/* =========================================================
   C PROGRAMMING HUB - RESPONSIVE STYLES
   ========================================================= */

:root {
    --bg: #0b1220;
    --bg-soft: #101a2e;
    --surface: #172238;
    --surface-2: #1d2a40;
    --surface-3: #0f192b;
    --border: #2b3a52;
    --text: #e8eef8;
    --muted: #a9b6c9;
    --primary: #22c55e;
    --primary-dark: #16a34a;
    --accent: #38bdf8;
    --accent-soft: #0ea5e9;
    --warning: #f59e0b;
    --shadow: 0 18px 50px rgba(0, 0, 0, 0.22);
    --radius: 16px;
    --max-width: 1180px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 82px;
}

body {
    margin: 0;
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
        "Segoe UI", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.65;
}

a {
    color: inherit;
    text-decoration: none;
}

button,
input {
    font: inherit;
}

button {
    cursor: pointer;
}

.container {
    width: min(100% - 32px, var(--max-width));
    margin-inline: auto;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Navigation */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(11, 18, 32, 0.92);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(14px);
}

.nav-inner {
    width: min(100% - 32px, var(--max-width));
    min-height: 70px;
    margin-inline: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-code {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border: 1px solid #31516a;
    border-radius: 10px;
    color: var(--accent);
    background: var(--surface-3);
    font-weight: 800;
}

.brand strong,
.brand small {
    display: block;
}

.brand strong {
    font-size: 15px;
}

.brand small {
    color: var(--muted);
    font-size: 11px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-links a {
    color: var(--muted);
    padding: 9px 12px;
    border-radius: 9px;
    font-size: 14px;
    font-weight: 650;
}

.nav-links a:hover {
    color: var(--text);
    background: var(--surface);
}

.menu-toggle {
    display: none;
    background: transparent;
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 9px;
    padding: 7px 10px;
}

/* Hero */
.hero {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 15% 20%, rgba(56, 189, 248, 0.13), transparent 28%),
        radial-gradient(circle at 85% 10%, rgba(34, 197, 94, 0.10), transparent 25%),
        linear-gradient(135deg, #172238, #0f192b 65%, #101a2e);
    border-bottom: 1px solid var(--border);
}

.hero-content {
    width: min(100% - 32px, 900px);
    margin-inline: auto;
    text-align: center;
    padding: 88px 0 62px;
}

.eyebrow,
.section-label {
    color: var(--accent);
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.14em;
}

.hero h1 {
    max-width: 850px;
    margin: 14px auto 16px;
    font-size: clamp(2rem, 5vw, 3.8rem);
    line-height: 1.08;
    letter-spacing: -0.035em;
}

.hero-subtitle {
    max-width: 730px;
    margin: 0 auto;
    color: var(--muted);
    font-size: clamp(1rem, 2vw, 1.15rem);
}

.hero-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin: 30px 0 25px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 45px;
    padding: 10px 18px;
    border-radius: 10px;
    font-weight: 800;
    border: 1px solid transparent;
    transition: transform 0.2s ease, background 0.2s ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background: var(--primary);
    color: #06240f;
}

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

.btn-secondary {
    border-color: var(--border);
    background: rgba(255, 255, 255, 0.03);
    color: var(--text);
}

.search-wrap {
    position: relative;
    width: min(100%, 700px);
    margin: 0 auto;
}

.search-wrap input {
    width: 100%;
    height: 58px;
    padding: 0 50px;
    border: 1px solid #3a4b65;
    border-radius: 14px;
    background: #f8fafc;
    color: #0f172a;
    outline: none;
    box-shadow: var(--shadow);
}

.search-wrap input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.14);
}

.search-icon {
    position: absolute;
    left: 18px;
    top: 50%;
    transform: translateY(-52%);
    color: #64748b;
    font-size: 24px;
    z-index: 1;
}

.clear-search {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    display: none;
    width: 36px;
    height: 36px;
    border: 0;
    border-radius: 9px;
    background: #e2e8f0;
    color: #334155;
}

.clear-search.visible {
    display: block;
}

.search-help {
    color: var(--muted);
    font-size: 13px;
    margin: 10px 0 0;
}

.quick-search {
    color: var(--accent);
    border: 0;
    background: transparent;
    padding: 0 3px;
    font-weight: 700;
}

.quick-search:hover {
    text-decoration: underline;
}

/* Stats */
.stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
    margin-top: -25px;
    position: relative;
    z-index: 2;
}

.stat-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 18px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-card strong {
    display: block;
    color: var(--accent);
    font-size: 22px;
}

.stat-card span {
    color: var(--muted);
    font-size: 13px;
}

/* Sections */
.section {
    padding: 78px 0;
}

.section-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 30px;
    margin-bottom: 30px;
}

.section-heading h2 {
    margin: 7px 0 0;
    font-size: clamp(1.7rem, 3vw, 2.35rem);
    line-height: 1.15;
}

.section-heading > p {
    max-width: 440px;
    margin: 0;
    color: var(--muted);
}

/* Course cards */
.course-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.topic-card {
    display: flex;
    gap: 16px;
    padding: 22px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.topic-card:hover {
    transform: translateY(-3px);
    border-color: #41607d;
}

.topic-number {
    flex: 0 0 auto;
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: 12px;
    background: var(--surface-3);
    color: var(--accent);
    font-weight: 900;
}

.topic-card h3 {
    margin: 0 0 5px;
    font-size: 17px;
}

.topic-card p {
    margin: 0;
    color: var(--muted);
    font-size: 13px;
}

/* Programs */
.programs-section {
    background: #0d1627;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.category-heading {
    display: flex;
    align-items: center;
    gap: 16px;
    margin: 38px 0 18px;
}

.category-icon {
    display: grid;
    place-items: center;
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--accent);
    font-size: 13px;
    font-weight: 900;
}

.category-heading h2 {
    margin: 0;
    font-size: 21px;
}

.category-heading p {
    margin: 2px 0 0;
    color: var(--muted);
    font-size: 13px;
}

.program-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.program-card {
    min-width: 0;
    padding: 21px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.program-card:hover {
    transform: translateY(-2px);
    border-color: #3d5674;
}

.program-card.is-hidden {
    display: none;
}

.card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.lesson-badge {
    display: inline-flex;
    padding: 4px 9px;
    border-radius: 999px;
    font-size: 10px;
    font-weight: 900;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.lesson-badge.beginner {
    background: rgba(34, 197, 94, 0.13);
    color: #4ade80;
}

.lesson-badge.intermediate {
    background: rgba(245, 158, 11, 0.13);
    color: #fbbf24;
}

.lesson-badge.advanced {
    background: rgba(56, 189, 248, 0.13);
    color: #7dd3fc;
}

.lesson-number {
    color: #64748b;
    font-size: 12px;
    font-weight: 800;
}

.program-card h3 {
    margin: 13px 0 14px;
    font-size: 20px;
}

.notes {
    padding: 13px 15px;
    margin-bottom: 15px;
    background: #0a1220;
    border-left: 4px solid var(--accent);
    border-radius: 8px;
    color: #c8d4e5;
    font-size: 13px;
    line-height: 1.65;
}

.notes p {
    margin: 0 0 7px;
}

.notes p:last-child {
    margin-bottom: 0;
}

.notes b {
    color: var(--accent);
}

.notes code {
    color: #7dd3fc;
}

pre {
    position: relative;
    margin: 0 0 13px;
    padding: 18px;
    overflow-x: auto;
    border: 1px solid #101b30;
    border-radius: 10px;
    background: #020617;
    color: #b9e9ff;
    font-family: "Cascadia Code", "Fira Code", Consolas, monospace;
    font-size: 13px;
    line-height: 1.55;
    tab-size: 4;
}

code {
    font-family: "Cascadia Code", "Fira Code", Consolas, monospace;
}

.copy-btn {
    border: 0;
    border-radius: 8px;
    padding: 9px 14px;
    background: var(--primary);
    color: #06240f;
    font-weight: 850;
    transition: transform 0.15s ease, background 0.15s ease;
}

.copy-btn:hover {
    background: var(--primary-dark);
    color: white;
    transform: translateY(-1px);
}

.copy-btn.copied {
    background: #38bdf8;
    color: #062033;
}

.no-results {
    text-align: center;
    padding: 50px 20px;
    border: 1px dashed var(--border);
    border-radius: var(--radius);
    background: var(--surface);
}

.no-results > div {
    font-size: 34px;
}

.no-results h3 {
    margin: 8px 0 3px;
}

.no-results p {
    margin: 0;
    color: var(--muted);
}

/* Projects */
.projects {
    background: var(--bg);
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.project-card {
    padding: 22px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.project-card > span {
    color: var(--accent);
    font-weight: 900;
    font-size: 12px;
}

.project-card h3 {
    margin: 10px 0 6px;
}

.project-card p {
    margin: 0 0 14px;
    color: var(--muted);
    font-size: 13px;
}

.project-card a {
    color: var(--accent);
    font-size: 13px;
    font-weight: 750;
}

/* Practice */
.practice {
    padding-top: 20px;
}

.practice-box {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 35px;
    padding: 34px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: linear-gradient(135deg, var(--surface), var(--surface-3));
}

.practice-box h2 {
    margin: 8px 0;
    font-size: 28px;
}

.practice-box p {
    color: var(--muted);
    max-width: 650px;
}

.practice-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    align-content: center;
}

.practice-list div {
    padding: 11px 13px;
    border-radius: 9px;
    background: rgba(56, 189, 248, 0.07);
    border: 1px solid rgba(56, 189, 248, 0.12);
    color: #dbeafe;
    font-size: 13px;
}

/* CTA */
.cta-section {
    padding: 75px 0;
    background:
        radial-gradient(circle at 50% 0%, rgba(56, 189, 248, 0.14), transparent 35%),
        #0d1627;
    border-top: 1px solid var(--border);
}

.cta {
    text-align: center;
}

.cta h2 {
    margin: 10px 0;
    font-size: clamp(1.8rem, 4vw, 2.8rem);
}

.cta p {
    max-width: 650px;
    margin: 0 auto 24px;
    color: var(--muted);
}

/* Footer */
footer {
    border-top: 1px solid var(--border);
    background: #080f1b;
}

.footer-inner {
    padding: 35px 0;
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 25px;
    align-items: center;
}

.footer-inner strong {
    font-size: 16px;
}

.footer-inner p {
    margin: 5px 0 0;
    color: var(--muted);
    font-size: 13px;
}

.footer-links {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--muted);
    font-size: 13px;
}

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

.copyright {
    grid-column: 1 / -1;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}

/* Search highlighting */
.search-match {
    outline: 2px solid rgba(56, 189, 248, 0.32);
}

/* Responsive */
@media (max-width: 900px) {
    .course-grid,
    .project-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .practice-box {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 720px) {
    .nav-inner {
        min-height: 62px;
    }

    .menu-toggle {
        display: block;
    }

    .nav-links {
        position: absolute;
        left: 16px;
        right: 16px;
        top: 68px;
        display: none;
        flex-direction: column;
        align-items: stretch;
        padding: 8px;
        background: #101a2e;
        border: 1px solid var(--border);
        border-radius: 12px;
        box-shadow: var(--shadow);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links a {
        padding: 12px;
    }

    .hero-content {
        padding: 62px 0 50px;
    }

    .stats {
        grid-template-columns: 1fr 1fr;
        margin-top: -18px;
    }

    .section {
        padding: 58px 0;
    }

    .section-heading {
        display: block;
    }

    .section-heading > p {
        margin-top: 10px;
    }

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

    .footer-inner {
        grid-template-columns: 1fr;
    }

    .footer-links {
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .container,
    .nav-inner {
        width: min(100% - 22px, var(--max-width));
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-actions .btn {
        width: 100%;
    }

    .stats {
        gap: 8px;
    }

    .stat-card {
        padding: 13px 8px;
    }

    .stat-card strong {
        font-size: 18px;
    }

    .program-card,
    .practice-box {
        padding: 16px;
    }

    pre {
        padding: 14px;
        font-size: 12px;
    }

    .practice-list {
        grid-template-columns: 1fr;
    }
}
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo img {
    width: 50px;
    height: 50px;
    object-fit: contain;
    border-radius: 10px;
}

.logo span {
    font-size: 1.25rem;
    font-weight: 800;
}
/* Respect reduced motion preferences */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition: none !important;
    }
}

/* Expanded hub additions */
.site-footer { margin-top: 4rem; padding: 3rem 1rem; }
.site-footer a { text-decoration: underline; }
details { margin: 1rem 0; padding: 1rem 1.2rem; border: 1px solid rgba(127,127,127,.25); border-radius: 12px; }
details summary { cursor: pointer; font-weight: 700; }
.course-intro ul, .course-intro ol { padding-left: 1.4rem; }
.course-intro li { margin: .7rem 0; }