/* ===== CSS Variables - Professional Light Theme with Refined Blue Accents ===== */
:root {
    /* Light Backgrounds */
    --bg-primary: #ffffff;
    --bg-secondary: #fafbfc;
    --bg-tertiary: #f1f5f9;
    --bg-accent: #e0f2fe;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;

    /* Refined Blue Accent */
    --accent-primary: #0369a1;
    --accent-secondary: #0ea5e9;
    --accent-highlight: #38bdf8;
    --accent-light: #e0f2fe;
    --accent-dark: #075985;

    /* Button Colors */
    --warm-accent: #0369a1;
    --warm-hover: #075985;

    /* Gradient Accents - More subtle */
    --gradient-tech: linear-gradient(135deg, #0369a1 0%, #0891b2 100%);
    --gradient-glow: linear-gradient(135deg, rgba(3, 105, 161, 0.1) 0%, rgba(8, 145, 178, 0.05) 100%);

    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --text-light: #94a3b8;

    /* Icon Colors */
    --icon-primary: #0369a1;
    --icon-secondary: #0ea5e9;
    --icon-muted: #0ea5e9;

    /* Borders & Shadows */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-hover: #0ea5e9;

    /* Professional Shadows - Subtler */
    --shadow-soft: 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-medium: 0 4px 12px -2px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 8px 20px -4px rgba(0, 0, 0, 0.1);
    --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
    --shadow-card-hover: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-glow: 0 0 12px rgba(14, 165, 233, 0.15);

    /* Typography */
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing */
    --section-padding: 7rem;
    --container-max: 1200px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.35s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    color: var(--text-secondary);
    line-height: 1.7;
    overflow-x: hidden;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background: var(--accent-secondary);
    color: #ffffff;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--text-primary);
    font-weight: 600;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

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

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

strong {
    color: var(--text-primary);
    font-weight: 600;
}

/* ===== Layout ===== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: var(--section-padding) 0;
    position: relative;
    overflow: hidden;
}

.page-section {
    padding-top: calc(var(--section-padding) + 80px);
    min-height: 100vh;
}

/* Section Background Patterns */
.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 0;
}

/* Very subtle gradient for sections - simplified */
.section.about::before,
.section.skills::before,
.section.experience::before,
.section.education::before,
.section.projects::before,
.section.honors::before {
    background: radial-gradient(ellipse at 50% 0%, rgba(3, 105, 161, 0.02) 0%, transparent 70%);
}

/* Ensure content is above backgrounds */
.section > .container {
    position: relative;
    z-index: 1;
}

/* Background orbs - hidden (removed for cleaner design) */
.section .bg-orb {
    display: none;
}

/* Animated gradient background - very subtle, reduced opacity */
.animated-gradient-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        180deg,
        rgba(3, 105, 161, 0.015) 0%,
        transparent 50%
    );
    pointer-events: none;
    z-index: 0;
}

/* Floating particles - hidden (removed for cleaner design) */
.floating-particles {
    display: none;
}

.particle {
    display: none;
}

/* Moving lines - hidden (removed for cleaner design) */
.moving-lines {
    display: none;
}

.moving-line {
    display: none;
}

/* Pulse rings - hidden (removed for cleaner design) */
.pulse-ring {
    display: none;
}

/* Grid background - hidden (removed for cleaner design) */
.grid-bg {
    display: none;
}

/* Circuit lines - hidden (removed for cleaner design) */
.circuit-line {
    display: none;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    margin-bottom: 3rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

/* ===== Navigation ===== */
.nav-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    transition: all var(--transition-normal);
}

.nav-header.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-soft);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.03em;
    position: relative;
}

.logo-text::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 20px;
    background: var(--accent-secondary);
    border-radius: 2px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
    list-style: none;
}

.nav-links li {
    display: flex;
    align-items: center;
}

.nav-links a {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    padding: 0.5rem 0;
    transition: color var(--transition-fast);
    white-space: nowrap;
}

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

/* Sidebar Menu Button */
.sidebar-menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    color: var(--text-primary);
    cursor: pointer;
    padding: 0.5rem;
    margin-left: 1rem;
    transition: all var(--transition-normal);
}

.sidebar-menu-btn:hover {
    border-color: var(--accent-secondary);
    color: var(--accent-secondary);
    box-shadow: var(--shadow-card);
}

.sidebar-menu-btn i {
    width: 20px;
    height: 20px;
}

/* Sidebar Overlay */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 1998;
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* Sidebar Menu */
.sidebar-menu {
    position: fixed;
    top: 0;
    right: -320px;
    width: 300px;
    height: 100vh;
    background: var(--bg-card);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
    z-index: 1999;
    transition: right var(--transition-normal);
    display: flex;
    flex-direction: column;
}

.sidebar-menu.active {
    right: 0;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-light);
}

.sidebar-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.sidebar-close-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.sidebar-close-btn:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.sidebar-close-btn i {
    width: 20px;
    height: 20px;
}

.sidebar-links {
    list-style: none;
    padding: 1rem;
    flex: 1;
}

.sidebar-links li {
    margin-bottom: 0.5rem;
}

.sidebar-links a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    color: var(--text-secondary);
    font-weight: 500;
    border-radius: 10px;
    transition: all var(--transition-fast);
}

.sidebar-links a:hover {
    background: var(--bg-accent);
    color: var(--accent-primary);
}

.sidebar-links a i {
    width: 20px;
    height: 20px;
    color: var(--accent-secondary);
}

.sidebar-links a:hover i {
    color: var(--accent-primary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn .close-icon {
    display: none;
}

.mobile-menu-btn.active .menu-icon {
    display: none;
}

.mobile-menu-btn.active .close-icon {
    display: block;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: var(--bg-secondary);
}

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

/* Geometric Pattern Background - Tech Circuit Style */
.geometric-pattern {
    position: absolute;
    inset: 0;
    opacity: 0.3;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%230ea5e9' fill-opacity='0.3'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.gradient-mesh {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 30% 20%, rgba(14, 165, 233, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 70% 80%, rgba(6, 182, 212, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(56, 189, 248, 0.05) 0%, transparent 60%);
}

#particleCanvas {
    position: absolute;
    inset: 0;
    opacity: 0.15;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
    max-width: 800px;
}

.profile-container {
    margin-bottom: 2rem;
}

.profile-ring {
    width: 160px;
    height: 160px;
    margin: 0 auto;
    padding: 4px;
    border-radius: 50%;
    background: var(--gradient-tech);
    box-shadow: var(--shadow-medium);
}

.profile-photo {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    background: var(--bg-primary);
    border: 4px solid var(--bg-primary);
}

.hero-name {
    font-size: clamp(2.5rem, 6vw, 4rem);
    margin-bottom: 0.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

.hero-title {
    font-family: var(--font-mono);
    font-size: clamp(0.875rem, 2vw, 1rem);
    color: var(--accent-secondary);
    margin-bottom: 1.5rem;
    min-height: 1.5em;
    font-weight: 500;
}

.hero-tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 550px;
    margin: 0 auto 2rem;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    border-radius: 8px;
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
}

.btn i {
    width: 18px;
    height: 18px;
    stroke-width: 2;
}

.btn-primary {
    background: var(--warm-accent);
    color: #ffffff;
}

.btn-primary:hover {
    background: var(--warm-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-soft);
    color: #ffffff;
}

.btn-secondary {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}

.btn-secondary:hover {
    border-color: var(--accent-secondary);
    background: var(--bg-secondary);
    transform: translateY(-1px);
    color: var(--accent-primary);
}

/* Social Links */
.social-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.social-links a {
    color: var(--icon-muted);
    padding: 0.75rem;
    border-radius: 10px;
    border: 1px solid var(--border-medium);
    background: var(--bg-primary);
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-card);
}

.social-links a i {
    width: 22px;
    height: 22px;
    stroke-width: 2;
}

.social-links a:hover {
    color: var(--accent-secondary);
    border-color: var(--accent-secondary);
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.scroll-indicator:hover {
    transform: translateX(-50%) translateY(-5px);
}

.scroll-text {
    font-size: 0.75rem;
    font-family: var(--font-mono);
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--text-muted);
    transition: color var(--transition-normal);
}

.scroll-indicator:hover .scroll-text {
    color: var(--accent-secondary);
}

.scroll-arrows {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: -8px;
    animation: bounce 2s infinite;
}

.scroll-arrows i {
    width: 24px;
    height: 24px;
    stroke-width: 2;
    color: var(--icon-muted);
    transition: color var(--transition-normal);
}

.scroll-arrows i:first-child {
    margin-bottom: -10px;
    opacity: 0.5;
}

.scroll-indicator:hover .scroll-arrows i {
    color: var(--accent-secondary);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(8px); }
    60% { transform: translateY(4px); }
}

/* Typing cursor */
.hero-title::after {
    content: '|';
    animation: blink 1s step-end infinite;
    color: var(--accent-secondary);
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

/* ===== About Section ===== */
.about {
    background: var(--bg-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1rem;
    line-height: 1.8;
}

.focus-areas {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 2rem;
}

.focus-areas h3 {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

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

.focus-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 0;
    border-bottom: 1px solid var(--border-light);
    transition: all var(--transition-fast);
    color: var(--text-secondary);
}

.focus-list li:last-child {
    border-bottom: none;
}

.focus-list li:hover {
    padding-left: 0.5rem;
    color: var(--text-primary);
}

.focus-list i {
    color: var(--icon-primary);
    width: 20px;
    height: 20px;
    stroke-width: 2;
}

/* ===== Skills Section ===== */
.skills {
    background: var(--bg-secondary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.skill-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 1.75rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
}

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

.skill-icon {
    width: 48px;
    height: 48px;
    background: var(--gradient-tech);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
    transition: all var(--transition-normal);
}

.skill-icon i {
    color: #ffffff;
    width: 24px;
    height: 24px;
}

.skill-card h3 {
    font-size: 1.05rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    padding: 0.3rem 0.6rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 4px;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.skill-tag:hover {
    border-color: var(--accent-secondary);
    color: var(--accent-primary);
}

/* ===== Experience Section ===== */
.experience {
    background: var(--bg-primary);
}

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

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--border-light);
}

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

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -2rem;
    top: 0;
    width: 10px;
    height: 10px;
    background: var(--accent-secondary);
    border-radius: 50%;
    transform: translateX(-4.5px);
    border: 2px solid var(--bg-primary);
}

.timeline-content {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 1.75rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
}

.timeline-content:hover {
    border-color: var(--border-hover);
}

.timeline-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.company-logo {
    width: 52px;
    height: 52px;
    border-radius: 12px;
    object-fit: contain;
    background: var(--bg-secondary);
    padding: 6px;
    flex-shrink: 0;
    border: 1px solid var(--border-light);
}

.timeline-header-text h3 {
    font-size: 1.15rem;
    margin-bottom: 0.25rem;
}

.timeline-company {
    color: var(--accent-secondary);
    font-weight: 500;
}

.timeline-date {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    margin: 0.75rem 0 0.25rem 0;
}

.timeline-date i {
    width: 16px;
    height: 16px;
    color: var(--icon-primary);
    stroke-width: 2;
}

.timeline-location {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-bottom: 0.75rem;
}

.timeline-location i {
    width: 16px;
    height: 16px;
    color: var(--icon-primary);
    stroke-width: 2;
}

.timeline-details {
    list-style: none;
    margin-bottom: 1rem;
}

.timeline-details li {
    position: relative;
    padding-left: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.timeline-details li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.6em;
    width: 6px;
    height: 6px;
    background: var(--accent-secondary);
    border-radius: 50%;
}

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.timeline-tags span {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    padding: 0.25rem 0.5rem;
    background: var(--accent-light);
    border-radius: 4px;
    color: var(--accent-dark);
    transition: all var(--transition-fast);
}

.timeline-tags span:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

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

.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-light);
    border-radius: 12px;
    overflow: hidden;
    transition: all var(--transition-normal);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-card);
}

.project-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-card-hover);
}

/* Project Thumbnail */
.project-thumbnail {
    position: relative;
    width: 100%;
    height: 180px;
    overflow: hidden;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    transition: transform 0.4s ease;
}

/* For images that need contain instead of cover */
.project-thumbnail.contain-img img {
    object-fit: contain;
    padding: 12px;
    background: var(--bg-secondary);
}

.project-card:hover .project-thumbnail img {
    transform: scale(1.05);
}

/* Tech icon overlay on thumbnail */
.project-thumbnail .tech-overlay {
    position: absolute;
    top: 10px;
    right: 10px;
    display: flex;
    gap: 6px;
    z-index: 2;
}

.project-thumbnail .tech-badge {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(4px);
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.65rem;
    font-family: var(--font-mono);
    color: var(--accent-dark);
    font-weight: 500;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

/* Placeholder for projects without images */
.project-thumbnail.placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-tech);
}

.project-thumbnail.placeholder i,
.project-thumbnail.placeholder .placeholder-icon {
    width: 48px;
    height: 48px;
    color: rgba(255, 255, 255, 0.85);
    stroke-width: 1.5;
}

.project-card-content {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

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

.project-folder {
    color: var(--icon-primary);
    width: 40px;
    height: 40px;
    stroke-width: 1.5;
}

.project-links a {
    color: var(--icon-muted);
    transition: color var(--transition-fast);
}

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

.project-links a i {
    width: 22px;
    height: 22px;
    stroke-width: 2;
}

.project-title {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    transition: color var(--transition-fast);
    color: var(--text-primary);
}

.project-card:hover .project-title {
    color: var(--accent-secondary);
}

.project-date {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.project-description {
    font-size: 0.9rem;
    color: var(--text-secondary);
    flex-grow: 1;
    margin-bottom: 1rem;
    line-height: 1.7;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.project-tags span {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--accent-secondary);
    padding: 0.2rem 0.5rem;
    background: var(--accent-light);
    border-radius: 4px;
    transition: all var(--transition-fast);
}

.project-tags span:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

.view-all-projects {
    text-align: center;
    margin-top: 3rem;
}

.view-all-projects .btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

/* ===== Education Section ===== */
.education {
    background: var(--bg-primary);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

.education-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 2rem;
    display: flex;
    gap: 1.5rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
}

.education-card:hover {
    border-color: var(--border-hover);
}

.education-logo {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    border-radius: 12px;
    object-fit: contain;
    background: var(--bg-secondary);
    padding: 8px;
    border: 1px solid var(--border-light);
}

.education-content h3 {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.education-school {
    color: var(--accent-secondary);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.education-date {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.education-skills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.75rem;
}

.education-skills span {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    padding: 0.25rem 0.6rem;
    background: var(--accent-light);
    border-radius: 4px;
    color: var(--accent-dark);
    transition: all var(--transition-fast);
}

.education-skills span:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

.education-highlight {
    font-size: 0.85rem;
    color: var(--accent-secondary);
    margin-top: 0.5rem;
}

/* ===== Honors Section ===== */
.honors {
    background: var(--bg-secondary);
}

.honors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.honor-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
}

.honor-card:hover {
    border-color: var(--border-hover);
}

.subsection-title {
    font-size: 1rem;
    color: var(--text-primary);
    margin: 2rem 0 1rem 0;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-light);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.subsection-title:first-of-type {
    margin-top: 0;
}

.cert-logo {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: 10px;
    object-fit: contain;
    background: var(--bg-secondary);
    padding: 6px;
    border: 1px solid var(--border-light);
}

.credential-id {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.credential-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.8rem;
    color: var(--accent-secondary);
    margin-top: 0.5rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.credential-link:hover {
    color: var(--accent-primary);
}

.credential-link i {
    width: 16px;
    height: 16px;
    stroke-width: 2;
}

.cert-skills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-top: 0.5rem;
}

.cert-skills span {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    padding: 0.2rem 0.5rem;
    background: var(--accent-light);
    border-radius: 4px;
    color: var(--accent-dark);
    transition: all var(--transition-fast);
}

.cert-skills span:hover {
    background: var(--accent-secondary);
    color: #ffffff;
}

/* Award Icons */
.award-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-soft);
}

.award-icon i {
    width: 24px;
    height: 24px;
}

.award-icon.gold {
    background: linear-gradient(135deg, #ffd700, #ffb300);
}

.award-icon.gold i {
    color: #5d4e00;
}

.award-icon.silver {
    background: linear-gradient(135deg, #e8e8e8, #c0c0c0);
}

.award-icon.silver i {
    color: #4a4a4a;
}

.award-icon.bronze {
    background: linear-gradient(135deg, #cd7f32, #b87333);
}

.award-icon.bronze i {
    color: #3d2914;
}

.honor-content h3 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.honor-org {
    color: var(--accent-secondary);
    font-size: 0.875rem;
}

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

.honor-description {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* Award Media */
.award-media {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.video-thumbnail {
    position: relative;
    display: block;
    width: 140px;
    height: 80px;
    border-radius: 8px;
    overflow: hidden;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
    cursor: pointer;
}

.video-thumbnail:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-medium);
}

.video-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.play-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast);
}

.video-thumbnail:hover .play-overlay {
    background: rgba(0, 0, 0, 0.25);
}

.play-overlay i {
    width: 40px;
    height: 40px;
    color: #fff;
}

.photo-overlay {
    background: rgba(0, 0, 0, 0.3);
}

.cert-thumbnail {
    position: relative;
    width: 140px;
    height: 80px;
    border-radius: 8px;
    overflow: hidden;
    transition: all var(--transition-normal);
    cursor: pointer;
    box-shadow: var(--shadow-card);
}

.cert-thumbnail:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-medium);
}

.cert-preview {
    width: 100%;
    height: 100%;
    background: var(--accent-light);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-light);
}

.cert-preview i {
    width: 32px;
    height: 32px;
    color: var(--accent-secondary);
}

.media-label {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 0.3rem;
    background: rgba(15, 23, 42, 0.85);
    color: #fff;
    font-size: 0.65rem;
    text-align: center;
    font-weight: 500;
}

.drone-award-card {
    flex-direction: column;
}

.drone-award-card .award-icon {
    align-self: flex-start;
}

/* Clickable cards */
.clickable-card,
.clickable-project {
    cursor: pointer;
}

.clickable-card:hover,
.clickable-project:hover {
    border-color: var(--accent-secondary);
}

.view-cert-hint,
.view-details-hint {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    color: var(--accent-secondary);
    margin-top: 0.75rem;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.view-cert-hint i,
.view-details-hint i {
    width: 16px;
    height: 16px;
    stroke-width: 2;
}

.clickable-card:hover .view-cert-hint,
.clickable-project:hover .view-details-hint {
    opacity: 1;
}

/* YouTube link */
.project-links .youtube-link {
    color: #dc2626;
}

.project-links .youtube-link:hover {
    color: #b91c1c;
}

/* NDA Badge */
.nda-badge {
    background: var(--accent-secondary);
    color: #fff;
    font-size: 0.65rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    letter-spacing: 0.5px;
}

/* NDA Modal */
.nda-modal-content {
    max-width: 480px;
    height: auto;
    text-align: center;
}

.nda-modal-body {
    padding: 1rem;
}

.nda-icon {
    width: 72px;
    height: 72px;
    margin: 0 auto 1.5rem;
    background: var(--accent-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--border-medium);
}

.nda-icon i {
    width: 36px;
    height: 36px;
    color: var(--accent-secondary);
}

.nda-modal-body h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.nda-message {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.nda-tagline {
    color: var(--accent-secondary);
    font-style: italic;
    font-size: 1rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--accent-light);
    border-radius: 8px;
    border-left: 3px solid var(--accent-secondary);
}

.nda-details {
    color: var(--text-muted);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.btn-contact-nda {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--accent-secondary);
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-soft);
}

.btn-contact-nda:hover {
    background: var(--accent-primary);
    transform: translateY(-2px);
    color: #fff;
    box-shadow: var(--shadow-medium);
}

.btn-contact-nda i {
    width: 18px;
    height: 18px;
}

/* ===== Publications Section ===== */
.publications {
    background: var(--bg-primary);
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.publication-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 1.75rem;
    display: flex;
    gap: 1.5rem;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-card);
}

.publication-card:hover {
    border-color: var(--border-hover);
}

.publication-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: var(--gradient-tech);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.publication-icon i {
    color: #ffffff;
    width: 24px;
    height: 24px;
}

.publication-title {
    font-size: 1.05rem;
    margin-bottom: 0.5rem;
}

.publication-authors {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.publication-venue {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 0.75rem;
}

.publication-abstract {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
    margin-bottom: 1rem;
}

.publication-links {
    display: flex;
    gap: 1rem;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.8rem;
    color: var(--icon-primary);
    font-weight: 500;
}

.publication-link i {
    width: 16px;
    height: 16px;
    stroke-width: 2;
}

.publication-link:hover {
    color: var(--accent-secondary);
}

/* ===== Contact Section ===== */
.contact {
    background: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 4rem;
}

.contact-intro {
    font-size: 1.05rem;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    padding: 0.875rem;
    border-radius: 10px;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.contact-method:hover {
    background: var(--bg-card);
    border-color: var(--border-light);
    color: var(--accent-secondary);
    box-shadow: var(--shadow-card);
}

.contact-method i {
    color: var(--icon-primary);
    width: 22px;
    height: 22px;
    stroke-width: 2;
}

.contact-form {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-card);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-secondary);
    background: var(--bg-card);
    box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    width: 100%;
    justify-content: center;
}

/* ===== Certificate Modal ===== */
.certificate-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 10000;
    align-items: center;
    justify-content: center;
}

.certificate-modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.75);
    backdrop-filter: blur(8px);
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 900px;
    height: 85vh;
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow-hover);
    display: flex;
    flex-direction: column;
    animation: modalSlideIn 0.25s ease;
}

@keyframes modalSlideIn {
    from { opacity: 0; transform: scale(0.95) translateY(10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    z-index: 10;
}

.modal-close:hover {
    background: var(--accent-secondary);
    border-color: var(--accent-secondary);
    color: #ffffff;
}

.modal-close i {
    width: 20px;
    height: 20px;
}

.modal-title {
    font-size: 1.15rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    padding-right: 3rem;
    font-weight: 600;
}

.modal-content iframe {
    flex: 1;
    width: 100%;
    border-radius: 8px;
    background: var(--bg-secondary);
}

/* Image modal */
.image-modal-content {
    height: auto;
    max-height: 90vh;
}

.image-modal-content img {
    max-width: 100%;
    max-height: calc(90vh - 100px);
    object-fit: contain;
    border-radius: 8px;
}

/* Video modal */
.video-modal-content {
    max-width: 700px;
    height: auto;
}

/* Local video modal (LIO-SAM, Dead Reckoning) */
.local-video-modal-content {
    max-width: 900px;
    height: auto;
    align-items: center;
}

.local-video-modal-content video {
    width: 100%;
    max-height: calc(85vh - 100px);
    border-radius: 8px;
    object-fit: contain;
    background: #000;
}

.video-preview-wrapper {
    position: relative;
    width: 100%;
    border-radius: 8px;
    overflow: hidden;
}

.video-preview-wrapper img {
    width: 100%;
    display: block;
    border-radius: 8px;
}

.youtube-play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    background: rgba(220, 38, 38, 0.95);
    color: #fff;
    text-decoration: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-medium);
}

.youtube-play-btn:hover {
    background: #dc2626;
    transform: translate(-50%, -50%) scale(1.05);
    color: #fff;
}

.youtube-play-btn i {
    width: 22px;
    height: 22px;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-light);
    padding: 3rem 0;
}

.footer-content {
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2.5rem;
    margin-bottom: 1.5rem;
}

.footer-links a {
    color: var(--text-muted);
    font-size: 0.875rem;
}

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

.footer-social {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.footer-social a {
    color: var(--icon-muted);
    padding: 0.5rem;
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.footer-social a:hover {
    color: var(--accent-secondary);
    background: var(--accent-light);
}

.footer-social a i {
    width: 22px;
    height: 22px;
    stroke-width: 2;
}

.footer-copyright {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-bottom: 0.25rem;
}

.footer-tagline {
    color: var(--text-light);
    font-size: 0.75rem;
}

/* ===== Animations ===== */
/* Elements are visible by default - JS will handle animations */
.animate-on-scroll {
    transition: opacity 0.6s ease, transform 0.6s ease;
}

/* Only hide elements when CSS-only animation fallback is used (no GSAP) */
.animate-on-scroll.will-animate {
    opacity: 0;
    transform: translateY(30px);
}

/* Show when animated by IntersectionObserver (CSS fallback) */
.animate-on-scroll.will-animate.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Hero animations */
.hero-content .profile-container,
.hero-content .hero-name,
.hero-content .hero-title,
.hero-content .hero-tagline,
.hero-content .hero-cta,
.hero-content .social-links {
    opacity: 0;
    transform: translateY(20px);
}

/* Page load animation */
main {
    animation: pageLoad 0.4s ease-out;
}

@keyframes pageLoad {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 4rem 0;
    }

    .container {
        padding: 0 1.5rem;
    }

    .mobile-menu-btn {
        display: block;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(12px);
        flex-direction: column;
        align-items: center;
        padding: 2rem;
        gap: 1.5rem;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
        border-bottom: 1px solid var(--border-light);
        box-shadow: var(--shadow-medium);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .sidebar-menu-btn {
        display: none;
    }

    .profile-ring {
        width: 140px;
        height: 140px;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 240px;
        justify-content: center;
    }

    .education-card {
        flex-direction: column;
        text-align: center;
    }

    .education-logo {
        margin: 0 auto;
    }

    .publication-card {
        flex-direction: column;
    }

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

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

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

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

    .timeline {
        padding-left: 1.5rem;
    }

    .timeline-marker {
        left: -1.5rem;
    }

    .award-media {
        flex-direction: column;
        align-items: flex-start;
    }

    .honor-card {
        flex-direction: column;
    }

    .drone-award-card {
        flex-direction: column;
    }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .animate-on-scroll {
        opacity: 1;
        transform: none;
    }

    .hero-content .profile-container,
    .hero-content .hero-name,
    .hero-content .hero-title,
    .hero-content .hero-tagline,
    .hero-content .hero-cta,
    .hero-content .social-links {
        opacity: 1;
        transform: none;
    }
}

/* ===== Utility Classes ===== */
.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;
}