/* ============================================
   Pickleball Bestie — Shared Stylesheet
   Warm & approachable design language
   ============================================ */

:root {
    /* Brand anchors */
    --paddle-black: #1a1a1a;
    --neon-yellow: #d4ff00;

    /* Softened supporting palette */
    --paddle-slate: #3d4852;
    --paddle-gray: #7b8794;
    --court-green: #00b894;
    --ball-yellow: #e8f442;
    --white: #ffffff;
    --off-white: #f5f5f0;
    --warm-gray: #edeee9;

    /* Header palette — warmer mid-tones instead of pure black */
    --header-dark: #2c3639;
    --header-mid: #3f4f54;

    /* Warm callout tones */
    --callout-insight-bg: #eef6fb;
    --callout-insight-border: #5ba4cf;
    --callout-insight-text: #1a3d5c;

    --callout-drill-bg: #edf9f0;
    --callout-drill-border: #4dbd74;
    --callout-drill-text: #1a4027;

    --callout-warning-bg: #fdf0ef;
    --callout-warning-border: #e06c60;
    --callout-warning-text: #6b2520;

    --callout-note-bg: #fef9ed;
    --callout-note-border: #e5b84c;
    --callout-note-text: #5c4813;

    /* Shadows & radii */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.08);
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
}

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

/* ---- Base ---- */
body {
    font-family: 'DM Sans', sans-serif;
    background: var(--off-white);
    color: var(--paddle-black);
    line-height: 1.75;
    overflow-x: hidden;
}

img, svg {
    max-width: 100%;
}

a {
    color: inherit;
}

/* ============================================
   Navigation
   ============================================ */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--header-dark);
    z-index: 1000;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
    border-radius: 0 0 12px 12px;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    height: 80px;
}

.logo {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 1.8rem;
    letter-spacing: 2px;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-ball {
    width: 28px;
    height: 28px;
    background: var(--neon-yellow);
    border-radius: 50%;
    box-shadow: 0 0 12px rgba(212, 255, 0, 0.4);
}

.nav-links {
    display: flex;
    gap: 36px;
    list-style: none;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
    transition: color 0.25s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--neon-yellow);
    border-radius: 1px;
    transition: width 0.25s ease;
}

.nav-links a:hover {
    color: var(--neon-yellow);
}

.nav-links a:hover::after {
    width: 100%;
}

/* Hamburger menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--white);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   Hero Section (index.html)
   ============================================ */
.hero {
    margin-top: 80px;
    background: linear-gradient(180deg, var(--header-dark) 0%, var(--header-mid) 60%, var(--off-white) 100%);
    padding: 120px 40px 140px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(212, 255, 0, 0.06), transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 4.5rem;
    color: var(--white);
    letter-spacing: 3px;
    line-height: 1.05;
    margin-bottom: 20px;
}

.hero .highlight {
    color: var(--neon-yellow);
}

.hero p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.85);
    max-width: 620px;
    margin-bottom: 36px;
    line-height: 1.8;
}

/* ---- CTA Buttons ---- */
.cta-buttons {
    display: flex;
    gap: 16px;
}

.btn {
    padding: 14px 32px;
    font-size: 0.95rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    border: none;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    transition: all 0.25s ease;
    border-radius: var(--radius-sm);
}

.btn-primary {
    background: var(--neon-yellow);
    color: var(--paddle-black);
    box-shadow: 0 2px 12px rgba(212, 255, 0, 0.2);
}

.btn-primary:hover {
    background: var(--ball-yellow);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(212, 255, 0, 0.35);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--paddle-black);
    border-color: var(--white);
    transform: translateY(-2px);
}

/* ============================================
   Page Headers (sub-pages)
   ============================================ */
.page-header {
    margin-top: 80px;
    background: linear-gradient(180deg, var(--header-dark) 0%, var(--header-mid) 55%, var(--off-white) 100%);
    padding: 80px 40px 100px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: -20%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(212, 255, 0, 0.06), transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.page-header h1 {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 4rem;
    color: var(--white);
    letter-spacing: 3px;
    margin-bottom: 12px;
    position: relative;
    z-index: 1;
}

.page-header p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 700px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
    line-height: 1.7;
}

/* ============================================
   Container
   ============================================ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 80px 40px;
}

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

.section-header h2 {
    font-family: 'DM Sans', sans-serif;
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--paddle-black);
    margin-bottom: 10px;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--paddle-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   Section Titles (fundamentals page)
   ============================================ */
.section {
    margin-bottom: 80px;
}

.section-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 2.8rem;
    letter-spacing: 2px;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 3px solid var(--neon-yellow);
    display: inline-block;
}

.section-intro {
    font-size: 1.1rem;
    color: var(--paddle-gray);
    margin-bottom: 40px;
    max-width: 800px;
    line-height: 1.8;
}

/* ============================================
   Quick Links Grid (homepage)
   ============================================ */
.quick-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 80px;
}

.quick-link-card {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: 36px;
    box-shadow: var(--shadow-md);
    transition: all 0.25s ease;
    border: 1px solid rgba(0, 0, 0, 0.04);
    position: relative;
    overflow: hidden;
}

.quick-link-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--neon-yellow), var(--court-green));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.quick-link-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.quick-link-card:hover::before {
    transform: scaleX(1);
}

.quick-link-card h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--paddle-black);
}

.quick-link-card p {
    color: var(--paddle-gray);
    margin-bottom: 20px;
    line-height: 1.7;
    font-size: 0.95rem;
}

.card-link {
    color: var(--paddle-black);
    font-weight: 600;
    text-decoration: none;
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: all 0.25s ease;
}

.card-link:hover {
    color: var(--court-green);
    gap: 10px;
}

/* ============================================
   Featured Content Grid (homepage)
   ============================================ */
.featured-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    margin-top: 48px;
}

.featured-card {
    background: var(--white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all 0.25s ease;
    border: 1px solid rgba(0, 0, 0, 0.04);
}

.featured-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.featured-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, var(--header-mid) 0%, var(--header-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.featured-image::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(212, 255, 0, 0.12), transparent);
    transform: translate(-50%, -50%);
}

.featured-content {
    padding: 28px;
}

.featured-content h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--paddle-black);
}

.featured-content p {
    color: var(--paddle-gray);
    margin-bottom: 20px;
    line-height: 1.7;
    font-size: 0.95rem;
}

/* ============================================
   Skill Cards (fundamentals)
   ============================================ */
.skill-grid {
    display: grid;
    gap: 32px;
}

.skill-card {
    background: var(--white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all 0.25s ease;
    border: 1px solid rgba(0, 0, 0, 0.04);
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.skill-header {
    background: linear-gradient(135deg, var(--header-mid) 0%, var(--header-dark) 100%);
    padding: 28px 36px;
    position: relative;
    overflow: hidden;
}

.skill-header::after {
    content: '';
    position: absolute;
    top: -30%;
    right: -5%;
    width: 180px;
    height: 180px;
    background: radial-gradient(circle, rgba(212, 255, 0, 0.06), transparent);
    border-radius: 50%;
}

.skill-number {
    display: inline-block;
    background: var(--neon-yellow);
    color: var(--paddle-black);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    text-align: center;
    line-height: 44px;
    font-family: 'DM Sans', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.skill-header h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 6px;
}

.skill-header p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 1rem;
}

.skill-body {
    padding: 36px;
}

/* ============================================
   Callout Boxes
   ============================================ */

/* Why Critical / Scientific Note */
.why-critical,
.scientific-note {
    background: var(--warm-gray);
    padding: 28px 28px 28px 32px;
    border-radius: var(--radius-md);
    margin-bottom: 28px;
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
}

.why-critical::before,
.scientific-note::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--callout-note-border);
    border-radius: 4px 0 0 4px;
}

.why-critical h4,
.scientific-note h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--callout-note-text);
    margin-bottom: 14px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    background: rgba(229, 184, 76, 0.2);
    display: inline-block;
    padding: 4px 12px;
    border-radius: 100px;
}

.why-critical p,
.scientific-note p {
    color: var(--paddle-slate);
    line-height: 1.75;
    font-size: 0.95rem;
}

/* Practice Drill */
.practice-drill {
    background: var(--white);
    padding: 28px 28px 28px 32px;
    border-radius: var(--radius-md);
    margin-top: 28px;
    border: 1px solid var(--warm-gray);
    position: relative;
    overflow: hidden;
}

.practice-drill::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--neon-yellow), var(--court-green));
    border-radius: 4px 0 0 4px;
}

.practice-drill h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--white);
    margin-bottom: 14px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    background: var(--court-green);
    display: inline-block;
    padding: 4px 12px;
    border-radius: 100px;
}

.practice-drill p {
    color: var(--paddle-slate);
    line-height: 1.75;
    font-size: 0.95rem;
}

/* Watch Out */
.watch-out {
    background: var(--white);
    border-radius: var(--radius-md);
    margin-top: 20px;
    border: 1px solid rgba(224, 108, 96, 0.25);
    position: relative;
    overflow: hidden;
}

.watch-out h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--callout-warning-text);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    background: #fdf0ef;
    display: block;
    padding: 14px 28px 14px 32px;
    margin: 0 0 0 0;
    border-bottom: 1px solid rgba(224, 108, 96, 0.15);
}

.watch-out ul {
    list-style: none;
    padding: 20px 28px 24px 32px;
    display: grid;
    gap: 8px;
}

.watch-out li {
    padding-left: 28px;
    position: relative;
    color: var(--paddle-slate);
    font-size: 0.93rem;
    line-height: 1.7;
}

.watch-out li::before {
    content: '';
    position: absolute;
    left: 4px;
    top: 10px;
    width: 10px;
    height: 10px;
    border: 2px solid var(--callout-warning-border);
    border-radius: 50%;
}

/* Key Insight */
.key-insight {
    background: var(--white);
    padding: 28px 28px 28px 32px;
    border-radius: var(--radius-md);
    border: 1px solid var(--warm-gray);
    margin: 28px 0;
    position: relative;
    overflow: hidden;
}

.key-insight::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--callout-insight-border), #8ec5e2);
    border-radius: 4px 0 0 4px;
}

.key-insight h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--callout-insight-text);
    margin-bottom: 14px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    background: rgba(91, 164, 207, 0.15);
    display: inline-block;
    padding: 4px 12px;
    border-radius: 100px;
}

.key-insight p {
    color: var(--paddle-slate);
    line-height: 1.75;
    font-size: 0.95rem;
}

/* ============================================
   Court Diagrams
   ============================================ */
.court-container {
    background: var(--warm-gray);
    padding: 28px;
    border-radius: var(--radius-sm);
    margin: 28px 0;
}

.court-svg {
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
    display: block;
}

/* ============================================
   Key Points List
   ============================================ */
.key-points {
    margin: 28px 0;
}

.key-points h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--paddle-black);
}

.key-points ul {
    list-style: none;
    display: grid;
    gap: 12px;
}

.key-points li {
    padding-left: 28px;
    position: relative;
    font-size: 0.95rem;
    line-height: 1.7;
}

.key-points li::before {
    content: '\2192';
    position: absolute;
    left: 0;
    color: var(--court-green);
    font-size: 1.2rem;
    font-weight: bold;
}

/* ============================================
   Physics Page — Sections
   ============================================ */
.physics-section {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: 44px;
    margin-bottom: 40px;
    box-shadow: var(--shadow-md);
    border-top: 3px solid var(--neon-yellow);
}

.physics-section h2 {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 2.6rem;
    letter-spacing: 2px;
    margin-bottom: 24px;
    color: var(--paddle-black);
}

.physics-section h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    margin: 36px 0 16px;
    color: var(--paddle-slate);
}

.intro-text {
    font-size: 1.1rem;
    color: var(--paddle-gray);
    margin-bottom: 32px;
    line-height: 1.8;
}

/* Diagram Container (physics page) */
.diagram-container {
    background: var(--warm-gray);
    padding: 36px;
    border-radius: var(--radius-sm);
    margin: 36px 0;
}

.diagram-title {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 24px;
    color: var(--paddle-slate);
}

.diagram-svg {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    display: block;
}

/* Formula Box */
.formula-box {
    background: var(--header-dark);
    color: var(--neon-yellow);
    padding: 28px;
    border-radius: var(--radius-sm);
    margin: 28px 0;
    font-family: 'JetBrains Mono', monospace;
}

.formula-box h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--white);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.formula {
    font-size: 1.2rem;
    text-align: center;
    padding: 16px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    margin: 12px 0;
}

.formula-explanation {
    font-family: 'DM Sans', sans-serif;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.75);
    margin-top: 12px;
    line-height: 1.7;
}

/* Comparison Grid */
.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin: 32px 0;
}

.comparison-card {
    background: var(--white);
    border-radius: var(--radius-sm);
    padding: 28px;
    box-shadow: var(--shadow-sm);
    border-top: 3px solid var(--neon-yellow);
}

.comparison-card h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--paddle-black);
}

.comparison-card ul {
    list-style: none;
    padding: 0;
}

.comparison-card li {
    padding: 10px 0 10px 28px;
    position: relative;
    border-bottom: 1px solid var(--warm-gray);
    font-size: 0.95rem;
}

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

.comparison-card li::before {
    content: '\2192';
    position: absolute;
    left: 0;
    color: var(--court-green);
    font-weight: bold;
    font-size: 1.1rem;
}

/* Practical Application */
.practical-app {
    background: linear-gradient(135deg, var(--header-mid) 0%, var(--header-dark) 100%);
    color: var(--white);
    padding: 36px;
    border-radius: var(--radius-sm);
    margin: 36px 0;
}

.practical-app h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--neon-yellow);
    margin-bottom: 16px;
}

.practical-app p {
    font-size: 1rem;
    line-height: 1.75;
    margin-bottom: 12px;
}

.practical-app ul {
    list-style: none;
    margin-top: 16px;
}

.practical-app li {
    padding: 8px 0 8px 28px;
    position: relative;
    font-size: 0.95rem;
}

.practical-app li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: var(--neon-yellow);
    font-weight: bold;
}

/* ============================================
   Paddle Guide — Coming Soon / Preview
   ============================================ */
.coming-soon {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: 64px 48px;
    text-align: center;
    box-shadow: var(--shadow-md);
    border-top: 3px solid var(--neon-yellow);
}

.coming-soon h2 {
    font-family: 'DM Sans', sans-serif;
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 24px;
    color: var(--paddle-black);
}

.coming-soon p {
    font-size: 1.1rem;
    color: var(--paddle-gray);
    max-width: 650px;
    margin: 0 auto 32px;
    line-height: 1.8;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.preview-card {
    background: var(--warm-gray);
    padding: 28px;
    border-radius: var(--radius-sm);
    text-align: left;
    transition: all 0.25s ease;
}

.preview-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.preview-card h3 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--paddle-slate);
}

.preview-card ul {
    list-style: none;
    padding: 0;
}

.preview-card li {
    padding: 6px 0 6px 24px;
    position: relative;
    color: var(--paddle-gray);
    font-size: 0.9rem;
}

.preview-card li::before {
    content: '\2192';
    position: absolute;
    left: 0;
    color: var(--court-green);
    font-weight: bold;
}

/* ============================================
   Footer
   ============================================ */
footer {
    background: var(--header-dark);
    color: var(--white);
    padding: 60px 40px 32px;
    margin-top: 80px;
    border-radius: 24px 24px 0 0;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 36px;
    margin-bottom: 36px;
}

.footer-section h4 {
    font-family: 'DM Sans', sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--neon-yellow);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.25s ease;
}

.footer-section a:hover {
    color: var(--neon-yellow);
}

.footer-bottom {
    text-align: center;
    padding-top: 28px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--paddle-gray);
    font-size: 0.85rem;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 20px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background: var(--header-dark);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        border-radius: 0 0 12px 12px;
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    }

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

    .nav-links li {
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }

    .nav-links a {
        display: block;
        padding: 14px 0;
    }

    .nav-links a::after {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .hero {
        padding: 80px 24px;
    }

    .hero h1 {
        font-size: 2.8rem;
    }

    .hero p {
        font-size: 1.05rem;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .page-header {
        padding: 60px 24px 80px;
    }

    .page-header h1 {
        font-size: 2.8rem;
    }

    .container {
        padding: 48px 20px;
    }

    .quick-links {
        grid-template-columns: 1fr;
    }

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

    .section-header h2 {
        font-size: 1.8rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .skill-body {
        padding: 24px;
    }

    .physics-section {
        padding: 28px 20px;
    }

    .physics-section h2 {
        font-size: 2rem;
    }

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

    .coming-soon {
        padding: 40px 24px;
    }

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