/* ==========================================================================
   Hendrik Grobbelaar - Modern Developer Portfolio Design System
   Pure CSS System - Compatible with GitHub Pages & Static Hosting
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@400;500;600;700;800&family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Fira+Code:wght@400;500&display=swap');

/* --- 1. CSS Custom Properties & Design Tokens --- */
:root {
    /* Light Theme Palette - Sage Green */
    --bg-main: #f7f9f7;
    --bg-card: #ffffff;
    --bg-card-hover: #f0f4f1;
    --bg-panel: #f0f4f1;
    --border-color: #e0e7e1;
    --border-accent: rgba(91, 130, 102, 0.35);
    
    --text-primary: #121f16;
    --text-secondary: #2c3e32;
    --text-muted: #58695d;
    
    --accent-primary: #4e785e;
    --accent-secondary: #33543f;
    --accent-teal: #3b8271;
    --accent-gradient: linear-gradient(135deg, #5b8266 0%, #33543f 100%);
    --accent-glow: rgba(91, 130, 102, 0.2);
    
    --header-bg: rgba(255, 255, 255, 0.88);
    --shadow-sm: 0 2px 8px rgba(18, 31, 22, 0.05);
    --shadow-md: 0 10px 25px -5px rgba(18, 31, 22, 0.08);
    --shadow-lg: 0 20px 40px -15px rgba(18, 31, 22, 0.12);
    --shadow-glow: 0 0 25px rgba(91, 130, 102, 0.2);

    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Plus Jakarta Sans', sans-serif;
    --font-code: 'Fira Code', monospace;

    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Dark Theme Palette Override - Deep Sage & Forest Obsidian */
body.dark {
    --bg-main: #0c120e;
    --bg-card: #141f17;
    --bg-card-hover: #1c2b20;
    --bg-panel: #111a13;
    --border-color: rgba(255, 255, 255, 0.08);
    --border-accent: rgba(132, 173, 146, 0.35);

    --text-primary: #f2f7f3;
    --text-secondary: #c9d8cd;
    --text-muted: #8ea093;

    --accent-primary: #84ad92;
    --accent-secondary: #a3c9ae;
    --accent-teal: #6bbfa8;
    --accent-gradient: linear-gradient(135deg, #84ad92 0%, #4b7359 100%);
    --accent-glow: rgba(132, 173, 146, 0.25);

    --header-bg: rgba(12, 18, 14, 0.88);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 12px 30px -5px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 30px rgba(132, 173, 146, 0.25);
}

/* --- 2. Base Styles & Resets --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--accent-secondary);
}

/* --- 3. Fixed Modern Glass Header --- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: var(--header-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    transition: all var(--transition-smooth);
}

.header-container {
    max-width: 1280px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none !important;
}

.brand-badge {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    background: var(--accent-gradient);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    font-weight: 800;
    box-shadow: 0 4px 12px rgba(78, 120, 94, 0.35);
}

/* Nav Menu Items */
.main-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-pills-modern {
    display: flex;
    list-style: none;
    gap: 0.5rem;
    background: var(--bg-panel);
    padding: 0.35rem;
    border-radius: var(--radius-full);
    border: 1px solid var(--border-color);
}

.nav-pills-modern .nav-item {
    margin: 0;
}

.nav-pills-modern .nav-link-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1.25rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.nav-pills-modern .nav-link-item img.nav-icon {
    width: 18px;
    height: 18px;
    object-fit: contain;
    transition: transform var(--transition-fast);
}

.nav-pills-modern .nav-link-item:hover {
    color: var(--text-primary);
    background: var(--bg-card);
}

.nav-pills-modern .nav-link-item.active {
    background: var(--accent-gradient);
    color: #ffffff !important;
    box-shadow: 0 4px 15px rgba(2, 132, 199, 0.3);
}

.nav-pills-modern .nav-link-item.active img.nav-icon {
    filter: brightness(0) invert(1);
}

/* Header Controls & Theme Button */
.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-switch-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.8rem;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-switch-btn:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-sm);
}

.modeButton {
    position: relative;
    width: 44px;
    height: 24px;
    background: var(--border-color);
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: background 0.3s;
}

.movingdot {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: #ffffff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0;
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

body.dark .movingdot {
    transform: translateX(20px);
    background: var(--accent-primary);
}

.theme-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Mobile Navigation Drawer */
.mobile-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    flex-direction: column;
    gap: 5px;
}

.mobile-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s;
}

/* --- 4. Hero Section --- */
.hero-section {
    padding-top: 140px;
    padding-bottom: 80px;
    min-height: 85vh;
    display: flex;
    align-items: center;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 4rem;
    align-items: center;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    background: rgba(13, 148, 136, 0.1);
    border: 1px solid rgba(13, 148, 136, 0.3);
    color: var(--accent-teal);
    font-size: 0.85rem;
    font-weight: 700;
    border-radius: var(--radius-full);
    margin-bottom: 1.5rem;
}

.status-pulse {
    width: 8px;
    height: 8px;
    background: var(--accent-teal);
    border-radius: 50%;
    box-shadow: 0 0 0 0 rgba(13, 148, 136, 0.7);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(13, 148, 136, 0.7);
    }
    70% {
        box-shadow: 0 0 0 10px rgba(13, 148, 136, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(13, 148, 136, 0);
    }
}

.hero-title {
    font-size: 3.25rem;
    line-height: 1.15;
    margin-bottom: 1rem;
}

.hero-title .gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle-container {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    height: 2.2rem;
    display: flex;
    align-items: center;
}

.typewriter-cursor {
    color: var(--accent-primary);
    animation: blink 0.8s infinite;
    font-weight: 300;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.hero-bio {
    font-size: 1.1rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
    max-width: 600px;
    line-height: 1.7;
}

.hero-ctas {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.btn-primary-custom {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.85rem 1.75rem;
    background: var(--accent-gradient);
    color: #ffffff !important;
    font-weight: 700;
    font-size: 1rem;
    border-radius: var(--radius-md);
    box-shadow: 0 8px 20px rgba(78, 120, 94, 0.3);
    transition: all var(--transition-fast);
    border: none;
}

.btn-primary-custom:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 28px rgba(78, 120, 94, 0.45);
}

.btn-secondary-custom {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.85rem 1.75rem;
    background: var(--bg-card);
    color: var(--text-primary) !important;
    font-weight: 700;
    font-size: 1rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.btn-secondary-custom:hover {
    border-color: var(--accent-primary);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* Social Icon Badges */
.social-links-grid {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.social-pill {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.social-pill img {
    width: 22px;
    height: 22px;
    object-fit: contain;
    transition: transform var(--transition-fast);
}

.social-pill:hover {
    border-color: var(--accent-primary);
    transform: translateY(-3px);
    box-shadow: var(--shadow-glow);
}

.social-pill:hover img {
    transform: scale(1.15);
}

/* Hero Avatar Card */
.hero-photo-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
}

.avatar-card {
    position: relative;
    width: 100%;
    max-width: 360px;
    border-radius: 28px;
    padding: 12px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.avatar-card::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 30px;
    background: var(--accent-gradient);
    z-index: -1;
    opacity: 0.4;
    filter: blur(12px);
    transition: opacity var(--transition-smooth);
}

.avatar-card:hover {
    transform: translateY(-8px) rotate(1deg);
    box-shadow: var(--shadow-glow), var(--shadow-lg);
}

.avatar-card:hover::before {
    opacity: 0.8;
}

.avatar-img {
    width: 100%;
    height: 380px;
    object-fit: cover;
    border-radius: 20px;
    display: block;
}

.avatar-caption {
    margin-top: 1rem;
    text-align: center;
    padding: 0.5rem;
}

.avatar-caption-name {
    font-size: 1.2rem;
    font-weight: 700;
}

.avatar-caption-sub {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* --- 5. Section Headers & Cards Layout --- */
.section-padding {
    padding: 90px 0;
}

.section-title-wrapper {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 3.5rem auto;
}

.section-eyebrow {
    display: inline-block;
    font-size: 0.85rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
}

.section-main-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-description {
    font-size: 1.1rem;
    color: var(--text-muted);
}

/* Glass Cards */
.glass-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-smooth);
}

.glass-card:hover {
    border-color: var(--border-accent);
    box-shadow: var(--shadow-lg);
}

/* --- 6. Infinite Marquee Ticker --- */
.marquee-container {
    overflow: hidden;
    white-space: nowrap;
    position: relative;
    padding: 1.5rem 0;
    background: var(--bg-panel);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.marquee-content {
    display: inline-flex;
    gap: 3rem;
    animation: marqueeScroll 25s linear infinite;
}

.marquee-item {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.marquee-item img {
    width: 28px;
    height: 28px;
    object-fit: contain;
}

@keyframes marqueeScroll {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* --- 7. Skills Grid & Interactive Filters --- */
.filter-tabs-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2.5rem;
}

.filter-btn {
    padding: 0.6rem 1.4rem;
    border-radius: var(--radius-full);
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.filter-btn.active {
    background: var(--accent-gradient);
    color: #ffffff;
    border-color: transparent;
    box-shadow: 0 4px 15px rgba(78, 120, 94, 0.35);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1.5rem;
}

.skill-card-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.25rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-smooth);
}

.skill-card-item:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.skill-icon-wrapper {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--bg-panel);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.skill-icon-wrapper img {
    width: 28px;
    height: 28px;
    object-fit: contain;
}

.skill-info {
    display: flex;
    flex-direction: column;
}

.skill-name {
    font-size: 1.05rem;
    font-weight: 700;
}

.skill-level {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* --- 8. Timeline Architecture (Experience & Education) --- */
.timeline-wrapper {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: 2rem;
}

.timeline-wrapper::before {
    content: '';
    position: absolute;
    top: 10px;
    bottom: 10px;
    left: 7px;
    width: 2px;
    background: var(--border-color);
}

.timeline-node {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-dot {
    position: absolute;
    left: -2rem;
    top: 6px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-primary);
    border: 3px solid var(--bg-main);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.timeline-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-smooth);
}

.timeline-card:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-md);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.timeline-role {
    font-size: 1.25rem;
    font-weight: 700;
}

.timeline-institution {
    font-size: 0.95rem;
    color: var(--accent-primary);
    font-weight: 600;
}

.timeline-badge {
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-muted);
}

.timeline-bullets {
    padding-left: 1.2rem;
    color: var(--text-secondary);
    font-size: 0.98rem;
}

.timeline-bullets li {
    margin-bottom: 0.5rem;
}

/* --- 9. Modern Projects Showcase --- */
.projects-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.search-box-wrapper {
    position: relative;
    min-width: 280px;
    flex-grow: 1;
    max-width: 400px;
}

.search-input-custom {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border-radius: var(--radius-full);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-size: 0.95rem;
    outline: none;
    transition: all var(--transition-fast);
}

.search-input-custom:focus {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
}

.search-icon-svg {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    fill: var(--text-muted);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 2rem;
}

.project-card-modern {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-smooth);
}

.project-card-modern:hover {
    transform: translateY(-8px);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.project-image-preview {
    position: relative;
    width: 100%;
    height: 220px;
    overflow: hidden;
    background: var(--bg-panel);
}

.project-image-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.project-card-modern:hover .project-image-preview img {
    transform: scale(1.06);
}

.project-body {
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-title {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
}

.project-subtitle {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--accent-primary);
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.problem-solution-box {
    background: var(--bg-panel);
    border-radius: var(--radius-md);
    padding: 1rem;
    margin-bottom: 1.25rem;
    font-size: 0.92rem;
    color: var(--text-secondary);
}

.problem-solution-box strong {
    color: var(--text-primary);
}

.tech-tag-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    margin-top: auto;
}

.tech-tag {
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    background: rgba(78, 120, 94, 0.1);
    border: 1px solid rgba(78, 120, 94, 0.25);
    color: var(--accent-primary);
    font-size: 0.8rem;
    font-weight: 600;
}

.project-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.btn-sm-custom {
    padding: 0.5rem 1rem;
    font-size: 0.88rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    text-decoration: none !important;
}

/* --- 10. Contact Section & Forms --- */
.contact-grid {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 3rem;
}

.contact-info-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    padding: 1.25rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
}

.contact-icon-box {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--bg-panel);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon-box img {
    width: 24px;
    height: 24px;
    object-fit: contain;
}

.contact-form-container-modern {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
}

.form-group-modern {
    margin-bottom: 1.25rem;
}

.form-label-custom {
    display: block;
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
    color: var(--text-secondary);
}

.form-control-custom {
    width: 100%;
    padding: 0.85rem 1rem;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: all var(--transition-fast);
}

.form-control-custom:focus {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-glow);
    background: var(--bg-card);
}

/* --- 11. Footer & Utilities --- */
.site-footer {
    background: var(--bg-panel);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
    margin-top: 5rem;
    text-align: center;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--accent-gradient);
    color: #ffffff;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-fast);
    z-index: 900;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* Animations */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible, .animate-on-scroll.show {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Media Queries */
@media (max-width: 992px) {
    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2.5rem;
    }

    .hero-bio {
        margin: 0 auto 2rem auto;
    }

    .hero-ctas, .social-links-grid {
        justify-content: center;
    }

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

@media (max-width: 768px) {
    .site-header {
        padding: 0 1rem;
    }

    .main-nav {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--bg-card);
        border-bottom: 1px solid var(--border-color);
        padding: 1.5rem;
        flex-direction: column;
        display: none;
        box-shadow: var(--shadow-lg);
    }

    .main-nav.show {
        display: flex;
    }

    .hero-title {
        font-size: 2.3rem;
    }

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