/* ═══════════════════════════════════════════════════════════════
   NULLSECTOR V2 — COMPONENT LIBRARY
   Reusable UI components for all pages
   ═══════════════════════════════════════════════════════════════ */

/* ── Navigation ─────────────────────────────────────────────── */
.ns-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    display: flex;
    align-items: center;
    padding: 0 var(--space-xl);
    transition: all var(--duration-normal) var(--ease-out);
}

.ns-nav.scrolled {
    background: rgba(0, 0, 0, 0.95);
    border-bottom-color: var(--border-light);
}

.ns-nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
}

.ns-nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
    transition: opacity var(--duration-fast);
}
.ns-nav-brand:hover { opacity: 0.8; }
.ns-nav-brand img { width: 36px; height: 36px; }

/* Global Icon Styling */
.ns-icon {
    width: 1em;
    height: 1em;
    stroke-width: 2;
    display: inline-block;
    vertical-align: middle;
}

.ns-nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.ns-nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.5rem 0.85rem;
    border-radius: var(--radius-md);
    transition: all var(--duration-fast);
    white-space: nowrap;
}
.ns-nav-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}
.ns-nav-link.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.08);
}
.ns-nav-link.accent {
    background: var(--gradient-brand);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* Dropdown */
.ns-dropdown { position: relative; }
.ns-dropdown-trigger {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.5rem 0.85rem;
    border-radius: var(--radius-md);
    transition: all var(--duration-fast);
}
.ns-dropdown-trigger:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}
.ns-dropdown-arrow {
    font-size: 0.6rem;
    transition: transform var(--duration-normal) var(--ease-out);
}
.ns-dropdown:hover .ns-dropdown-arrow { transform: rotate(180deg); }
.ns-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-elevated);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding-top: 8px;
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--duration-normal) var(--ease-out), visibility var(--duration-normal);
    box-shadow: var(--shadow-lg);
}
.ns-dropdown-menu-inner {
    background: var(--bg-elevated);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 0.5rem;
    overflow: hidden;
}
.ns-dropdown:hover .ns-dropdown-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}
.ns-dropdown-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--duration-fast);
    font-size: 0.9rem;
}
.ns-dropdown-item:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

/* Mobile menu */
.ns-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast);
}
.ns-menu-btn:hover { background: rgba(255, 255, 255, 0.05); }

.ns-mobile-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-normal);
}
.ns-mobile-overlay.open { opacity: 1; visibility: visible; }

.ns-mobile-drawer {
    position: fixed;
    top: 0;
    right: 0;
    width: 300px;
    height: 100vh;
    background: var(--bg-surface);
    border-left: 1px solid var(--border);
    z-index: 1001;
    padding: var(--space-xl);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    transform: translateX(100%);
    transition: transform var(--duration-normal) var(--ease-out);
    overflow-y: auto;
}
.ns-mobile-drawer.open { transform: translateX(0); }

.ns-mobile-link {
    display: block;
    padding: 0.85rem 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 1rem;
    border-radius: var(--radius-md);
    transition: all var(--duration-fast);
}
.ns-mobile-link:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

@media (max-width: 1024px) {
    .ns-nav-links { display: none; }
    .ns-menu-btn { display: flex; }
}

/* ── Buttons ────────────────────────────────────────────────── */
.ns-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.8rem 1.75rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.95rem;
    border: none;
    transition: all var(--duration-normal) var(--ease-out);
    white-space: nowrap;
    text-decoration: none;
}

.ns-btn-primary {
    background: var(--text-primary);
    color: var(--bg-root);
}
.ns-btn-primary:hover {
    background: #e0e0e0;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.15);
}

.ns-btn-ghost {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}
.ns-btn-ghost:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.ns-btn-gradient {
    background: var(--gradient-brand);
    color: #fff;
    background-size: 200% 200%;
    animation: gradientShift 3s ease infinite;
}
.ns-btn-gradient:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 229, 255, 0.2);
}

.ns-btn-lg {
    padding: 1rem 2.25rem;
    font-size: 1.05rem;
    border-radius: var(--radius-lg);
}

.ns-btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

.ns-btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: var(--radius-md);
}

/* ── Cards ──────────────────────────────────────────────────── */
.ns-card {
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    transition: all var(--duration-normal) var(--ease-out);
    position: relative;
    overflow: hidden;
}

.ns-card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: var(--gradient-subtle);
    opacity: 0;
    transition: opacity var(--duration-normal);
    pointer-events: none;
}

.ns-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}
.ns-card:hover::before { opacity: 1; }

.ns-card-sm { padding: var(--space-lg); border-radius: var(--radius-lg); }
.ns-card-interactive { cursor: pointer; }

/* Card with glow effect on hover */
.ns-card-glow:hover {
    box-shadow: var(--shadow-glow-cyan);
}

/* ── Badges ─────────────────────────────────────────────────── */
.ns-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.35rem 0.85rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    white-space: nowrap;
}

.ns-badge-outline {
    background: transparent;
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
}

.ns-badge-cyan { background: rgba(0, 229, 255, 0.12); color: var(--accent-cyan); }
.ns-badge-magenta { background: rgba(255, 0, 85, 0.12); color: var(--accent-magenta); }
.ns-badge-purple { background: rgba(124, 58, 237, 0.12); color: var(--accent-purple); }
.ns-badge-green { background: rgba(34, 197, 94, 0.12); color: var(--accent-green); }
.ns-badge-amber { background: rgba(245, 158, 11, 0.12); color: var(--accent-amber); }
.ns-badge-blue { background: rgba(59, 130, 246, 0.12); color: var(--accent-blue); }
.ns-badge-white { background: rgba(255, 255, 255, 0.1); color: var(--text-primary); }

/* ── Accordion ──────────────────────────────────────────────── */
.ns-accordion-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: border-color var(--duration-normal);
    margin-bottom: var(--space-sm);
}
.ns-accordion-item:hover { border-color: var(--border-light); }
.ns-accordion-item.active { border-color: var(--border-hover); }

.ns-accordion-trigger {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    width: 100%;
    padding: var(--space-lg) var(--space-xl);
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
    transition: background var(--duration-fast);
}
.ns-accordion-trigger:hover { background: rgba(255, 255, 255, 0.02); }

.ns-accordion-icon {
    width: 2rem;
    height: 2rem;
    background: var(--text-primary);
    color: var(--bg-root);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.ns-accordion-title { flex: 1; }

.ns-accordion-chevron {
    font-size: 1.25rem;
    color: var(--text-muted);
    transition: transform var(--duration-normal) var(--ease-out);
    flex-shrink: 0;
}
.ns-accordion-item.active .ns-accordion-chevron { transform: rotate(45deg); }

.ns-accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--duration-normal) var(--ease-out);
}
.ns-accordion-item.active .ns-accordion-content { max-height: 2000px; }

.ns-accordion-body {
    padding: 0 var(--space-xl) var(--space-xl) calc(2rem + var(--space-md) + var(--space-xl));
    color: var(--text-secondary);
    line-height: 1.8;
}
.ns-accordion-body ul, .ns-accordion-body ol {
    margin: 0.75rem 0;
    padding-left: 1.25rem;
    list-style: disc;
}
.ns-accordion-body li { margin-bottom: 0.4rem; }
.ns-accordion-body strong { color: var(--text-primary); }
.ns-accordion-body code {
    background: var(--bg-elevated);
    color: var(--accent-cyan);
    padding: 0.15rem 0.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.85em;
}
.ns-accordion-body a {
    color: var(--accent-cyan);
    transition: opacity var(--duration-fast);
}
.ns-accordion-body a:hover { opacity: 0.8; text-decoration: underline; }

/* ── Grid ───────────────────────────────────────────────────── */
.ns-grid {
    display: grid;
    gap: var(--space-xl);
}
.ns-grid-2 { grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); }
.ns-grid-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.ns-grid-4 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

@media (max-width: 768px) {
    .ns-grid-2, .ns-grid-3, .ns-grid-4 {
        grid-template-columns: 1fr;
    }
}

/* ── Section Divider ────────────────────────────────────────── */
.ns-divider {
    border: none;
    height: 1px;
    background: var(--border);
    margin: var(--space-3xl) 0;
}

/* ── Hero Section ───────────────────────────────────────────── */
.ns-hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: calc(var(--nav-height) + var(--space-4xl)) var(--space-xl) var(--space-4xl);
    position: relative;
    overflow: hidden;
}

.ns-hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: hidden;
}

.ns-hero-bg .orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.4;
    animation: float 20s ease-in-out infinite;
}

.ns-hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
}

/* ── Footer ─────────────────────────────────────────────────── */
.ns-footer {
    border-top: 1px solid var(--border);
    padding: var(--space-3xl) 0 var(--space-xl);
    color: var(--text-muted);
    font-size: 0.875rem;
}

.ns-footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-md);
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-xl);
}

.ns-footer-links {
    display: flex;
    gap: var(--space-lg);
}

.ns-footer-link {
    color: var(--text-muted);
    transition: color var(--duration-fast);
}
.ns-footer-link:hover { color: var(--text-primary); }

@media (max-width: 640px) {
    .ns-footer-inner { flex-direction: column; text-align: center; }
}

/* ── Stat Card ──────────────────────────────────────────────── */
.ns-stat {
    text-align: center;
    padding: var(--space-xl);
}
.ns-stat-value {
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 900;
    line-height: 1;
    margin-bottom: 0.25rem;
}
.ns-stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ── Progress Bar ───────────────────────────────────────────── */
.ns-progress {
    width: 100%;
    height: 6px;
    background: var(--border);
    border-radius: var(--radius-full);
    overflow: hidden;
}
.ns-progress-bar {
    height: 100%;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: width 0.8s var(--ease-out);
}

/* ── Chapter Item (for roadmap/dashboard lists) ─────────────── */
.ns-chapter-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all var(--duration-normal) var(--ease-out);
    text-decoration: none;
    color: inherit;
}
.ns-chapter-item:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    transform: translateX(4px);
}
.ns-chapter-item.completed {
    border-color: rgba(34, 197, 94, 0.3);
}

.ns-chapter-num {
    width: 2.25rem;
    height: 2.25rem;
    border-radius: var(--radius-full);
    background: var(--border-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.8rem;
    color: var(--text-secondary);
    flex-shrink: 0;
    transition: all var(--duration-normal);
}
.ns-chapter-item.completed .ns-chapter-num {
    background: var(--accent-green);
    color: #000;
}

.ns-chapter-info { flex: 1; min-width: 0; }
.ns-chapter-title {
    font-weight: 600;
    font-size: 0.95rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.ns-chapter-meta {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.ns-chapter-arrow {
    color: var(--text-dim);
    font-size: 1.1rem;
    flex-shrink: 0;
    transition: all var(--duration-normal);
}
.ns-chapter-item:hover .ns-chapter-arrow {
    color: var(--text-secondary);
    transform: translateX(4px);
}

/* ── Code Block ─────────────────────────────────────────────── */
.ns-code {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

/* ── Resource Link Card ─────────────────────────────────────── */
.ns-resource {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all var(--duration-normal) var(--ease-out);
    text-decoration: none;
    color: inherit;
}
.ns-resource:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.ns-resource-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.ns-resource-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
}
.ns-resource-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.5;
}
.ns-resource-tag {
    display: inline-block;
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    padding: 0.2rem 0.6rem;
    background: rgba(255, 255, 255, 0.04);
    border-radius: var(--radius-full);
}

/* ── Tip/Info Box ───────────────────────────────────────────── */
.ns-callout {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg) var(--space-xl);
    margin: var(--space-xl) 0;
    display: flex;
    gap: var(--space-md);
}
.ns-callout-icon { font-size: 1.25rem; flex-shrink: 0; padding-top: 0.1rem; }
.ns-callout-content { flex: 1; color: var(--text-secondary); line-height: 1.7; }
.ns-callout-content strong { color: var(--text-primary); }

.ns-callout-tip { border-left: 3px solid var(--accent-cyan); }
.ns-callout-warn { border-left: 3px solid var(--accent-amber); }
.ns-callout-info { border-left: 3px solid var(--accent-purple); }

/* ── Page Header ────────────────────────────────────────────── */
.ns-page-header {
    padding: calc(var(--nav-height) + var(--space-4xl)) 0 var(--space-3xl);
    text-align: center;
}
.ns-page-header .breadcrumb {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}
.ns-page-header .breadcrumb a {
    color: var(--accent-cyan);
    transition: opacity var(--duration-fast);
}
.ns-page-header .breadcrumb a:hover { opacity: 0.7; }

/* ── Complete Button ────────────────────────────────────────── */
.ns-complete-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem 2rem;
    background: var(--text-primary);
    color: var(--bg-root);
    border: none;
    border-radius: var(--radius-md);
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--duration-normal) var(--ease-out);
}
.ns-complete-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(255, 255, 255, 0.15);
}
.ns-complete-btn.done {
    background: var(--accent-green);
    color: #000;
    cursor: default;
    transform: none;
    box-shadow: none;
}

/* ── Loading Spinner ────────────────────────────────────────── */
.ns-spinner {
    width: 24px;
    height: 24px;
    border: 2px solid var(--border);
    border-top-color: var(--text-primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Full Page Loader ───────────────────────────────────────── */
.ns-loader {
    position: fixed;
    inset: 0;
    background: var(--bg-root);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--duration-slow);
}
.ns-loader.hide {
    opacity: 0;
    pointer-events: none;
}

/* ═══════════════════════════════════════════════════════════════
   MOBILE RESPONSIVE — All breakpoints
   These rules ONLY activate on small screens.
   Desktop layout is completely unaffected.
   ═══════════════════════════════════════════════════════════════ */

/* ── 1024px — Tablet ──────────────────────────────────────────── */
@media (max-width: 1024px) {
    :root { --space-4xl: 3rem; }

    .ns-hero {
        padding: calc(var(--nav-height) + 3rem) var(--space-lg) 3rem;
    }

    .ns-page-header {
        padding: calc(var(--nav-height) + 2.5rem) 0 2rem;
    }

    /* Chapter pages */
    .ch { padding: calc(var(--nav-height) + 1.5rem) 1.5rem 3rem; }

    /* Walkthrough pages */
    .content-page { padding: 1.5rem; }

    /* Dashboard grid */
    .ns-grid-4 { grid-template-columns: repeat(2, 1fr); }
}

/* ── 768px — Mobile landscape / small tablet ─────────────────── */
@media (max-width: 768px) {
    :root {
        --space-3xl: 2rem;
        --space-4xl: 2.5rem;
        --nav-height: 64px;
    }

    /* Nav: hide desktop links, show hamburger */
    .ns-nav-links { display: none !important; }
    .ns-menu-btn { display: flex !important; }

    /* Hero */
    .ns-hero {
        padding: calc(var(--nav-height) + 2rem) var(--space-md) 2.5rem;
        text-align: center;
    }
    .ns-hero h1 { font-size: clamp(2rem, 8vw, 3rem); }
    .ns-hero p { font-size: 1rem; }

    /* Buttons — make them full-width on mobile */
    .ns-hero .ns-btn + .ns-btn { margin-top: 0.75rem; }
    .ns-hero-ctas {
        flex-direction: column;
        align-items: stretch;
        width: 100%;
        max-width: 320px;
        margin: 0 auto;
    }
    .ns-hero-ctas .ns-btn { width: 100%; justify-content: center; }

    /* Chapter pages */
    .ch { padding: calc(var(--nav-height) + 1rem) 1rem 2.5rem; }
    .ch-head h1 { font-size: clamp(1.6rem, 6vw, 2.5rem); }
    .ch-nav { flex-direction: column; gap: 0.75rem; }
    .ch-nav .ns-btn { width: 100%; text-align: center; justify-content: center; }

    /* Walkthrough pages */
    .content-page { padding: 1rem; max-width: 100%; }
    .section { padding: 1.25rem; }
    .grid { grid-template-columns: 1fr !important; }
    .challenge-card { padding: 1.25rem; }
    .challenge-header { flex-direction: column; gap: 0.5rem; }

    /* Roadmap pages */
    .ns-chapter-item { padding: 0.85rem 1rem; }
    .ns-chapter-title { font-size: 0.9rem; }

    /* Dashboard */
    .ns-grid-2, .ns-grid-3, .ns-grid-4 { grid-template-columns: 1fr; }
    .ns-stat { padding: 1rem; }
    .ns-stat-value { font-size: 2rem; }

    /* Cards */
    .ns-card { padding: 1.25rem; }

    /* Footer */
    .ns-footer-inner { flex-direction: column; text-align: center; gap: 1rem; }
    .ns-footer-links { flex-wrap: wrap; justify-content: center; gap: 1rem; }

    /* Resources page */
    .ns-resource { flex-direction: column; gap: 0.75rem; }
    .ns-resource-icon { width: 2rem; height: 2rem; font-size: 1.25rem; }

    /* FAQ page */
    .faq-answer { font-size: 0.9rem; }

    /* Null Labs */
    .ns-page-header { padding: calc(var(--nav-height) + 1.5rem) 1rem 1.5rem; }
    .container, .ns-container { padding-left: 1rem; padding-right: 1rem; }
}

/* ── 480px — Mobile portrait ─────────────────────────────────── */
@media (max-width: 480px) {
    :root {
        --space-xl: 1rem;
        --space-2xl: 1.5rem;
    }

    /* Nav brand — shrink text */
    .ns-nav-brand span { font-size: 1.1rem; }
    .ns-nav-brand img { width: 28px; height: 28px; }
    .ns-nav { padding: 0 1rem; }

    /* Hero */
    .ns-hero h1 { font-size: clamp(1.75rem, 9vw, 2.5rem); }

    /* Chapter */
    .ch { padding: calc(var(--nav-height) + 0.75rem) 0.875rem 2rem; }
    .ch-head { margin-bottom: 1.5rem; }
    .ch-sec { margin-bottom: 2rem; }
    .ch-sec-h h2 { font-size: 1.15rem; }
    .rc { padding: 1rem; }
    .qc { padding: 1rem; }
    .ti { padding: 0.875rem; }

    /* Walkthrough */
    .section pre { font-size: 0.78rem; padding: 0.875rem; overflow-x: auto; }
    .section code { font-size: 0.78rem; }
    .back-link { padding: 0.4rem 0.75rem; font-size: 0.85rem; }

    /* Badges */
    .badge { font-size: 0.7rem; }

    /* Buttons */
    .ns-btn { padding: 0.75rem 1.5rem; font-size: 0.9rem; }
    .ns-btn-lg { padding: 0.875rem 1.75rem; font-size: 0.95rem; }

    /* Cards */
    .ns-card { padding: 1rem; border-radius: var(--radius-md); }

    /* Chapter nav buttons */
    .ch-nav .ns-btn { padding: 0.75rem 1rem; font-size: 0.9rem; }

    /* Resource cards in chapters */
    .rc h3 { font-size: 0.92rem; }
    .rc p { font-size: 0.82rem; }

    /* Mobile drawer */
    .ns-mobile-drawer { width: 100%; max-width: 100%; }

    /* Walkthrough section headings */
    .section h2 { font-size: 1.15rem; }
    .section h3 { font-size: 1rem; }

    /* Info/warning boxes */
    .info-box, .warning-box, .success-box, .danger-box {
        padding: 1rem;
    }

    /* Footer */
    .ns-footer { padding: 1.5rem 0 1rem; }
}

/* ── Touch device improvements ───────────────────────────────── */
@media (hover: none) and (pointer: coarse) {
    /* Larger touch targets */
    .ns-nav-link, .ns-mobile-link { min-height: 44px; display: flex; align-items: center; }
    .ns-btn { min-height: 44px; }
    .oauth-btn { min-height: 52px; }
    .rc { cursor: default; }
    .rc:hover { transform: none; }
    .ns-chapter-item:hover { transform: none; }
    .ns-resource:hover { transform: none; }
    .back-link:hover { transform: none; }

    /* Prevent hover effects that don't work on touch */
    .ns-card:hover { transform: none; }
    .ns-dropdown-menu { display: none !important; } /* Use mobile drawer instead */
}

/* ── Landscape phone fix ─────────────────────────────────────── */
@media (max-width: 768px) and (orientation: landscape) {
    .ns-hero {
        min-height: auto;
        padding: calc(var(--nav-height) + 1.5rem) var(--space-md) 2rem;
    }
    .ns-mobile-drawer { overflow-y: auto; }
}

/* ── Accessible: Reduce Motion ───────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .ns-hero-bg .orb { animation: none; }
}