/* ============================================
   Portfolio — Design System & Styles
   ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
    /* Colors — Light Mode */
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-card: rgba(255, 255, 255, 0.8);
    --bg-card-hover: rgba(255, 255, 255, 0.95);
    --bg-nav: rgba(248, 250, 252, 0.85);

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;
    --text-inverse: #f8fafc;

    --accent: #0891b2;
    --accent-light: #06b6d4;
    --accent-dark: #0e7490;
    --accent-glow: rgba(6, 182, 212, 0.15);
    --accent-gradient: linear-gradient(135deg, #06b6d4, #0891b2, #7c3aed);

    --border: rgba(15, 23, 42, 0.08);
    --border-hover: rgba(15, 23, 42, 0.15);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06), 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.08), 0 4px 16px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.1);

    --tag-bg: rgba(6, 182, 212, 0.08);
    --tag-text: #0891b2;
    --tag-border: rgba(6, 182, 212, 0.2);

    --success: #10b981;
    --timeline-line: rgba(6, 182, 212, 0.2);
    --timeline-dot: #06b6d4;

    /* Spacing */
    --section-gap: 6rem;
    --container-max: 1100px;
    --nav-height: 70px;
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Dark Mode ---------- */
.dark {
    --bg-primary: #0b1120;
    --bg-secondary: #111827;
    --bg-card: rgba(17, 24, 39, 0.7);
    --bg-card-hover: rgba(17, 24, 39, 0.9);
    --bg-nav: rgba(11, 17, 32, 0.9);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;
    --text-inverse: #0f172a;

    --accent: #22d3ee;
    --accent-light: #67e8f9;
    --accent-dark: #06b6d4;
    --accent-glow: rgba(34, 211, 238, 0.12);

    --border: rgba(248, 250, 252, 0.06);
    --border-hover: rgba(248, 250, 252, 0.12);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.5);

    --tag-bg: rgba(34, 211, 238, 0.1);
    --tag-text: #22d3ee;
    --tag-border: rgba(34, 211, 238, 0.2);

    --timeline-line: rgba(34, 211, 238, 0.15);
    --timeline-dot: #22d3ee;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition-base), color var(--transition-base);
    overflow-x: hidden;
}

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

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

img {
    max-width: 100%;
    display: block;
}

/* ---------- Background Decoration ---------- */
body::before {
    content: '';
    position: fixed;
    top: -50%;
    right: -30%;
    width: 80vw;
    height: 80vw;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

body::after {
    content: '';
    position: fixed;
    bottom: -40%;
    left: -20%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(124, 58, 237, 0.06) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

/* ---------- Container ---------- */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1.5rem;
    position: relative;
    z-index: 1;
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: var(--bg-nav);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background-color var(--transition-base), border-color var(--transition-base);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    padding: 0.5rem 0.875rem;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
    background: var(--accent-glow);
}

/* Nav CV download button */
.nav-cv-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.45rem 1rem;
    background: var(--accent-gradient);
    color: #fff !important;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
    margin-left: 0.5rem;
    flex-shrink: 0;
}

.nav-cv-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(6, 182, 212, 0.3);
    color: #fff !important;
}

/* Dark mode toggle */
.theme-toggle {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    width: 42px;
    height: 42px;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.15rem;
    transition: all var(--transition-fast);
    margin-left: 0.5rem;
    flex-shrink: 0;
}

.theme-toggle:hover {
    border-color: var(--accent);
    color: var(--accent);
    box-shadow: 0 0 20px var(--accent-glow);
}

/* Mobile hamburger */
.nav-hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--nav-height) + 2rem) 0 6rem;
    position: relative;
}

.hero-content {
    text-align: center;
    max-width: 750px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--tag-bg);
    border: 1px solid var(--tag-border);
    color: var(--tag-text);
    padding: 0.4rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    margin-bottom: 1.5rem;
    text-transform: uppercase;
}

.hero-name {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 900;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
}

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

.hero-title {
    font-size: clamp(1.1rem, 2.5vw, 1.4rem);
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 0.75rem;
}

.hero-location {
    font-size: 0.95rem;
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    margin-bottom: 2rem;
}

.hero-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.hero-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    backdrop-filter: blur(8px);
}

.hero-link:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-glow);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.hero-link.primary {
    background: var(--accent);
    color: var(--text-inverse);
    border-color: var(--accent);
}

.hero-link.primary:hover {
    background: var(--accent-dark);
    color: var(--text-inverse);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(6, 182, 212, 0.3);
}

.hero-scroll-hint {
    color: var(--text-tertiary);
    font-size: 0.8rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 3rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-8px);
    }
}

/* ============================================
   SECTION COMMON
   ============================================ */
.section {
    padding: var(--section-gap) 0;
}

.section-header {
    margin-bottom: 3rem;
}

.section-label {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-top: 0.75rem;
    max-width: 600px;
}

/* ============================================
   ABOUT / SUMMARY
   ============================================ */
.about-grid {
    display: grid;
    gap: 1rem;
}

.about-card {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.25rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
}

.about-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.about-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--accent-glow);
    border: 1px solid var(--tag-border);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    font-size: 1.1rem;
}

.about-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.65;
}

/* ============================================
   EXPERIENCE
   ============================================ */
.experience-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2.5rem;
    align-items: center;
}

.search-wrapper {
    position: relative;
    flex: 1;
    min-width: 250px;
    max-width: 400px;
}

.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
    font-size: 0.9rem;
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    outline: none;
    transition: all var(--transition-fast);
    backdrop-filter: blur(8px);
}

.search-input::placeholder {
    color: var(--text-tertiary);
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.tag-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.tag-filter {
    padding: 0.35rem 0.85rem;
    border-radius: var(--radius-full);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-tertiary);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tag-filter:hover,
.tag-filter.active {
    background: var(--tag-bg);
    border-color: var(--tag-border);
    color: var(--tag-text);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 5px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--timeline-line);
}

.timeline-item {
    position: relative;
    margin-bottom: 2.5rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2rem;
    top: 1.75rem;
    width: 12px;
    height: 12px;
    background: var(--bg-primary);
    border: 3px solid var(--timeline-dot);
    border-radius: 50%;
    z-index: 2;
    transform: translateX(calc(-50% + 6px));
}

.timeline-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
}

.timeline-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.timeline-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
}

.timeline-role {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.timeline-date {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    font-weight: 500;
    white-space: nowrap;
    background: var(--bg-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
}

.timeline-company {
    font-size: 0.95rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.timeline-location {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    margin-bottom: 0.5rem;
}

.timeline-topic {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
    padding: 0.5rem 0.75rem;
    background: var(--accent-glow);
    border-left: 3px solid var(--accent);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin-bottom: 1rem;
}

.timeline-bullets {
    list-style: none;
    margin-bottom: 1.25rem;
}

.timeline-bullets li {
    position: relative;
    padding-left: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.6;
}

.timeline-bullets li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.tag {
    display: inline-block;
    padding: 0.2rem 0.65rem;
    background: var(--tag-bg);
    border: 1px solid var(--tag-border);
    color: var(--tag-text);
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    letter-spacing: 0.01em;
}

.no-results {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-tertiary);
    font-size: 0.95rem;
}

/* ============================================
   PROJECTS
   ============================================ */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.project-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.project-header {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.project-emoji {
    font-size: 2rem;
    line-height: 1;
    flex-shrink: 0;
}

.project-title {
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.3;
}

.project-sdk {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    margin-top: 0.2rem;
}

.project-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    flex: 1;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
}

.project-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.project-link:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.project-link.hf:hover {
    background: var(--tag-bg);
    border-color: var(--tag-border);
    color: var(--tag-text);
}

.project-link.gh:hover {
    background: rgba(51, 51, 51, 0.1);
    border-color: rgba(51, 51, 51, 0.3);
    color: var(--text-primary);
}

.project-link.arxiv:hover {
    background: rgba(185, 28, 28, 0.08);
    border-color: rgba(185, 28, 28, 0.25);
    color: #b91c1c;
}

/* ============================================
   SKILLS & EXPERTISE
   ============================================ */
.skills-section-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.skill-category {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
}

.skill-category:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.skill-category-title {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.skill-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.skill-chip {
    padding: 0.35rem 0.8rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.skill-chip:hover {
    background: var(--tag-bg);
    border-color: var(--tag-border);
    color: var(--tag-text);
    transform: translateY(-1px);
}

/* Expertise subsection */
.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.expertise-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
}

.expertise-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.expertise-card-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.expertise-list {
    list-style: none;
}

.expertise-list li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 0.3rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.expertise-list li::before {
    content: '◆';
    font-size: 0.45rem;
    color: var(--accent);
}

/* ============================================
   EDUCATION
   ============================================ */
.education-grid {
    display: grid;
    gap: 1.5rem;
}

.edu-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 1.5rem;
}

.edu-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.edu-icon {
    width: 52px;
    height: 52px;
    background: var(--accent-glow);
    border: 1px solid var(--tag-border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

.edu-degree {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.edu-institution {
    font-size: 0.95rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 0.2rem;
}

.edu-meta {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    margin-bottom: 0.75rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.edu-bullets {
    list-style: none;
}

.edu-bullets li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 0.2rem 0;
    padding-left: 1rem;
    position: relative;
}

.edu-bullets li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* ============================================
   REFERENCES
   ============================================ */
.references-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.ref-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
}

.ref-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.ref-name {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.ref-title {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.15rem;
}

.ref-org {
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.ref-email {
    font-size: 0.8rem;
    font-family: 'JetBrains Mono', monospace;
    color: var(--text-tertiary);
}

/* ============================================
   CONTACT
   ============================================ */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.contact-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    backdrop-filter: blur(12px);
    transition: all var(--transition-base);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.contact-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.contact-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: var(--accent-glow);
    border: 1px solid var(--tag-border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    font-size: 1.2rem;
}

.contact-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-tertiary);
    margin-bottom: 0.25rem;
}

.contact-value {
    font-size: 0.79rem;
    color: var(--text-primary);
    font-weight: 500;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.4rem;
}

.contact-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 2rem;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.contact-link:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-glow);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Copy button */
.copy-btn {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-tertiary);
    padding: 0.35rem 0.7rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    margin-top: 0.5rem;
    margin-left: 0;
}

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

/* ============================================
   FOOTER
   ============================================ */
.footer {
    padding: 3rem 0;
    border-top: 1px solid var(--border);
    text-align: center;
}

.footer-text {
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

/* ============================================
   TOAST NOTIFICATION
   ============================================ */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text-primary);
    color: var(--bg-primary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 500;
    box-shadow: var(--shadow-xl);
    z-index: 9999;
    opacity: 0;
    transition: all var(--transition-base);
    pointer-events: none;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast.success {
    background: var(--success);
    color: #fff;
}

/* ============================================
   SCROLL ANIMATIONS
   ============================================ */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Stagger children */
.stagger>* {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.stagger.visible>*:nth-child(1) {
    transition-delay: 0.05s;
}

.stagger.visible>*:nth-child(2) {
    transition-delay: 0.1s;
}

.stagger.visible>*:nth-child(3) {
    transition-delay: 0.15s;
}

.stagger.visible>*:nth-child(4) {
    transition-delay: 0.2s;
}

.stagger.visible>*:nth-child(5) {
    transition-delay: 0.25s;
}

.stagger.visible>*:nth-child(6) {
    transition-delay: 0.3s;
}

.stagger.visible>*:nth-child(7) {
    transition-delay: 0.35s;
}

.stagger.visible>*:nth-child(8) {
    transition-delay: 0.4s;
}

.stagger.visible>* {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   CV DOWNLOAD BUTTON
   ============================================ */
.cv-download-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent-gradient);
    color: #fff;
    border: none;
    border-radius: var(--radius-full);
    font-size: 0.9rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.cv-download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(6, 182, 212, 0.3);
    color: #fff;
}

/* ============================================
   RESPONSIVE — MOBILE
   ============================================ */
@media (max-width: 768px) {
    :root {
        --section-gap: 4rem;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: 0;
        width: min(300px, 80vw);
        height: 100vh;
        background: var(--bg-primary);
        flex-direction: column;
        align-items: flex-start;
        padding: calc(var(--nav-height) + 1rem) 1.5rem 2rem;
        gap: 0.25rem;
        transform: translateX(100%);
        transition: transform var(--transition-base);
        box-shadow: var(--shadow-xl);
        z-index: 999;
        border-left: 1px solid var(--border);
    }

    .nav-links.open {
        transform: translateX(0);
    }

    .nav-links a {
        width: 100%;
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }

    .nav-hamburger {
        display: flex;
    }

    .hero-content {
        padding: 0 0.5rem;
    }

    .hero-name {
        font-size: clamp(2rem, 8vw, 3rem);
    }

    .hero-links {
        flex-direction: column;
        align-items: stretch;
        padding: 0 1rem;
    }

    .timeline {
        padding-left: 1.25rem;
    }

    .timeline-item::before {
        left: -1.25rem;
        width: 10px;
        height: 10px;
        transform: translateX(calc(-50% + 5px));
    }

    .timeline-card {
        padding: 1.25rem;
    }

    .timeline-header {
        flex-direction: column;
        gap: 0.5rem;
    }

    .experience-controls {
        flex-direction: column;
    }

    .search-wrapper {
        max-width: 100%;
    }

    .edu-card {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .skills-section-grid {
        grid-template-columns: 1fr;
    }

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

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

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

@media (max-width: 480px) {
    .hero-name {
        font-size: 2rem;
    }

    .container {
        padding: 0 1rem;
    }
}

/* Print styles */
@media print {

    .navbar,
    .theme-toggle,
    .nav-hamburger,
    .hero-scroll-hint,
    .search-wrapper,
    .tag-filters,
    .copy-btn {
        display: none !important;
    }

    body {
        background: #fff;
        color: #000;
    }

    .section {
        padding: 1rem 0;
    }
}