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 6px;
}

.settings-button:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.settings-button.cancel {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

/* Error container */
.error-container {
    max-width: 600px;
    margin: 40px auto;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    text-align: center;
}

.error-container p {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.error-container ul {
    text-align: left;
    margin: 15px 0;
    padding-left: 20px;
    color: var(--text-secondary);
}

.error-container li {
    margin: 8px 0;
}