/* CSS Variables */
:root {
    /* Colors */
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;
    --color-border: #e5e5e5;
    --color-border-light: #f0f0f0;
    --color-accent: #0066cc;
    --color-accent-hover: #0052a3;
    --color-success: #22c55e;
    --color-error: #ef4444;
    --color-warning: #f59e0b;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 4rem;

    /* Layout */
    --max-width-content: 65ch;
    --max-width-page: 1200px;
    --header-height: 60px;
}

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

html {
    font-size: 18px;
    line-height: 1.6;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.3;
    font-weight: 600;
}

h1 { font-size: 2.5rem; letter-spacing: -0.02em; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.25rem; }

p { margin-bottom: var(--space-md); }

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

a:hover {
    text-decoration: underline;
}

code, pre {
    font-family: var(--font-mono);
    font-size: 0.9em;
}

code {
    background: var(--color-border-light);
    padding: 0.15em 0.4em;
    border-radius: 4px;
}

pre {
    background: #1a1a1a;
    color: #f0f0f0;
    padding: var(--space-md);
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: var(--space-md);
}

pre code {
    background: none;
    padding: 0;
}

img {
    max-width: 100%;
    height: auto;
}

/* Layout */
.container {
    max-width: var(--max-width-page);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.prose {
    max-width: var(--max-width-content);
}

.prose h1 { margin-bottom: var(--space-lg); }
.prose h2 { margin-top: var(--space-xl); margin-bottom: var(--space-md); }
.prose h3 { margin-top: var(--space-lg); margin-bottom: var(--space-sm); }

/* Site Header */
.site-header {
    height: var(--header-height);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    background: var(--color-bg);
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.site-logo {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--color-text);
}

.site-logo:hover {
    text-decoration: none;
}

.site-nav {
    display: flex;
    gap: var(--space-lg);
}

.site-nav a {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

.site-nav a:hover {
    color: var(--color-text);
    text-decoration: none;
}

/* Site Main */
.site-main {
    padding: var(--space-xl) 0;
    min-height: calc(100vh - var(--header-height) - 200px);
}

/* Site Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--space-xl) 0;
}

.site-footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
}

.social-links {
    display: flex;
    gap: var(--space-md);
}

.social-links a {
    color: var(--color-text-secondary);
    transition: color 0.2s;
}

.social-links a:hover {
    color: var(--color-text);
}

.copyright {
    color: var(--color-text-muted);
    font-size: 0.85rem;
}

/* Hero */
.hero {
    text-align: center;
    padding: var(--space-xl) 0;
    margin-bottom: var(--space-xl);
}

.hero h1 {
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 50ch;
    margin: 0 auto;
}

/* Sections */
.section {
    margin-bottom: var(--space-xl);
}

.section h2 {
    margin-bottom: var(--space-lg);
}

.section-link {
    margin-top: var(--space-lg);
}

/* Project Grid */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.project-card {
    border: 1px solid var(--color-border);
    border-radius: 8px;
    overflow: hidden;
    transition: box-shadow 0.2s;
}

.project-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.project-thumbnail {
    width: 100%;
    aspect-ratio: 16/9;
    object-fit: cover;
}

.project-card-content {
    padding: var(--space-md);
}

.project-card h2,
.project-card h3 {
    margin-bottom: var(--space-sm);
}

.project-card h2 a,
.project-card h3 a {
    color: var(--color-text);
}

.project-card h2 a:hover,
.project-card h3 a:hover {
    color: var(--color-accent);
    text-decoration: none;
}

.project-card p {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    margin-bottom: var(--space-sm);
}

.project-type {
    display: inline-block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: var(--space-xs);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
}

/* Tags */
.tag {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.2em 0.6em;
    background: var(--color-border-light);
    border-radius: 4px;
    color: var(--color-text-secondary);
}

a.tag:hover {
    background: var(--color-border);
    text-decoration: none;
}

/* Post List */
.post-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.post-card {
    border-bottom: 1px solid var(--color-border-light);
    padding-bottom: var(--space-lg);
}

.post-card:last-child {
    border-bottom: none;
}

.post-card time {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.post-card h2,
.post-card h3 {
    margin: var(--space-xs) 0 var(--space-sm);
}

.post-card h2 a,
.post-card h3 a {
    color: var(--color-text);
}

.post-card h2 a:hover,
.post-card h3 a:hover {
    color: var(--color-accent);
    text-decoration: none;
}

.post-card p {
    color: var(--color-text-secondary);
}

.post-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-top: var(--space-sm);
}

/* Blog Post */
.blog-post .post-header {
    margin-bottom: var(--space-xl);
}

.blog-post .post-header time {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.blog-post .post-header h1 {
    margin: var(--space-sm) 0 var(--space-md);
}

.post-content {
    margin-bottom: var(--space-xl);
}

.post-footer {
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

/* Project Detail */
.project-detail .project-header {
    margin-bottom: var(--space-xl);
}

.project-detail .project-description {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.project-links {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.project-hero-image {
    width: 100%;
    border-radius: 8px;
    margin-bottom: var(--space-xl);
}

.project-content {
    margin-bottom: var(--space-xl);
}

.project-footer {
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

/* Portfolio Filters */
.portfolio-filters {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.portfolio-filters a {
    color: var(--color-text-secondary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: 4px;
}

.portfolio-filters a:hover {
    text-decoration: none;
    background: var(--color-border-light);
}

.portfolio-filters a.active {
    color: var(--color-text);
    background: var(--color-border-light);
    font-weight: 500;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.6em 1.2em;
    background: var(--color-border-light);
    color: var(--color-text);
    border: none;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s;
    text-decoration: none;
}

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

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

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

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

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

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

.btn-danger:hover {
    background: #dc2626;
}

.btn-small {
    padding: 0.3em 0.8em;
    font-size: 0.85rem;
}

/* Empty State */
.empty-state {
    text-align: center;
    color: var(--color-text-muted);
    padding: var(--space-xl) 0;
}

/* Alerts */
.alert {
    padding: var(--space-md);
    border-radius: 6px;
    margin-bottom: var(--space-lg);
}

.alert-error {
    background: #fef2f2;
    color: var(--color-error);
    border: 1px solid #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: #15803d;
    border: 1px solid #bbf7d0;
}

/* ==================== */
/* Admin Styles */
/* ==================== */

.admin-login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f5f5f5;
}

.login-container {
    background: white;
    padding: var(--space-xl);
    border-radius: 8px;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.login-container h1 {
    margin-bottom: var(--space-lg);
    text-align: center;
}

.login-form .form-group {
    margin-bottom: var(--space-md);
}

.login-form .btn {
    width: 100%;
    margin-top: var(--space-md);
}

.login-back {
    text-align: center;
    margin-top: var(--space-lg);
    font-size: 0.9rem;
}

/* Admin Layout */
.admin-page {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: 240px;
    background: #1a1a1a;
    color: white;
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
}

.admin-logo {
    padding: var(--space-lg);
    border-bottom: 1px solid #333;
}

.admin-logo a {
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
}

.admin-logo a:hover {
    text-decoration: none;
}

.admin-nav {
    flex: 1;
    padding: var(--space-md) 0;
}

.admin-nav a {
    display: block;
    padding: var(--space-sm) var(--space-lg);
    color: #999;
    transition: all 0.2s;
}

.admin-nav a:hover {
    color: white;
    background: #333;
    text-decoration: none;
}

.admin-nav a.active {
    color: white;
    background: #333;
}

.admin-sidebar-footer {
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid #333;
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.admin-sidebar-footer a {
    color: #999;
    font-size: 0.9rem;
}

.admin-sidebar-footer a:hover {
    color: white;
    text-decoration: none;
}

.admin-main {
    flex: 1;
    margin-left: 240px;
    background: #f5f5f5;
}

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

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

.admin-content {
    padding: var(--space-lg);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.stat-card {
    background: white;
    padding: var(--space-lg);
    border-radius: 8px;
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 600;
    color: var(--color-accent);
}

.stat-label {
    display: block;
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin-top: var(--space-xs);
}

/* Admin Section */
.admin-section {
    background: white;
    padding: var(--space-lg);
    border-radius: 8px;
    margin-bottom: var(--space-lg);
}

.admin-section h2 {
    font-size: 1.1rem;
    margin-bottom: var(--space-md);
}

.quick-actions {
    display: flex;
    gap: var(--space-md);
}

/* Admin Table */
.admin-table {
    width: 100%;
    background: white;
    border-radius: 8px;
    overflow: hidden;
}

.admin-table th,
.admin-table td {
    padding: var(--space-md);
    text-align: left;
    border-bottom: 1px solid var(--color-border-light);
}

.admin-table th {
    background: #f9f9f9;
    font-weight: 500;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
}

.admin-table tr:last-child td {
    border-bottom: none;
}

.admin-table .actions {
    display: flex;
    gap: var(--space-sm);
}

/* Badges */
.badge {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.2em 0.6em;
    border-radius: 4px;
    background: var(--color-border-light);
    color: var(--color-text-secondary);
}

.badge-success {
    background: #dcfce7;
    color: #15803d;
}

.badge-draft {
    background: #fef3c7;
    color: #92400e;
}

.badge-featured {
    background: #dbeafe;
    color: #1d4ed8;
}

/* Admin Form */
.admin-form {
    background: white;
    padding: var(--space-lg);
    border-radius: 8px;
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--space-xs);
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.6em 0.8em;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    font-family: inherit;
    font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
}

.form-group textarea {
    resize: vertical;
}

.form-row {
    display: flex;
    gap: var(--space-md);
}

.form-row .form-group {
    flex: 1;
}

.form-row .form-group-large {
    flex: 2;
}

.form-checkboxes {
    gap: var(--space-lg);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.checkbox-label input {
    width: auto;
}

.form-actions {
    display: flex;
    gap: var(--space-md);
    margin-top: var(--space-lg);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border-light);
}

/* Responsive */
@media (max-width: 768px) {
    html {
        font-size: 16px;
    }

    .container {
        padding: 0 var(--space-md);
    }

    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.35rem; }

    .site-header {
        height: auto;
    }

    .site-header .container {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--space-sm);
        padding: var(--space-md);
    }

    .site-logo {
        width: 100%;
        text-align: center;
    }

    .site-nav {
        gap: var(--space-md);
        font-size: 0.9rem;
    }

    .hero {
        padding: var(--space-lg) 0;
    }

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

    .hero-subtitle {
        font-size: 1rem;
    }

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


    .project-card-content {
        padding: var(--space-sm);
    }

    .project-card h2,
    .project-card h3 {
        font-size: 1.1rem;
    }

    .project-card p {
        font-size: 0.9rem;
    }

    .section {
        margin-bottom: var(--space-lg);
    }

    .form-row {
        flex-direction: column;
    }

    .admin-sidebar {
        width: 100%;
        position: relative;
    }

    .admin-main {
        margin-left: 0;
    }

    .admin-page {
        flex-direction: column;
    }
}