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

:root {
    /* Color Palette - Cybersecurity Themed */
    --color-primary: #00D9FF;
    --color-primary-dark: #00A8CC;
    --color-secondary: #7B2CBF;
    --color-accent: #FF006E;
    --color-success: #06FFA5;

    --color-bg: #0A0E27;
    --color-bg-alt: #111530;
    --color-bg-card: #1A1F3A;
    --color-bg-hover: #222847;

    --color-text: #E8EAED;
    --color-text-muted: #9BA3AF;
    --color-text-light: #C1C9D2;

    --color-border: #2A3150;
    --color-border-light: #3A4260;

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Layout */
    --container-width: 1200px;
    --border-radius: 12px;
    --border-radius-sm: 8px;

    /* Mobile bottom navigation */
    --bottom-nav-height: 64px;

    /* Transitions */
    --transition-speed: 0.3s;
    --transition-ease: cubic-bezier(0.4, 0, 0.2, 1);

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(0, 217, 255, 0.3);
}

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

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ====================================
   Navigation
   ==================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 14, 39, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    transition: all var(--transition-speed) var(--transition-ease);
}

.nav.scrolled {
    background: rgba(10, 14, 39, 0.95);
    box-shadow: var(--shadow-md);
}

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

.nav-logo {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
}

.logo-bracket {
    color: var(--color-primary);
}

.logo-text {
    margin: 0 0.25rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--color-text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-speed) var(--transition-ease);
    position: relative;
}

/* Hide bottom-tab icons by default (desktop); shown in mobile styles */
.nav-icon {
    display: none;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width var(--transition-speed) var(--transition-ease);
}

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

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

/* Header Home button (right side) */
.nav-home-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    margin-left: var(--spacing-md);
    border: 1px solid var(--color-border-light);
    border-radius: 50%;
    color: var(--color-text-light);
    text-decoration: none;
    background: transparent;
    transition: all var(--transition-speed) var(--transition-ease);
}

.nav-home-btn:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

.nav-home-btn svg {
    display: block;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: all var(--transition-speed) var(--transition-ease);
}

/* ====================================
   Hero Section
   ==================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    padding-top: 80px;
}

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

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--color-border) 1px, transparent 1px),
        linear-gradient(90deg, var(--color-border) 1px, transparent 1px);
    background-size: 50px 50px;
    opacity: 0.3;
    animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
    0% { transform: translate(0, 0); }
    100% { transform: translate(50px, 50px); }
}

.gradient-overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 50%,
        rgba(0, 217, 255, 0.15) 0%,
        rgba(123, 44, 191, 0.1) 25%,
        transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    padding: var(--spacing-3xl) var(--spacing-lg);
}

.hero-tag {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary);
    background: rgba(0, 217, 255, 0.1);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 50px;
    border: 1px solid rgba(0, 217, 255, 0.3);
    margin-bottom: var(--spacing-lg);
}

.terminal-prompt {
    color: var(--color-success);
    margin-right: 0.5rem;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-light);
    max-width: 700px;
    margin-bottom: var(--spacing-xl);
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-3xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-speed) var(--transition-ease);
    cursor: pointer;
    border: none;
    font-family: var(--font-primary);
}

.btn-primary {
    background: var(--color-primary);
    color: var(--color-bg);
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.4);
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    box-shadow: 0 0 30px rgba(0, 217, 255, 0.6);
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    border: 2px solid var(--color-border-light);
}

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

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-text-muted);
    font-size: 0.875rem;
    font-family: var(--font-mono);
}

.scroll-arrow {
    width: 20px;
    height: 30px;
    border: 2px solid var(--color-primary);
    border-radius: 15px;
    position: relative;
}

.scroll-arrow::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--color-primary);
    border-radius: 2px;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0%, 100% { opacity: 0; top: 8px; }
    50% { opacity: 1; top: 12px; }
}

/* ====================================
   Section Styles
   ==================================== */
.section {
    padding: var(--spacing-3xl) 0;
}

.section-header {
    margin-bottom: var(--spacing-xl);
}

.section-tag {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary);
    display: block;
    margin-bottom: var(--spacing-sm);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    color: var(--color-text);
}

.lead {
    font-size: 1.25rem;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: var(--spacing-lg);
}

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

.about-text p {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.stat-card {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: all var(--transition-speed) var(--transition-ease);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ====================================
   Expertise Section
   ==================================== */
.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.expertise-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    transition: all var(--transition-speed) var(--transition-ease);
}

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

.expertise-icon {
    width: 60px;
    height: 60px;
    background: rgba(0, 217, 255, 0.1);
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.expertise-icon svg {
    color: var(--color-primary);
}

.expertise-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

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

.expertise-list li {
    color: var(--color-text-light);
    padding: var(--spacing-xs) 0;
    padding-left: 1.5rem;
    position: relative;
}

.expertise-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

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

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

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-2xl);
    padding-left: var(--spacing-xl);
}

.timeline-marker {
    position: absolute;
    left: -0.5rem;
    top: 0.25rem;
    width: 1rem;
    height: 1rem;
    background: var(--color-primary);
    border: 3px solid var(--color-bg-alt);
    border-radius: 50%;
    box-shadow: 0 0 0 4px rgba(0, 217, 255, 0.2);
}

.timeline-period {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.timeline-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.timeline-company {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.timeline-details {
    list-style: none;
}

.timeline-details li {
    color: var(--color-text-light);
    padding: var(--spacing-xs) 0;
    padding-left: 1.5rem;
    position: relative;
}

.timeline-details li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 1.2rem;
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-xl);
}

.project-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    transition: all var(--transition-speed) var(--transition-ease);
    display: flex;
    flex-direction: column;
}

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

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.project-icon {
    width: 60px;
    height: 60px;
    background: rgba(0, 217, 255, 0.1);
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-icon svg {
    color: var(--color-primary);
}

.project-github {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 217, 255, 0.1);
    border-radius: 50%;
    color: var(--color-primary);
    transition: all var(--transition-speed) var(--transition-ease);
}

.project-github:hover {
    background: var(--color-primary);
    color: var(--color-bg);
    transform: scale(1.1);
}

.project-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.project-description {
    font-size: 1.125rem;
    color: var(--color-text-light);
    line-height: 1.7;
    margin-bottom: var(--spacing-lg);
}

.project-features {
    margin-bottom: var(--spacing-lg);
}

.project-features h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.project-features h4:not(:first-child) {
    margin-top: var(--spacing-lg);
}

.project-features ul {
    list-style: none;
}

.project-features li {
    color: var(--color-text-light);
    padding: var(--spacing-xs) 0;
    padding-left: 1.5rem;
    position: relative;
    font-size: 0.95rem;
}

.project-features li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-primary);
    background: rgba(0, 217, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 50px;
    border: 1px solid rgba(0, 217, 255, 0.3);
}

.project-footer {
    margin-top: auto;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-speed) var(--transition-ease);
}

.project-link:hover {
    gap: 0.75rem;
}

.project-link svg {
    transition: transform var(--transition-speed) var(--transition-ease);
}

.project-link:hover svg {
    transform: translate(2px, -2px);
}

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

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-text {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.contact-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    text-decoration: none;
    transition: all var(--transition-speed) var(--transition-ease);
}

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

.contact-icon {
    width: 48px;
    height: 48px;
    background: rgba(0, 217, 255, 0.1);
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon svg {
    color: var(--color-primary);
}

.contact-info {
    flex: 1;
}

.contact-label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 0.25rem;
}

.contact-value {
    font-size: 1rem;
    color: var(--color-text);
    font-weight: 500;
}

/* ====================================
   Footer
   ==================================== */
.footer {
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

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

.footer-brand {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
}

.footer-text p {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.footer-affiliations {
    font-size: 0.875rem;
    margin-top: var(--spacing-md);
}

.footer-bottom {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

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

/* ====================================
   Responsive Design
   ==================================== */
@media (max-width: 768px) {
    .nav {
      background: rgba(10, 14, 39, 0.9);
      border-bottom: 1px solid var(--color-border);
    }

    .nav-container {
      padding: var(--spacing-sm) var(--spacing-lg);
    }

    /* Show brand on mobile */
    .nav-logo {
      display: inline-flex;
      align-items: center;
    }

    /* Ensure the header shows logo left and home button right even when menu hidden */
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .nav-toggle {
        display: none;
    }

    /* Hide the top nav list on mobile; bottom-tabs will be used */
    .nav-menu {
        display: none !important;
    }

    /* Prevent header overlap */
    .hero {
      padding-top: 80px;
    }

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

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

.scroll-indicator {
        display: none;
    }

    /* Bottom tabs visibility and safe-area space */
    .bottom-tabs { display: flex; }
    body { padding-bottom: calc(var(--bottom-nav-height) + env(safe-area-inset-bottom)); }

    .about-stats {
        grid-template-columns: 1fr;
    }

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

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

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

    .timeline {
        padding-left: 1rem;
    }

    .timeline-item {
        padding-left: var(--spacing-lg);
    }

@media (max-width: 480px) {
    :root {
        --spacing-3xl: 3rem;
    }

    .container {
        padding: 0 var(--spacing-md);
    }

    .hero-content {
        padding: var(--spacing-2xl) var(--spacing-md);
    }

    .section {
        padding: var(--spacing-2xl) 0;
    }
}

/* ====================================
   Bottom Tabs (mobile-style, visible by default) 
   ==================================== */
.bottom-tabs {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    height: var(--bottom-nav-height);
    background: rgba(10, 14, 39, 0.98);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--color-border);
    display: none; /* hidden by default; shown on mobile */
    justify-content: space-around;
    align-items: center;
    padding: 0 var(--spacing-sm);
    padding-bottom: env(safe-area-inset-bottom);
    box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.4);
    z-index: 1100;
}

.bottom-tabs .tab-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    color: var(--color-text-light);
    text-decoration: none;
    font-size: 0.75rem;
    line-height: 1;
}

.bottom-tabs .tab-link .tab-icon {
    width: 24px;
    height: 24px;
}

.bottom-tabs .tab-link:hover,
.bottom-tabs .tab-link.active {
    color: var(--color-primary);
    font-weight: 600;
}

/* ====================================
   Animations
   ==================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s var(--transition-ease) forwards;
}

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

/* Focus styles for accessibility */
a:focus,
button:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Selection color */
::selection {
    background: var(--color-primary);
    color: var(--color-bg);
}

/* Final mobile override to ensure bottom tabs render at <=768px */
@media (max-width: 768px) {
  .bottom-tabs { display: flex !important; }
  body { padding-bottom: calc(var(--bottom-nav-height) + env(safe-area-inset-bottom)); }
}