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

:root {
    --bg:        #f9f7f4;
    --surface:   #ffffff;
    --sidebar-bg:#ffffff;
    --sidebar-w: 272px;

    --text:      #1c1917;
    --text-2:    #6b6560;
    --text-inv:  #1c1917;
    --text-inv2: #6b6560;

    --accent:    #c8622a;
    --accent-lt: #f4ede6;
    --border:    #e8e4de;
    --border-dark: #e8e4de;

    --radius:    8px;
    --font-sans: 'Fira Sans', system-ui, sans-serif;
    --font-serif: 'Fira Sans', Georgia, serif;
    --font-mono: 'Fira Sans', 'Courier New', monospace;
    --transition: 200ms ease;
}

html { font-size: 18px; }

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    height: 100dvh;
    overflow: hidden;
    line-height: 1.7;
}

/* ─── App Shell ─────────────────────────────────────────────── */
.app-shell {
    display: flex;
    height: 100dvh;
    overflow: hidden;
}

/* ─── Sidebar ───────────────────────────────────────────────── */
.sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    height: 100dvh;
    overflow: hidden;
    transition: transform var(--transition), background var(--transition);
    z-index: 100;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 20px 16px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

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

.brand-name {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--text-inv);
    letter-spacing: -0.01em;
    line-height: 1;
}

.brand-tag {
    font-size: 0.85rem;
    color: var(--text-inv2);
    font-weight: 300;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-inv2);
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    display: flex;
    transition: color var(--transition);
}
.sidebar-toggle:hover { color: var(--text-inv); }

/* Desktop sidebar collapsed state */
.sidebar.collapsed {
    width: 60px;
}

.sidebar.collapsed .brand-name,
.sidebar.collapsed .brand-tag,
.sidebar.collapsed .search-wrap,
.sidebar.collapsed .nav-controls,
.sidebar.collapsed .sidebar-nav-links,
.sidebar.collapsed .course-nav,
.sidebar.collapsed .course-label-text,
.sidebar.collapsed .unit-code {
    display: none;
}

.sidebar.collapsed .sidebar-header {
    justify-content: center;
    padding: 20px 10px 16px;
}

.sidebar.collapsed .course-group {
    position: relative;
}

.sidebar.collapsed .course-label {
    padding: 12px 10px;
    justify-content: center;
}

.sidebar.collapsed .course-chevron {
    display: none;
}

.sidebar.collapsed .unit-list.visible {
    position: absolute;
    left: 60px;
    top: 0;
    width: 250px;
    background: var(--sidebar-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 100;
    padding: 8px 0;
    max-height: 400px;
    overflow-y: auto;
}

.sidebar.collapsed .unit-item {
    padding: 10px 16px;
    font-size: 0.85rem;
}

/* Search */
.search-wrap {
    position: relative;
    padding: 14px 16px;
    flex-shrink: 0;
}

.search-icon {
    position: absolute;
    left: 28px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-inv2);
    pointer-events: none;
}

#searchInput {
    width: 100%;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 10px 14px 10px 38px;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text-inv);
    outline: none;
    transition: border-color var(--transition), background var(--transition);
}
#searchInput::placeholder { color: var(--text-inv2); }
#searchInput:focus {
    border-color: var(--accent);
    background: var(--surface);
}

/* Course Nav */
.course-nav {
    flex: 1;
    overflow-y: auto;
    padding: 8px 0 20px;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}
.course-nav::-webkit-scrollbar { width: 4px; }
.course-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.nav-loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 40px 20px;
    color: var(--text-inv2);
    font-size: 0.95rem;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Course group */
.course-group { margin-bottom: 4px; }

.course-label {
    width: 100%;
    background: none;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px 10px 20px;
    color: var(--text-inv2);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.03em;
    text-align: left;
    transition: color var(--transition);
    gap: 8px;
}
.course-label:hover { color: var(--text-inv); }
.course-label.open { color: var(--text-inv); }

.course-label-text { flex: 1; line-height: 1.3; }

.course-chevron {
    flex-shrink: 0;
    transition: transform var(--transition);
    opacity: 0.5;
}
.course-label.open .course-chevron { transform: rotate(90deg); opacity: 1; }

/* Units list */
.unit-list {
    display: none;
    padding-bottom: 4px;
}
.unit-list.visible { display: block; }

.unit-item {
    display: block;
    width: 100%;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px 16px 8px 28px;
    text-align: left;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text-inv2);
    border-left: 2px solid transparent;
    transition: color var(--transition), border-color var(--transition), background var(--transition);
    line-height: 1.4;
}
.unit-item:hover {
    color: var(--text-inv);
    background: rgba(0,0,0,0.04);
}
.unit-item.active {
    color: var(--accent);
    border-left-color: var(--accent);
    background: rgba(200, 98, 42, 0.08);
}

.unit-code {
    display: block;
    font-size: 0.8rem;
    opacity: 0.55;
    margin-top: 2px;
    font-weight: 300;
}

/* ─── Main Content ──────────────────────────────────────────── */
.main-content {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    height: 100dvh;
    overflow: hidden;
}

.topbar {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 0 32px;
    height: 56px;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    flex-shrink: 0;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-2);
    padding: 4px;
    border-radius: 4px;
}

.breadcrumb {
    font-size: 1rem;
    color: var(--text-2);
    display: flex;
    align-items: center;
    gap: 6px;
    flex: 1;
    min-width: 0;
    overflow: hidden;
}
.breadcrumb .bc-course { color: var(--text-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.breadcrumb .bc-sep { opacity: 0.4; flex-shrink: 0; }
.breadcrumb .bc-unit { color: var(--text); font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* Content area */
.content-area {
    flex: 1;
    overflow-y: auto;
    padding: 40px 48px;
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
}
.content-area::-webkit-scrollbar { width: 6px; }
.content-area::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* Welcome */
.welcome-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 60vh;
    text-align: center;
    gap: 12px;
    color: var(--text-2);
    padding-top: 10vh;
}
.welcome-icon {
    color: var(--border);
    margin-bottom: 8px;
}
.welcome-state h2 {
    font-family: var(--font-serif);
    font-size: 2.2rem;
    font-weight: 400;
    color: var(--text);
    line-height: 1.15;
    letter-spacing: -0.02em;
}
.welcome-state p { font-size: 1.15rem; margin-bottom: 8px; }

/* Recently Updated Section */
.recently-updated {
    width: 100%;
    max-width: 800px;
    margin-top: 32px;
    text-align: left;
}

.recently-updated h3 {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-2);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.recent-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 12px;
}

.recent-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
    cursor: pointer;
    transition: all var(--transition);
    text-align: left;
}

.recent-card:hover {
    border-color: var(--accent);
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.recent-card .course-name {
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 6px;
}

.recent-card .unit-title {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--text);
    line-height: 1.3;
    margin-bottom: 4px;
}

.recent-card .unit-code {
    font-size: 0.9rem;
    color: var(--text-2);
    font-weight: 400;
}

.recent-skeleton {
    grid-column: 1 / -1;
    text-align: center;
    padding: 40px;
    color: var(--text-2);
    font-size: 1rem;
}

.recent-empty {
    grid-column: 1 / -1;
    text-align: center;
    padding: 32px;
    color: var(--text-2);
    font-size: 1rem;
    font-style: italic;
}

/* Loading state */
.loading-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 50vh;
    gap: 12px;
    color: var(--text-2);
    font-size: 1rem;
}
.loading-state .spinner {
    border-color: var(--border);
    border-top-color: var(--accent);
}

/* Error state */
.error-state {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 50vh;
    color: var(--text-2);
    font-size: 1rem;
}

/* ─── Unit Content ──────────────────────────────────────────── */
.unit-header {
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border);
}

.unit-header .course-label-text {
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 6px;
    display: block;
}

.unit-header h1 {
    font-family: var(--font-serif);
    font-size: 2.8rem;
    font-weight: 400;
    color: var(--text);
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 6px;
}

.unit-header .unit-meta {
    font-size: 1rem;
    color: var(--text-2);
}

/* Notes tabs */
.notes-tabs {
    display: flex;
    gap: 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 32px;
    overflow-x: auto;
    scrollbar-width: none;
}
.notes-tabs::-webkit-scrollbar { display: none; }

.note-tab-btn {
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    padding: 12px 20px;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-2);
    cursor: pointer;
    white-space: nowrap;
    transition: color var(--transition), border-color var(--transition);
}
.note-tab-btn:hover { color: var(--text); }
.note-tab-btn.active {
    color: var(--text);
    border-bottom-color: var(--accent);
    font-weight: 500;
}

/* Page pills */
.page-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 28px;
}
.page-pill {
    background: none;
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 6px 16px;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text-2);
    cursor: pointer;
    transition: all var(--transition);
}
.page-pill:hover { border-color: var(--accent); color: var(--accent); }
.page-pill.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
    font-weight: 500;
}

/* Note panel */
.note-panel { display: none; }
.note-panel.visible { display: block; }

.page-section { display: none; }
.page-section.visible { display: block; }

.page-title {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    font-weight: 400;
    color: var(--text);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
    font-style: italic;
}

/* ─── Markdown body ─────────────────────────────────────────── */
.markdown-body {
    font-family: var(--font-sans);
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--text);
    max-width: 72ch;
}

.markdown-body h1, .markdown-body h2, .markdown-body h3,
.markdown-body h4, .markdown-body h5, .markdown-body h6 {
    font-family: var(--font-serif);
    font-weight: 400;
    color: var(--text);
    margin: 1.8em 0 0.6em;
    line-height: 1.2;
    letter-spacing: -0.01em;
}
.markdown-body h1 { font-size: 2.4rem; }
.markdown-body h2 { font-size: 1.9rem; }
.markdown-body h3 { font-size: 1.5rem; }

.markdown-body p { margin: 0 0 1em; }
.markdown-body ul, .markdown-body ol { margin: 0 0 1em 1.4em; }
.markdown-body li { margin-bottom: 0.3em; }

.markdown-body strong { font-weight: 600; }
.markdown-body em { font-style: italic; }

.markdown-body code {
    background: var(--accent-lt);
    color: var(--accent);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.85em;
    font-family: var(--font-mono);
}

.markdown-body pre {
    background: #1a1814;
    color: #e8e4de;
    padding: 20px;
    border-radius: var(--radius);
    overflow-x: auto;
    margin: 0 0 1.2em;
    font-size: 0.82em;
    line-height: 1.6;
    font-family: var(--font-mono);
}
.markdown-body pre code { background: none; color: inherit; padding: 0; font-family: var(--font-mono); }

.markdown-body blockquote {
    border-left: 3px solid var(--accent);
    padding: 4px 0 4px 20px;
    margin: 0 0 1em;
    color: var(--text-2);
    font-style: italic;
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2em 0;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 0 0 1.2em;
    font-size: 0.875em;
}
.markdown-body th, .markdown-body td {
    padding: 10px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}
.markdown-body th {
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-2);
}
.markdown-body tr:last-child td { border-bottom: none; }

.markdown-body a { color: var(--accent); text-decoration: none; }
.markdown-body a:hover { text-decoration: underline; }

.markdown-body img { max-width: 100%; border-radius: var(--radius); margin: 0.5em 0; }

/* ─── Footer ────────────────────────────────────────────────── */
.site-footer {
    padding: 16px 32px;
    border-top: 1px solid var(--border);
    background: var(--surface);
    color: var(--text-2);
    font-size: 0.85rem;
    flex-shrink: 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.footer-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-links a {
    color: var(--text-2);
    text-decoration: none;
    transition: color var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
}

.footer-links .sep {
    color: var(--border);
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    .site-footer { padding: 16px 20px; }
}

/* ─── Overlay (mobile) ──────────────────────────────────────── */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 90;
    backdrop-filter: blur(2px);
}

/* ─── Skeleton Loading ──────────────────────────────────────── */
.skeleton {
    background: linear-gradient(90deg, var(--border) 25%, var(--surface) 50%, var(--border) 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
    border-radius: 4px;
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
}

.skeleton-card .skeleton {
    height: 16px;
    margin-bottom: 8px;
}

.skeleton-card .course-name { width: 40%; margin-bottom: 12px; }
.skeleton-card .unit-title { width: 80%; height: 24px; margin-bottom: 8px; }
.skeleton-card .unit-code { width: 30%; }

.skeleton-content {
    padding: 32px 0;
}

/* ─── Error State ─────────────────────────────────────────── */
.error-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 40vh;
    gap: 16px;
    color: var(--text-2);
    text-align: center;
    padding: 40px;
}

.error-icon {
    color: var(--text-2);
    opacity: 0.5;
}

.retry-btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 10px 24px;
    border-radius: var(--radius);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    cursor: pointer;
    transition: background var(--transition);
}

.retry-btn:hover {
    background: #b05520;
}

/* ─── Empty Search State ──────────────────────────────────── */
.nav-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
    gap: 12px;
    color: var(--text-inv2);
}

.nav-empty-text {
    font-size: 0.95rem;
}

.clear-search-btn {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-inv);
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.clear-search-btn:hover {
    background: var(--surface);
    border-color: var(--accent);
}

/* ─── Mobile Sidebar Animation ───────────────────────────── */
.sidebar {
    transition: transform 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-overlay {
    transition: opacity 300ms ease;
    opacity: 0;
}

.sidebar-overlay.visible {
    display: block;
    opacity: 1;
}

/* ─── Reading Progress Indicator ───────────────────────────── */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: var(--accent);
    z-index: 1000;
    transition: width 100ms linear;
}

/* ─── Dark Mode ────────────────────────────────────────────── */
[data-theme="dark"] {
    --bg: #0f0d0b;
    --surface: #1a1814;
    --sidebar-bg: #242220;
    --text: #e8e4de;
    --text-2: #a8a4a0;
    --text-inv: #e8e4de;
    --text-inv2: #8a8480;
    --border: #3a3630;
    --border-dark: #3a3630;
}

[data-theme="dark"] .sidebar {
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
}

[data-theme="dark"] .sidebar-header {
    border-color: var(--border-dark);
}

[data-theme="dark"] #searchInput {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
    color: var(--text-inv);
}

[data-theme="dark"] #searchInput:focus {
    background: rgba(0,0,0,0.3);
}

[data-theme="dark"] .course-nav::-webkit-scrollbar-thumb {
    background: var(--border-dark);
}

[data-theme="dark"] .unit-item:hover {
    background: rgba(255,255,255,0.03);
}

[data-theme="dark"] .nav-control-btn {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
    color: var(--text-inv2);
}

[data-theme="dark"] .nav-control-btn:hover {
    background: rgba(0,0,0,0.3);
    color: var(--text-inv);
}

[data-theme="dark"] .clear-search-btn {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
    color: var(--text-inv);
}

[data-theme="dark"] .clear-search-btn:hover {
    background: rgba(0,0,0,0.3);
}

[data-theme="dark"] .theme-toggle:hover {
    background: rgba(255,255,255,0.05);
}

[data-theme="dark"] .skeleton {
    background: linear-gradient(90deg, var(--border) 25%, var(--surface) 50%, var(--border) 75%);
}

[data-theme="dark"] .nav-empty {
    color: var(--text-inv2);
}

[data-theme="dark"] .nav-loading {
    color: var(--text-inv2);
}

[data-theme="dark"] .spinner {
    border-color: var(--border-dark);
}

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    color: var(--text-2);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    color: var(--text);
    background: rgba(0,0,0,0.05);
}

/* ─── Font Size Controls ─────────────────────────────────── */
.font-size-controls {
    display: flex;
    align-items: center;
    gap: 4px;
}

.font-size-btn {
    background: none;
    border: 1px solid var(--border);
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-2);
    transition: all var(--transition);
}

.font-size-btn:hover,
.font-size-btn.active {
    border-color: var(--accent);
    color: var(--accent);
}

[data-font-size="small"] .markdown-body { font-size: 0.9rem; }
[data-font-size="medium"] .markdown-body { font-size: 0.95rem; }
[data-font-size="large"] .markdown-body { font-size: 1.15rem; }

/* ─── Topbar Controls ───────────────────────────────────────── */
.topbar-controls {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-left: auto;
}

/* ─── Nav Controls (Expand/Collapse) ────────────────────────── */
.nav-controls {
    display: flex;
    gap: 8px;
    padding: 0 16px 12px;
    border-bottom: 1px solid var(--border);
}

.nav-control-btn {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-inv2);
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all var(--transition);
}

.nav-control-btn:hover {
    background: var(--surface);
    color: var(--text-inv);
    border-color: var(--accent);
}

/* ─── Search Highlight ─────────────────────────────────────── */
mark {
    background: rgba(200, 98, 42, 0.2);
    color: var(--accent);
    padding: 2px 4px;
    border-radius: 2px;
    font-weight: 500;
}

/* ─── Blog Posts ─────────────────────────────────────────────── */
.blog-posts {
    width: 100%;
    max-width: 800px;
    margin-top: 48px;
    text-align: left;
}

.blog-posts h3 {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-2);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.blog-skeleton {
    grid-column: 1 / -1;
    text-align: center;
    padding: 40px;
    color: var(--text-2);
    font-size: 1rem;
}

.blog-empty {
    grid-column: 1 / -1;
    text-align: center;
    padding: 32px;
    color: var(--text-2);
    font-size: 1rem;
    font-style: italic;
}

.blog-error {
    grid-column: 1 / -1;
    text-align: center;
    padding: 32px;
    color: #c0392b;
    font-size: 1rem;
}

.blog-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

.blog-cover {
    width: 100%;
    height: 140px;
    overflow: hidden;
}

.blog-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition);
}

.blog-card:hover .blog-cover img {
    transform: scale(1.05);
}

.blog-content {
    padding: 16px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.blog-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 10px;
}

.blog-tag {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-lt);
    padding: 2px 8px;
    border-radius: 4px;
}

.blog-title {
    font-family: var(--font-serif);
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--text);
    line-height: 1.4;
    margin-bottom: 8px;
}

.blog-excerpt {
    font-size: 0.9rem;
    color: var(--text-2);
    line-height: 1.5;
    margin-bottom: 12px;
    flex: 1;
}

.blog-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    font-size: 0.8rem;
    color: var(--text-2);
    margin-top: auto;
}

.blog-author {
    font-weight: 500;
    color: var(--text);
}

.blog-date::before,
.blog-read-time::before {
    content: "·";
    margin: 0 4px;
    color: var(--border);
}

/* ─── Blog Post View ──────────────────────────────────────────── */
.blog-post-view {
    max-width: 72ch;
    padding: 24px 0;
}

.blog-back-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: none;
    border: none;
    color: var(--text-2);
    font-size: 0.95rem;
    cursor: pointer;
    padding: 8px 12px;
    margin-bottom: 24px;
    border-radius: var(--radius);
    transition: all var(--transition);
}

.blog-back-btn:hover {
    color: var(--text);
    background: var(--accent-lt);
}

.blog-post-cover {
    width: 100%;
    max-height: 320px;
    overflow: hidden;
    border-radius: var(--radius);
    margin-bottom: 32px;
}

.blog-post-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.blog-post-header {
    margin-bottom: 32px;
}

.blog-post-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.blog-post-title {
    font-family: var(--font-serif);
    font-size: 2.2rem;
    font-weight: 500;
    color: var(--text);
    line-height: 1.2;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
}

.blog-post-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    font-size: 0.95rem;
    color: var(--text-2);
}

.blog-post-author {
    font-weight: 500;
    color: var(--text);
}

.blog-post-read-time::before {
    content: "·";
    margin: 0 4px;
}

.blog-post-content {
    font-size: 1.15rem;
    line-height: 1.8;
}

.blog-post-skeleton {
    padding: 32px 0;
}

/* ─── Dark Mode Blog Styles ─────────────────────────────────── */
[data-theme="dark"] .blog-card {
    background: var(--surface);
}

[data-theme="dark"] .blog-card:hover {
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

[data-theme="dark"] .blog-back-btn:hover {
    background: rgba(255,255,255,0.05);
}

[data-theme="dark"] .blog-tag {
    background: rgba(200, 98, 42, 0.15);
}

/* ─── Posts Page Styles ─────────────────────────────────────── */
.blog-posts-full {
    max-width: 100%;
    padding: 24px 0;
}

.blog-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.blog-search-wrap {
    position: relative;
    flex: 1;
    min-width: 200px;
    max-width: 400px;
}

.blog-search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-2);
    pointer-events: none;
}

#blogSearchInput {
    width: 100%;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 10px 14px 10px 38px;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text);
    outline: none;
    transition: border-color var(--transition), background var(--transition);
}

#blogSearchInput::placeholder {
    color: var(--text-2);
}

#blogSearchInput:focus {
    border-color: var(--accent);
    background: var(--surface);
}

.blog-filters {
    display: flex;
    gap: 8px;
}

.blog-filter-btn {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text-2);
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition);
}

.blog-filter-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.blog-filter-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: white;
}

.blog-grid-full {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.blog-load-more {
    text-align: center;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.blog-load-btn {
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 12px 32px;
    border-radius: var(--radius);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    cursor: pointer;
    transition: all var(--transition);
}

.blog-load-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--surface);
}

/* ─── Sidebar Nav Links ─────────────────────────────────────── */
.sidebar-nav-links {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
}

.sidebar-nav-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    color: var(--text-inv);
    text-decoration: none;
    font-size: 0.95rem;
    border-radius: var(--radius);
    transition: all var(--transition);
    margin-bottom: 4px;
}

.sidebar-nav-link:hover {
    background: var(--accent-lt);
    color: var(--accent);
}

.sidebar-nav-link.active {
    background: rgba(200, 98, 42, 0.1);
    color: var(--accent);
}

.sidebar-nav-link svg {
    flex-shrink: 0;
}

/* ─── Dark Mode Posts Page ──────────────────────────────────── */
[data-theme="dark"] #blogSearchInput {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
    color: var(--text);
}

[data-theme="dark"] #blogSearchInput:focus {
    background: rgba(0,0,0,0.3);
}

[data-theme="dark"] .blog-filter-btn {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
}

[data-theme="dark"] .blog-load-btn {
    background: rgba(0,0,0,0.2);
    border-color: var(--border-dark);
    color: var(--text);
}

[data-theme="dark"] .sidebar-nav-link:hover {
    background: rgba(255,255,255,0.05);
}

/* ─── Responsive ────────────────────────────────────────────── */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
    }
    .sidebar.open { transform: translateX(0); }
    .sidebar-overlay.visible { display: block; }
    .mobile-menu-btn { display: flex; }
    .content-area { padding: 24px 20px; }
    .topbar { padding: 0 16px; }
    .sidebar-toggle { display: none; }
}

@media (max-width: 480px) {
    .unit-header h1 { font-size: 1.6rem; }
    .content-area { padding: 20px 16px; }
}