/* ============================================
   Variables & Reset
   ============================================ */
:root {
    --color-bg: #ffffff;
    --color-bg-secondary: #f6f8fa;
    --color-bg-tertiary: #f0f2f5;
    --color-surface: #ffffff;
    --color-border: #e1e4e8;
    --color-border-light: #eef0f2;
    --color-text: #1a1a2e;
    --color-text-secondary: #586069;
    --color-text-muted: #8b949e;
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-primary-light: #dbeafe;
    --color-accent: #7c3aed;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
    --transition: 0.2s ease;
    --max-width: 1200px;
    --content-width: 780px;
    --feed-width: 680px;
    --nav-height: 56px;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-sans);
    background: var(--color-bg-secondary);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-hover); }
img { max-width: 100%; height: auto; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; font-size: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; }

/* ============================================
   Navigation (minimal top bar)
   ============================================ */
.navbar {
    position: fixed; top: 0; left: 0; right: 0;
    height: var(--nav-height);
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border-light);
    z-index: 1000;
    transition: box-shadow var(--transition);
}
.navbar.scrolled { box-shadow: var(--shadow-sm); }

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto; padding: 0 20px;
    height: 100%;
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 16px;
    align-items: center;
}

.nav-logo {
    display: flex; align-items: center; gap: 8px;
    font-weight: 700; font-size: 1.1rem;
    color: var(--color-text); text-decoration: none;
    white-space: nowrap;
}
.nav-logo:hover { color: var(--color-text); }
.logo-icon { color: var(--color-primary); font-size: 1.2rem; }
.logo-text { }

.nav-search {
    max-width: 480px; margin: 0 auto; width: 100%;
    position: relative;
}
.nav-search-icon {
    position: absolute; left: 12px; top: 50%; transform: translateY(-50%);
    font-size: 0.85rem; color: var(--color-text-muted); pointer-events: none;
}
.nav-search input {
    width: 100%; padding: 7px 14px 7px 36px;
    border: 1px solid var(--color-border);
    border-radius: 100px;
    background: var(--color-bg-secondary);
    font-size: 0.85rem; outline: none;
    transition: border-color var(--transition), box-shadow var(--transition);
}
.nav-search input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
    background: var(--color-bg);
}

.nav-actions { display: flex; gap: 4px; }
.nav-action-btn {
    width: 36px; height: 36px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 50%;
    color: var(--color-text-secondary);
    transition: all var(--transition);
    text-decoration: none;
}
.nav-action-btn:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text);
}

/* Reading progress bar */
.reading-progress {
    position: fixed; top: var(--nav-height); left: 0;
    height: 3px; width: 0;
    background: var(--color-primary);
    z-index: 1001;
    transition: width 0.1s linear;
}

/* ============================================
   App Container
   ============================================ */
.app-container {
    min-height: calc(100vh - var(--nav-height));
    padding-top: var(--nav-height);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition);
    cursor: pointer;
    border: none;
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

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

.btn-secondary:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-1px);
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
    padding: 8px 16px;
}

.btn-ghost:hover {
    background: var(--color-bg-tertiary);
    color: var(--color-text);
}

.btn-danger {
    background: var(--color-danger);
    color: #fff;
}

.btn-danger:hover {
    opacity: 0.9;
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.85rem;
}

.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
}

/* ============================================
   Section Headers
   ============================================ */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.section-header p {
    color: var(--color-text-secondary);
    font-size: 1.05rem;
}

/* ============================================
   Tags
   ============================================ */
.tag {
    padding: 2px 10px;
    background: var(--color-bg-tertiary);
    border-radius: 100px;
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}
.tag-primary {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

/* ============================================
   Feed Layout
   ============================================ */
.feed-page {
    max-width: var(--feed-width);
    margin: 0 auto;
    padding: 16px 16px 80px;
}

.feed-filter-bar {
    position: sticky;
    top: var(--nav-height);
    background: var(--color-bg-secondary);
    z-index: 10;
    padding: 12px 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 8px;
}

.feed-tabs { display: flex; gap: 6px; flex-wrap: wrap; }

.feed-tab {
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    background: var(--color-bg);
    border: 1px solid var(--color-border-light);
    cursor: pointer;
    transition: all var(--transition);
}
.feed-tab:hover { border-color: var(--color-border); }
.feed-tab.active {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

.filter-select-sm {
    padding: 6px 30px 6px 12px;
    border: 1px solid var(--color-border);
    border-radius: 100px;
    background: var(--color-bg);
    font-size: 0.82rem;
    color: var(--color-text);
    cursor: pointer; outline: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' fill='%23586069' viewBox='0 0 16 16'%3E%3Cpath d='M8 12L2 6h12z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
}

.feed-list { display: flex; flex-direction: column; gap: 12px; }

/* ── Feed Item ── */
.feed-item {
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    transition: box-shadow var(--transition);
}
.feed-item:hover { box-shadow: var(--shadow-md); }

.feed-item-header {
    display: flex; align-items: center; gap: 10px;
    margin-bottom: 12px;
}
.feed-avatar {
    width: 36px; height: 36px; border-radius: 50%;
    background: var(--color-primary-light);
    color: var(--color-primary);
    display: flex; align-items: center; justify-content: center;
    font-weight: 700; font-size: 0.9rem;
    flex-shrink: 0;
}
.feed-item-meta { display: flex; flex-direction: column; }
.feed-author { font-weight: 600; font-size: 0.88rem; color: var(--color-text); }
.feed-date { font-size: 0.78rem; color: var(--color-text-muted); }

.feed-item-body {
    display: block; text-decoration: none; color: inherit;
    margin-bottom: 12px;
}
.feed-item-body:hover .feed-item-title { color: var(--color-primary); }

.feed-item-title {
    font-size: 1.2rem; font-weight: 700; line-height: 1.35;
    margin-bottom: 6px; color: var(--color-text);
    transition: color var(--transition);
}
.feed-item-excerpt {
    font-size: 0.9rem; color: var(--color-text-secondary);
    line-height: 1.6;
    display: -webkit-box; -webkit-line-clamp: 3;
    -webkit-box-orient: vertical; overflow: hidden;
}

/* Feed media zones */
.feed-image {
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: 12px;
}
.feed-image img {
    width: 100%;
    max-height: 360px;
    object-fit: cover;
}

.feed-item-footer {
    display: flex; align-items: center;
    justify-content: space-between;
    gap: 12px; flex-wrap: wrap;
    padding-top: 12px;
    border-top: 1px solid var(--color-border-light);
}
.feed-item-tags { display: flex; gap: 6px; flex-wrap: wrap; }
.feed-item-actions { display: flex; align-items: center; gap: 12px; }
.feed-read-more {
    font-size: 0.85rem; font-weight: 600; color: var(--color-primary);
}
.feed-read-more:hover { text-decoration: underline; }

/* Type badges in feed */
.feed-type-badge {
    display: inline-block;
    padding: 1px 8px;
    border-radius: 100px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    vertical-align: middle;
    margin-left: 4px;
}
.feed-type-pdf { background: rgba(239,68,68,0.12); color: var(--color-danger); }
.feed-type-repo { background: rgba(37,99,235,0.1); color: var(--color-primary); }

.feed-repo-link {
    display: inline-flex; align-items: center; gap: 4px;
    font-size: 0.85rem; font-weight: 600;
    color: var(--color-primary);
}
.feed-repo-link:hover { text-decoration: underline; }

/* ============================================
   Media Embeds
   ============================================ */
.media-embed { border-radius: var(--radius-md); overflow: hidden; margin-bottom: 12px; }

.media-youtube {
    position: relative; padding-bottom: 56.25%; height: 0;
}
.media-youtube iframe {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    border: 0; border-radius: var(--radius-md);
}

.media-audio {
    padding: 16px; background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
}
.media-audio audio { width: 100%; }

.media-gif img {
    width: 100%; border-radius: var(--radius-md);
}

/* ============================================
   Inline PDF Carousel (in feed)
   ============================================ */
.inline-pdf {
    border-radius: var(--radius-md);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border-light);
    overflow: hidden;
    margin-bottom: 12px;
    min-height: 200px;
}
.inline-pdf-loading {
    display: flex; align-items: center; justify-content: center;
    padding: 60px 24px;
}
.inline-pdf-stage {
    position: relative;
    display: flex; align-items: center; justify-content: center;
    padding: 16px;
}
.inline-pdf-stage canvas {
    max-width: 100%; height: auto;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
}
.inline-pdf-controls {
    display: flex; align-items: center; justify-content: space-between;
    padding: 8px 16px 12px;
}
.inline-pdf-info { font-size: 0.82rem; color: var(--color-text-muted); font-weight: 500; }
.inline-pdf-fullscreen {
    font-size: 1.1rem; color: var(--color-text-muted);
    transition: color var(--transition);
}
.inline-pdf-fullscreen:hover { color: var(--color-primary); }
.inline-pdf-error {
    text-align: center; padding: 40px; font-size: 0.9rem;
    color: var(--color-text-muted);
}

/* ============================================
   Post / Article View
   ============================================ */
.post-view {
    max-width: var(--content-width);
    margin: 0 auto;
    padding: 48px 24px 80px;
}

.post-header {
    margin-bottom: 40px;
}

.post-back {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    margin-bottom: 24px;
    text-decoration: none;
}

.post-back:hover {
    color: var(--color-primary);
}

.post-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.post-meta-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    color: var(--color-text-muted);
    font-size: 0.9rem;
    flex-wrap: wrap;
}

.post-meta-divider {
    width: 4px;
    height: 4px;
    background: var(--color-text-muted);
    border-radius: 50%;
}

.post-cover {
    width: 100%;
    max-height: 450px;
    object-fit: cover;
    border-radius: var(--radius-lg);
    margin-bottom: 40px;
}

.post-content {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--color-text);
}

.post-content h1 {
    font-size: 2rem;
    font-weight: 700;
    margin: 48px 0 16px;
    letter-spacing: -0.02em;
}

.post-content h2 {
    font-size: 1.6rem;
    font-weight: 700;
    margin: 40px 0 12px;
    letter-spacing: -0.01em;
}

.post-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 32px 0 12px;
}

.post-content p {
    margin-bottom: 20px;
}

.post-content img {
    border-radius: var(--radius-md);
    margin: 24px 0;
}

.post-content pre {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    padding: 20px;
    overflow-x: auto;
    margin: 24px 0;
    font-size: 0.9rem;
}

.post-content code {
    font-family: var(--font-mono);
    font-size: 0.88em;
}

.post-content :not(pre) > code {
    background: var(--color-bg-tertiary);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.88em;
}

.post-content blockquote {
    border-left: 3px solid var(--color-primary);
    padding: 12px 20px;
    margin: 24px 0;
    background: var(--color-bg-secondary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    color: var(--color-text-secondary);
}

.post-content ul,
.post-content ol {
    margin: 16px 0;
    padding-left: 28px;
}

.post-content li {
    margin-bottom: 8px;
}

.post-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 24px 0;
    font-size: 0.95rem;
}

.post-content th,
.post-content td {
    border: 1px solid var(--color-border);
    padding: 10px 14px;
    text-align: left;
}

.post-content th {
    background: var(--color-bg-secondary);
    font-weight: 600;
}

.post-content hr {
    border: none;
    border-top: 1px solid var(--color-border-light);
    margin: 40px 0;
}

.post-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-top: 40px;
    padding-top: 24px;
    border-top: 1px solid var(--color-border-light);
}

/* Heading anchors */
.heading-anchor {
    color: var(--color-text-muted);
    text-decoration: none;
    margin-right: 6px;
    opacity: 0;
    transition: opacity var(--transition);
    font-weight: 400;
}
.post-content h1:hover .heading-anchor,
.post-content h2:hover .heading-anchor,
.post-content h3:hover .heading-anchor { opacity: 1; }

/* Copy code button */
.code-copy-btn {
    position: absolute;
    top: 8px; right: 8px;
    padding: 4px 10px;
    font-size: 0.75rem;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    opacity: 0;
    transition: opacity var(--transition);
}
.post-content pre:hover .code-copy-btn { opacity: 1; }
.code-copy-btn:hover {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

/* Table of Contents */
.toc {
    position: fixed;
    left: max(16px, calc((100vw - var(--content-width)) / 2 - 240px));
    top: calc(var(--nav-height) + 32px);
    width: 200px;
    max-height: calc(100vh - var(--nav-height) - 64px);
    overflow-y: auto;
    z-index: 50;
}
.toc-header {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}
.toc-link {
    display: block;
    padding: 4px 0;
    font-size: 0.82rem;
    color: var(--color-text-muted);
    text-decoration: none;
    border-left: 2px solid transparent;
    padding-left: 12px;
    transition: all var(--transition);
    line-height: 1.4;
}
.toc-level-3 { padding-left: 24px; font-size: 0.78rem; }
.toc-link:hover { color: var(--color-text); }
.toc-link.active {
    color: var(--color-primary);
    border-left-color: var(--color-primary);
}

/* Related posts */
.related-posts {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--color-border-light);
}
.related-posts h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 16px;
}
.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}
.related-card {
    display: block;
    padding: 16px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all var(--transition);
}
.related-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}
.related-card h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 4px;
    line-height: 1.4;
}
.related-date {
    font-size: 0.78rem;
    color: var(--color-text-muted);
}

/* ============================================
   PDF Viewer
   ============================================ */
.pdf-viewer {
    max-width: 960px;
    margin: 0 auto;
    padding: 32px 24px 80px;
}

.pdf-viewer-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.pdf-viewer-title {
    font-size: 1.4rem;
    font-weight: 700;
}

.pdf-stage {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
    padding: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    min-height: 400px;
}

.pdf-canvas-wrap {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pdf-canvas-wrap canvas {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
}

.pdf-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all var(--transition);
    z-index: 5;
    color: var(--color-text);
}

.pdf-nav:hover:not(:disabled) {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

.pdf-nav:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.pdf-nav-prev {
    left: -22px;
}

.pdf-nav-next {
    right: -22px;
}

.pdf-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 20px;
}

.pdf-page-info {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.pdf-thumbnails {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 16px 4px;
    margin-top: 16px;
    scrollbar-width: thin;
}

.pdf-thumb {
    flex-shrink: 0;
    cursor: pointer;
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    overflow: hidden;
    transition: all var(--transition);
    opacity: 0.6;
}

.pdf-thumb:hover {
    opacity: 0.9;
}

.pdf-thumb.active {
    border-color: var(--color-primary);
    opacity: 1;
}

.pdf-thumb canvas {
    display: block;
    height: 72px;
    width: auto;
}

.pdf-loading,
.pdf-error {
    text-align: center;
    padding: 60px 24px;
    color: var(--color-text-secondary);
}

.pdf-error {
    color: var(--color-danger);
}

/* ============================================
   Admin Panel
   ============================================ */
.admin-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 32px 24px 80px;
}

.admin-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 32px;
    flex-wrap: wrap;
    gap: 16px;
}

.admin-header h1 {
    font-size: 1.8rem;
    font-weight: 700;
}

.admin-auth {
    max-width: 500px;
    margin: 80px auto;
    text-align: center;
    padding: 48px 32px;
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border-light);
}

.admin-auth h2 {
    margin-bottom: 8px;
}

.admin-auth p {
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    font-size: 0.95rem;
}

.admin-auth .form-group {
    text-align: left;
}

.admin-tabs {
    display: flex;
    gap: 4px;
    border-bottom: 1px solid var(--color-border-light);
    margin-bottom: 24px;
}

.admin-tab {
    padding: 10px 20px;
    color: var(--color-text-secondary);
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all var(--transition);
    cursor: pointer;
    background: none;
    border-top: none;
    border-left: none;
    border-right: none;
}

.admin-tab:hover {
    color: var(--color-text);
}

.admin-tab.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

.admin-posts-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.admin-post-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 16px 20px;
    background: var(--color-surface);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-md);
    transition: all var(--transition);
}

.admin-post-item:hover {
    border-color: var(--color-border);
    box-shadow: var(--shadow-sm);
}

.admin-post-info h4 {
    font-weight: 600;
    margin-bottom: 4px;
}

.admin-post-info p {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.admin-post-actions {
    display: flex;
    gap: 8px;
}

/* ============================================
   Editor
   ============================================ */
.editor-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 32px 24px 80px;
}

.editor-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.editor-toolbar-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.editor-toolbar-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    font-size: 0.9rem;
    color: var(--color-text);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    background: var(--color-surface);
    transition: border-color var(--transition);
    outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.editor-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    min-height: 500px;
}

.editor-pane {
    display: flex;
    flex-direction: column;
}

.editor-pane-header {
    padding: 10px 16px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border-light);
    border-bottom: none;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.editor-textarea {
    flex: 1;
    width: 100%;
    padding: 20px;
    border: 1px solid var(--color-border-light);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.7;
    resize: none;
    outline: none;
    tab-size: 4;
}

.editor-textarea:focus {
    border-color: var(--color-primary);
}

.editor-preview {
    flex: 1;
    padding: 20px;
    border: 1px solid var(--color-border-light);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    overflow-y: auto;
    line-height: 1.7;
}

.editor-meta {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 24px;
    padding: 20px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border-light);
}

.editor-meta .form-group {
    margin-bottom: 0;
}

/* File Upload */
.file-upload-area {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-md);
    padding: 32px;
    text-align: center;
    transition: all var(--transition);
    cursor: pointer;
}

.file-upload-area:hover,
.file-upload-area.drag-over {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}

.file-upload-area p {
    color: var(--color-text-secondary);
    margin-top: 8px;
    font-size: 0.9rem;
}

.file-upload-icon {
    font-size: 2rem;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}

.upload-progress {
    margin-top: 16px;
    background: var(--color-bg-tertiary);
    border-radius: 100px;
    height: 6px;
    overflow: hidden;
}

.upload-progress-bar {
    height: 100%;
    background: var(--color-primary);
    border-radius: 100px;
    transition: width 0.3s ease;
}

.uploaded-files {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
}

.uploaded-file {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: var(--color-bg-secondary);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
}

.uploaded-file-remove {
    cursor: pointer;
    color: var(--color-danger);
    font-weight: 700;
}

/* ============================================
   Loading & Empty States
   ============================================ */
.loading-state {
    text-align: center;
    padding: 60px 24px;
}

.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 16px;
}

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

.loading-text {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

.empty-state {
    text-align: center;
    padding: 80px 24px;
    color: var(--color-text-secondary);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state h3 {
    margin-bottom: 8px;
    color: var(--color-text);
}

/* ============================================
   Footer (simplified)
   ============================================ */
.footer {
    background: var(--color-bg);
    border-top: 1px solid var(--color-border-light);
    padding: 32px 0 20px;
    margin-top: 60px;
}
.footer-container {
    max-width: var(--feed-width);
    margin: 0 auto; padding: 0 16px;
}
.footer-content {
    display: flex; align-items: flex-start;
    justify-content: space-between; gap: 24px;
    margin-bottom: 20px; flex-wrap: wrap;
}
.footer-logo {
    font-weight: 700; font-size: 1rem;
    color: var(--color-text); text-decoration: none;
    display: flex; align-items: center; gap: 6px;
    margin-bottom: 6px;
}
.footer-logo:hover { color: var(--color-text); }
.footer-left .footer-text {
    color: var(--color-text-muted); font-size: 0.85rem;
    max-width: 340px; line-height: 1.5;
}
.footer-links {
    display: flex; gap: 16px; flex-wrap: wrap;
}
.footer-links a {
    color: var(--color-text-secondary); font-size: 0.85rem;
}
.footer-links a:hover { color: var(--color-primary); }
.footer-bottom {
    padding-top: 16px;
    border-top: 1px solid var(--color-border-light);
    text-align: center;
    color: var(--color-text-muted); font-size: 0.8rem;
}

/* ============================================
   Back to Top
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 50%;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--color-text);
    box-shadow: var(--shadow-md);
    transition: all var(--transition);
    z-index: 100;
    cursor: pointer;
}

.back-to-top:hover {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

.back-to-top.visible {
    display: flex;
}

/* ============================================
   Toast Notifications
   ============================================ */
.toast-container {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    padding: 12px 20px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    color: #fff;
    box-shadow: var(--shadow-lg);
    animation: toastIn 0.3s ease;
    white-space: nowrap;
}

.toast-success {
    background: var(--color-success);
}

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

.toast-info {
    background: var(--color-primary);
}

@keyframes toastIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.toast-exit {
    animation: toastOut 0.3s ease forwards;
}

@keyframes toastOut {
    to {
        opacity: 0;
        transform: translateY(-10px);
    }
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
    .nav-search { max-width: 100%; }
    .logo-text { display: none; }

    .post-title { font-size: 1.8rem; }
    .post-content { font-size: 1rem; }

    .editor-split { grid-template-columns: 1fr; }
    .editor-meta { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }

    .pdf-nav-prev { left: 4px; }
    .pdf-nav-next { right: 4px; }

    .admin-post-item { flex-direction: column; align-items: flex-start; }

    .footer-content { flex-direction: column; }

    /* Hide TOC on smaller screens */
    .toc { display: none; }
}

@media (max-width: 480px) {
    .feed-filter-bar { flex-direction: column; align-items: flex-start; }
    .feed-item { padding: 16px; }
    .feed-item-title { font-size: 1.05rem; }
    .nav-container { gap: 8px; }
}