/* Variables */
:root {
    --color-primary: #286c44;
    --color-primary-hover: #1f5434;

    /* Typography - System sans-serif font */
    --font-body: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --color-bg: #ffffff;
    --color-bg-secondary: #ffffff;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-border: #e2e8f0;

    /* Diff colors */
    --color-add-bg: #dcfce7;
    --color-add-text: #166534;
    --color-add-border: #86efac;
    --color-del-bg: #fee2e2;
    --color-del-text: #991b1b;
    --color-del-border: #fca5a5;
    --color-unchanged-bg: #ffffff;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
}

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

/* Base */
html {
    font-size: 14px;
}

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background-color: var(--color-bg-secondary);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    background: var(--color-bg);
    padding: var(--spacing-xs) var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    border-bottom: 1px solid var(--color-border);
}

header h1 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin: 0;
    white-space: nowrap;
}

.subtitle {
    color: var(--color-text-secondary);
    font-size: 0.8rem;
    margin: 0;
}

.subtitle a {
    color: var(--color-primary);
    text-decoration: none;
}

.subtitle a:hover {
    text-decoration: underline;
}

/* Main */
main {
    flex: 1;
    padding: var(--spacing-xs) var(--spacing-lg);
    max-width: 1600px;
    margin: 0 auto;
    width: 100%;
}

/* Controls */
.controls {
    background: var(--color-bg);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xs);
}

.controls-row {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    align-items: flex-end;
    justify-content: center;
    width: 100%;
}

.code-selector-wrapper {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 240px;
    flex: 2;
    max-width: 360px;
}

.code-selector-wrapper label,
.date-control label,
.article-filter-wrapper label {
    font-size: 0.72rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.code-selector-wrapper input,
.article-filter-wrapper input {
    width: 100%;
}

.date-control {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

/* Article filter */
.article-filter-wrapper {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 160px;
    flex: 1;
    max-width: 260px;
}

select, input[type="date"], input[type="text"] {
    padding: 3px 6px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    color: var(--color-text);
    background: var(--color-bg);
    min-width: 0;
    height: 28px;
    box-sizing: border-box;
}

select:focus, input[type="date"]:focus, input[type="text"]:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 2px rgba(40, 108, 68, 0.15);
}

select:disabled, input[type="text"]:disabled {
    background-color: var(--color-bg-secondary);
    cursor: not-allowed;
}

/* Toggle switch */
.mode-toggle-container {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    user-select: none;
    padding: 0 var(--spacing-sm);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-bg);
    height: 28px;
    box-sizing: border-box;
}

.mode-label {
    font-size: 0.78rem;
    color: var(--color-text);
    transition: color 0.2s ease;
    white-space: nowrap;
}

.toggle-switch {
    width: 36px;
    height: 18px;
    background: var(--color-border);
    border-radius: 9px;
    position: relative;
    transition: background 0.2s ease;
    flex-shrink: 0;
}

.toggle-slider {
    width: 14px;
    height: 14px;
    background: white;
    border-radius: 50%;
    position: absolute;
    top: 2px;
    left: 2px;
    transition: transform 0.2s ease;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.mode-toggle-container.mode-changes .toggle-slider {
    transform: translateX(18px);
}

.mode-toggle-container.mode-changes .toggle-switch {
    background: var(--color-primary);
}

/* Primary button */
.btn-primary {
    padding: 3px var(--spacing-md);
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s ease;
    height: 28px;
    box-sizing: border-box;
}

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

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

/* Secondary button (Print button) */
.btn-secondary {
    padding: 0 var(--spacing-md);
    background: white;
    color: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 28px;
    box-sizing: border-box;
    white-space: nowrap;
}

.btn-secondary:hover {
    background: var(--color-bg-secondary);
    border-color: var(--color-primary);
}

/* Loading */
.loading {
    text-align: center;
    padding: var(--spacing-xl);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto var(--spacing-md);
}

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

/* Error */
.error {
    background: var(--color-del-bg);
    border: 1px solid var(--color-del-border);
    color: var(--color-del-text);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-lg);
}

/* Hidden utility */
.hidden {
    display: none !important;
}

/* Results */
.results {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

/* Before/After View */
.view-before-after {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 110px);
    min-height: 400px;
}

.diff-header {
    display: flex;
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
}

.diff-header-left, .diff-header-right {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    font-weight: 500;
    font-size: 0.875rem;
}

.diff-header-right {
    border-left: 1px solid var(--color-border);
}

.diff-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.diff-pane {
    flex: 1;
    overflow-y: auto;
    padding: 0;
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.7;
}

.diff-right {
    border-left: 1px solid var(--color-border);
}

/* Diff lines */
.diff-line {
    padding: 2px var(--spacing-md);
    white-space: pre-wrap;
    word-wrap: break-word;
}

.diff-line-number {
    display: inline-block;
    width: 50px;
    color: var(--color-text-secondary);
    text-align: right;
    padding-right: var(--spacing-sm);
    user-select: none;
    font-size: 0.75rem;
}

.diff-line-add {
    background: var(--color-add-bg);
    color: var(--color-add-text);
}

.diff-line-del {
    background: var(--color-del-bg);
    color: var(--color-del-text);
}

.diff-line-unchanged {
    background: var(--color-unchanged-bg);
}

.diff-line-marker {
    display: inline-block;
    width: 20px;
    font-weight: bold;
}

/* Changes List View */
.view-changes {
    display: flex;
    flex-direction: column;
    height: calc(100vh - 110px);
    min-height: 400px;
}

.changes-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.commits-list {
    width: 350px;
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
    background: var(--color-bg-secondary);
}

.commits-list h3 {
    padding: var(--spacing-md);
    font-size: 0.95rem;
    font-weight: 600;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-bg);
    position: sticky;
    top: 0;
}

.commits-list ul {
    list-style: none;
}

.commits-list li {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    cursor: pointer;
    transition: background 0.15s ease;
}

.commits-list li:hover {
    background: var(--color-bg);
}

.commits-list li.active {
    background: var(--color-bg);
    border-left: 3px solid var(--color-primary);
}

.commit-date {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.commit-message {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.commit-files {
    font-weight: 400;
    color: var(--color-text-secondary);
    font-size: 0.8rem;
}

.commit-detail {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.commit-header {
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
}

.commit-header .placeholder {
    color: var(--color-text-secondary);
    font-style: italic;
}

.commit-header h4 {
    font-size: 0.95rem;
    margin-bottom: var(--spacing-xs);
}

.commit-header .commit-meta {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

.commit-diff {
    flex: 1;
    overflow-y: auto;
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.7;
}

/* File separator in diff */
.diff-file-header {
    background: var(--color-bg-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    font-weight: 600;
    font-size: 0.85rem;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
}

.diff-file-header:first-child {
    border-top: none;
}

/* Article title for before/after view */
.article-title {
    background: var(--color-bg-secondary);
    padding: var(--spacing-md);
    text-align: center;
    font-weight: 600;
    font-size: 0.95rem;
    border-top: 2px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text);
    position: sticky;
    top: 0;
    z-index: 10;
}

.article-diff-section {
    border-bottom: 2px solid var(--color-border);
    margin-bottom: var(--spacing-sm);
}

/* Before/After tables */
.before-after-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--spacing-lg);
}

/* Sticky header for before/after dates */
.before-after-sticky-header {
    display: grid;
    grid-template-columns: 1fr 1fr;
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-bg);
    border-bottom: 2px solid var(--color-border);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-style: italic;
    font-weight: normal;
    text-align: center;
    font-size: 0.85rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.sticky-date-left,
.sticky-date-right {
    padding: var(--spacing-xs);
}

.before-after-table thead th {
    background: var(--color-bg-secondary);
    padding: var(--spacing-md);
    text-align: center;
    font-weight: 600;
    font-size: 0.95rem;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text);
}

.before-after-table tbody td {
    padding: 2px var(--spacing-md);
    white-space: pre-wrap;
    word-wrap: break-word;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
}

.before-after-table tbody td.diff-line-add {
    background: var(--color-add-bg);
    color: var(--color-add-text);
}

.before-after-table tbody td.diff-line-del {
    background: var(--color-del-bg);
    color: var(--color-del-text);
}

.before-after-table tbody td.diff-line-unchanged {
    background: var(--color-unchanged-bg);
}

.before-after-table tbody td.diff-line-empty {
    background: var(--color-bg-secondary);
}

/* File selector */
.file-selector {
    background: var(--color-bg);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.file-selector label {
    font-weight: 500;
    font-size: 0.9rem;
}

.file-selector select {
    flex: 1;
    max-width: 500px;
}

/* Footer */
footer {
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-md) var(--spacing-xl);
    text-align: center;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

footer a {
    color: var(--color-primary);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 900px) {
    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }

    .code-selector-wrapper,
    .article-filter-wrapper {
        max-width: none;
        flex: none;
        min-width: auto;
    }

    .date-control,
    .code-selector-wrapper,
    .article-filter-wrapper {
        width: 100%;
    }

    select, input[type="date"], input[type="text"] {
        width: 100%;
        min-width: auto;
    }

    .mode-toggle-container {
        justify-content: center;
        height: auto;
        padding: var(--spacing-xs) var(--spacing-sm);
    }

    .btn-secondary {
        width: 100%;
        height: auto;
        padding: var(--spacing-xs) var(--spacing-sm);
    }

    .changes-container {
        flex-direction: column;
    }

    .commits-list {
        width: 100%;
        max-height: 200px;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
    }

    .diff-container {
        flex-direction: column;
    }

    .diff-pane {
        min-height: 200px;
    }

    .diff-right {
        border-left: none;
        border-top: 1px solid var(--color-border);
    }
}

/* Stats badges */
.commit-stats {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xs);
    font-size: 0.75rem;
}

.stat-add {
    color: var(--color-add-text);
}

.stat-del {
    color: var(--color-del-text);
}

/* No results */
.no-results {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-text-secondary);
}

.no-results p {
    margin-bottom: var(--spacing-sm);
}

/* CORS notice */
.cors-notice {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-text-secondary);
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    margin: var(--spacing-md);
}

.cors-notice p {
    margin-bottom: var(--spacing-md);
}

.btn-external {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: background 0.15s ease;
}

.btn-external:hover {
    background: var(--color-primary-hover);
    text-decoration: none;
}

/* External link in header */
.external-link {
    margin-left: var(--spacing-sm);
    color: var(--color-primary);
    text-decoration: none;
    font-size: 0.8rem;
}

.external-link:hover {
    text-decoration: underline;
}

/* Print header (hidden on screen, visible on print) */
.print-header {
    display: none;
}

/* Print styles */
@media print {
    /* Show print header */
    .print-header {
        display: block !important;
        margin-bottom: 2em;
        padding-bottom: 1em;
        border-bottom: 2px solid #333;
    }

    .print-header h1 {
        margin: 0 0 0.5em 0;
        font-size: 1.5em;
        color: #333;
    }

    .print-header p {
        margin: 0.25em 0;
        color: #666;
        font-size: 0.9em;
    }

    /* Hide UI elements */
    header,
    .controls,
    #loading,
    #error,
    .btn-primary,
    .btn-secondary,
    .mode-toggle-container,
    .commits-list {
        display: none !important;
    }

    /* Reduce font size for printing */
    .diff-pane,
    .commit-diff,
    .before-after-table {
        font-size: 0.75rem !important;
        line-height: 1.4 !important;
    }

    .diff-line-content,
    .before-after-table tbody td {
        font-size: 0.75rem !important;
    }

    /* Optimize page layout */
    body {
        background: white;
        margin: 0;
        padding: 0;
    }

    main {
        max-width: 100%;
        padding: 0;
        margin: 0;
    }

    .results {
        border: none;
        border-radius: 0;
    }

    /* Print before/after view */
    .view-before-after {
        height: auto !important;
        min-height: auto !important;
        overflow: visible !important;
    }

    .view-changes {
        height: auto !important;
        min-height: auto !important;
        overflow: visible !important;
    }

    .diff-pane {
        overflow: visible !important;
        height: auto !important;
        max-height: none !important;
    }

    .commit-diff {
        overflow: visible !important;
        height: auto !important;
        max-height: none !important;
    }

    .commit-detail {
        overflow: visible !important;
        height: auto !important;
        max-height: none !important;
    }

    .changes-container {
        overflow: visible !important;
        height: auto !important;
        max-height: none !important;
    }

    .before-after-sticky-header {
        position: static;
        page-break-after: avoid;
    }

    .before-after-table {
        page-break-inside: auto;
    }

    .before-after-table thead th {
        background: #f0f0f0 !important;
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }

    .before-after-table tbody tr {
        page-break-inside: avoid;
        page-break-after: auto;
    }

    /* Print changes list view */
    .commit-header {
        page-break-after: avoid;
    }

    .diff-file-header {
        page-break-after: avoid;
        background: #f0f0f0 !important;
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }

    /* Print colors */
    .diff-line-add,
    .before-after-table tbody td.diff-line-add {
        background: #e8f5e9 !important;
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }

    .diff-line-del,
    .before-after-table tbody td.diff-line-del {
        background: #ffebee !important;
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }
}