/* ==========================================================================
   Umit Kavala Executive Portfolio - Master Style Sheet
   Aesthetic: Premium Executive Dark/Light Glassmorphism with Vibrant Accents
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Variables & Design Tokens
   -------------------------------------------------------------------------- */
:root {
    /* Fonts */
    --font-heading: 'Plus Jakarta Sans', 'Inter', -apple-system, sans-serif;
    --font-body: 'Inter', -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Theme Palette - Dark (Default) */
    --bg-primary: #0b0f19;
    --bg-secondary: #111827;
    --bg-tertiary: #1f2937;
    
    --card-bg: rgba(17, 24, 39, 0.65);
    --card-border: rgba(255, 255, 255, 0.08);
    --card-hover-border: rgba(56, 189, 248, 0.4);
    --glass-blur: blur(16px);

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    /* Accent Gradients & Colors */
    --accent-gold: #f59e0b;
    --accent-cyan: #38bdf8;
    --accent-purple: #818cf8;
    --accent-green: #10b981;

    --gradient-primary: linear-gradient(135deg, #38bdf8 0%, #818cf8 50%, #f59e0b 100%);
    --gradient-text: linear-gradient(135deg, #f8fafc 30%, #38bdf8 70%, #818cf8 100%);
    --gradient-card: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.01) 100%);

    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 30px rgba(56, 189, 248, 0.15);

    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 24px;
    --radius-full: 9999px;

    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

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

.container {
    width: 100%;
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: 6rem 0;
    position: relative;
    z-index: 1;
}

/* --------------------------------------------------------------------------
   Dynamic Background Glows
   -------------------------------------------------------------------------- */
.bg-glow {
    position: fixed;
    border-radius: 50%;
    filter: blur(140px);
    pointer-events: none;
    z-index: 0;
    opacity: 0.35;
    transition: opacity var(--transition-normal);
}

[data-theme="light"] .bg-glow {
    opacity: 0.18;
}

.bg-glow-1 {
    width: 500px;
    height: 500px;
    background: #38bdf8;
    top: -100px;
    left: -100px;
}

.bg-glow-2 {
    width: 600px;
    height: 600px;
    background: #818cf8;
    top: 40%;
    right: -200px;
}

.bg-glow-3 {
    width: 450px;
    height: 450px;
    background: #f59e0b;
    bottom: -100px;
    left: 20%;
}

/* --------------------------------------------------------------------------
   Glassmorphism Panel System
   -------------------------------------------------------------------------- */
.glass-panel {
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

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

/* --------------------------------------------------------------------------
   Typography & Helper Utilities
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.25;
    color: var(--text-primary);
}

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

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

.section-header {
    margin-bottom: 3.5rem;
}

.section-subtitle {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--accent-cyan);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.5rem;
}

.section-title {
    font-size: 2.5rem;
    letter-spacing: -0.02em;
    margin-bottom: 0.75rem;
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 650px;
    margin: 0 auto;
}

.section-divider {
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    margin: 1.25rem auto 0;
}

/* --------------------------------------------------------------------------
   Buttons & Badges
   -------------------------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    padding: 0.85rem 1.6rem;
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    text-decoration: none;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all var(--transition-fast);
}

.btn-primary {
    background: var(--gradient-primary);
    color: #0f172a;
    box-shadow: 0 4px 14px rgba(56, 189, 248, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(56, 189, 248, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-primary);
    border-color: var(--card-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--accent-cyan);
    border-color: rgba(56, 189, 248, 0.4);
}

.btn-outline:hover {
    background: rgba(56, 189, 248, 0.1);
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

.badge-primary, .badge-secondary, .badge-ghost {
    display: inline-block;
    padding: 0.35rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: var(--radius-full);
}

.badge-primary {
    background: rgba(56, 189, 248, 0.15);
    color: var(--accent-cyan);
    border: 1px solid rgba(56, 189, 248, 0.3);
}

.badge-secondary {
    background: rgba(245, 158, 11, 0.15);
    color: var(--accent-gold);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-ghost {
    background: rgba(129, 140, 248, 0.15);
    color: var(--accent-purple);
    border: 1px solid rgba(129, 140, 248, 0.3);
}

/* --------------------------------------------------------------------------
   Header & Navbar
   -------------------------------------------------------------------------- */
.navbar-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1.25rem 0;
    transition: all var(--transition-normal);
}

.navbar-header.scrolled {
    padding: 0.85rem 0;
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--card-border);
    box-shadow: var(--shadow-sm);
}

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

.brand-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text-primary);
}

.logo-avatar {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--accent-cyan);
    box-shadow: 0 0 12px rgba(56, 189, 248, 0.35);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.brand-logo:hover .logo-avatar {
    transform: scale(1.08);
    box-shadow: 0 0 16px rgba(56, 189, 248, 0.6);
}

.logo-text {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.25rem;
}

.accent-dot {
    color: var(--accent-cyan);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

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

.nav-link:hover, .nav-link.active {
    color: var(--accent-cyan);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent-cyan);
    border-radius: var(--radius-full);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle-btn {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--accent-cyan);
}

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

.mobile-nav-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
    width: 30px;
    padding: 0;
}

.mobile-nav-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.mobile-nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.mobile-nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero-section {
    padding-top: 10rem;
    padding-bottom: 5rem;
}

.hero-container {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 3.5rem;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.4rem 1rem;
    border-radius: var(--radius-full);
    background: rgba(56, 189, 248, 0.1);
    border: 1px solid rgba(56, 189, 248, 0.25);
    color: var(--accent-cyan);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent-green);
    box-shadow: 0 0 10px var(--accent-green);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
    70% { transform: scale(1); box-shadow: 0 0 0 10px rgba(16, 185, 129, 0); }
    100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
    font-size: 3.25rem;
    letter-spacing: -0.03em;
    margin-bottom: 1.25rem;
    line-height: 1.15;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 2.25rem;
    line-height: 1.7;
}

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

.hero-quick-info {
    display: flex;
    flex-wrap: wrap;
    gap: 1.75rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--card-border);
}

.info-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.info-item svg {
    color: var(--accent-cyan);
}

/* Hero Code Visual Card */
.executive-card {
    padding: 0;
    overflow: hidden;
    border-radius: var(--radius-lg);
}

.card-header-bar {
    background: rgba(0, 0, 0, 0.3);
    padding: 0.75rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-bottom: 1px solid var(--card-border);
}

.window-dot {
    width: 11px;
    height: 11px;
    border-radius: 50%;
}
.window-dot.red { background-color: #ef4444; }
.window-dot.yellow { background-color: #f59e0b; }
.window-dot.green { background-color: #10b981; }

.window-title {
    margin-left: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.card-body {
    padding: 1.5rem;
}

.code-block {
    font-family: var(--font-mono);
    font-size: 0.88rem;
    line-height: 1.7;
    color: var(--text-primary);
}

.code-keyword { color: #f472b6; }
.code-var { color: #38bdf8; }
.code-string { color: #34d399; }
.code-num { color: #fbbf24; }

.card-footer-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--card-border);
    padding: 1rem;
    text-align: center;
}

.mini-stat {
    display: flex;
    flex-direction: column;
}

.stat-val {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.15rem;
    color: var(--accent-cyan);
}

.stat-lbl {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   About Section
   -------------------------------------------------------------------------- */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.75rem;
}

.about-card {
    padding: 2rem;
}

.about-icon {
    width: 54px;
    height: 54px;
    border-radius: var(--radius-md);
    background: rgba(56, 189, 248, 0.1);
    color: var(--accent-cyan);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
    border: 1px solid rgba(56, 189, 248, 0.2);
}

.about-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.about-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --------------------------------------------------------------------------
   Impact & Key Performance Counters Section
   -------------------------------------------------------------------------- */
.impact-section {
    background: rgba(0, 0, 0, 0.15);
}

.impact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.75rem;
}

.impact-card {
    padding: 2.25rem 2rem;
    position: relative;
    overflow: hidden;
}

.impact-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-primary);
}

.impact-number {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 3.25rem;
    line-height: 1;
    color: var(--accent-cyan);
    margin-bottom: 0.75rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.impact-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.impact-desc {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.55;
}

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

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 7px;
    width: 2px;
    height: 100%;
    background: var(--card-border);
}

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

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

.timeline-dot {
    position: absolute;
    left: -2rem;
    top: 1.5rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 3px solid var(--accent-cyan);
    transform: translateX(-50%);
    box-shadow: 0 0 10px rgba(56, 189, 248, 0.5);
    z-index: 2;
}

.timeline-content {
    padding: 2.25rem;
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.role-title {
    font-size: 1.35rem;
    color: var(--text-primary);
}

.company-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-cyan);
    margin-top: 0.2rem;
}

.role-period {
    align-self: flex-start;
}

.role-highlights {
    list-style: none;
    margin-bottom: 1.5rem;
}

.role-highlights li {
    position: relative;
    padding-left: 1.5rem;
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.role-highlights li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent-cyan);
    font-weight: bold;
}

.role-tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--card-border);
}

.tag {
    padding: 0.25rem 0.75rem;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    border: 1px solid var(--card-border);
}

/* --------------------------------------------------------------------------
   Projects & Case Studies Section
   -------------------------------------------------------------------------- */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.project-card {
    padding: 2.25rem;
    display: flex;
    flex-direction: column;
}

.project-tag {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--accent-gold);
    text-transform: uppercase;
    margin-bottom: 0.6rem;
}

.project-title {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
}

.project-summary {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.project-metrics {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding: 0.85rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-sm);
}

.p-metric {
    display: flex;
    flex-direction: column;
}

.p-metric-val {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--accent-cyan);
}

.p-metric-lbl {
    font-size: 0.72rem;
    color: var(--text-muted);
}

.open-modal-btn {
    align-self: flex-start;
}

/* --------------------------------------------------------------------------
   Skills Matrix Section
   -------------------------------------------------------------------------- */
.skills-filter-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-bottom: 2.5rem;
}

.skills-tab {
    padding: 0.6rem 1.25rem;
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.skills-tab:hover, .skills-tab.active {
    background: var(--gradient-primary);
    color: #0f172a;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.25);
}

.skills-matrix {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.75rem;
}

.skill-category-block {
    background: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 1.75rem;
    transition: all var(--transition-normal);
}

.skill-category-block.hidden {
    display: none;
}

.category-title {
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 1.25rem;
    color: var(--accent-cyan);
}

.skill-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.skill-pill {
    padding: 0.4rem 0.85rem;
    font-size: 0.85rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
}

.skill-pill.highlight-pill {
    background: rgba(245, 158, 11, 0.1);
    border-color: rgba(245, 158, 11, 0.3);
    color: var(--accent-gold);
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   Education & Certifications Section
   -------------------------------------------------------------------------- */
.education-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
}

.column-title {
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 1.5rem;
}

.edu-card {
    padding: 1.75rem;
    margin-bottom: 1.25rem;
    position: relative;
}

.highlight-border {
    border-color: rgba(245, 158, 11, 0.4);
}

.edu-badge-rank {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 0.72rem;
    font-family: var(--font-mono);
    font-weight: 700;
    padding: 0.2rem 0.6rem;
    background: rgba(245, 158, 11, 0.15);
    color: var(--accent-gold);
    border-radius: var(--radius-full);
}

.edu-degree {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.edu-institution {
    font-size: 0.95rem;
    color: var(--accent-cyan);
    margin-bottom: 0.5rem;
}

.edu-gpa {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

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

.cert-card {
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.cert-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-mono);
    font-weight: 800;
    font-size: 0.75rem;
    flex-shrink: 0;
}

.cert-icon.aws { background: rgba(245, 158, 11, 0.15); color: #f59e0b; }
.cert-icon.itil { background: rgba(56, 189, 248, 0.15); color: #38bdf8; }
.cert-icon.agile { background: rgba(129, 140, 248, 0.15); color: #818cf8; }
.cert-icon.psm { background: rgba(16, 185, 129, 0.15); color: #10b981; }
.cert-icon.ms { background: rgba(59, 130, 246, 0.15); color: #3b82f6; }
.cert-icon.sec { background: rgba(239, 68, 68, 0.15); color: #ef4444; }

.cert-name {
    font-size: 0.88rem;
    font-weight: 600;
    line-height: 1.3;
}

.cert-issuer {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   Contact Section
   -------------------------------------------------------------------------- */
.contact-box {
    padding: 4rem 2rem;
    max-width: 850px;
    margin: 0 auto;
}

.contact-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 1rem auto 2.5rem;
}

.contact-details {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.contact-detail-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.contact-detail-item:hover {
    color: var(--accent-cyan);
}

.contact-detail-item svg {
    color: var(--accent-cyan);
}

.contact-social-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    padding: 2.5rem 0;
    border-top: 1px solid var(--card-border);
    background: var(--bg-primary);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-logo {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.1rem;
    margin-right: 1.5rem;
}

.footer-copy {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color var(--transition-fast);
}

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

/* --------------------------------------------------------------------------
   Modal Window Component
   -------------------------------------------------------------------------- */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(8px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-container {
    max-width: 650px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    padding: 2.5rem;
    position: relative;
    transform: translateY(20px);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal-container {
    transform: translateY(0);
}

.modal-close {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.8rem;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-header h2 {
    font-size: 1.75rem;
    margin-top: 0.5rem;
    margin-bottom: 1.5rem;
}

.modal-body h4 {
    color: var(--accent-cyan);
    font-size: 1.1rem;
    margin-top: 1.25rem;
    margin-bottom: 0.5rem;
}

.modal-body p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.modal-body ul {
    margin-top: 0.5rem;
    padding-left: 1.25rem;
    color: var(--text-secondary);
}

.modal-body li {
    margin-bottom: 0.4rem;
}

/* --------------------------------------------------------------------------
   Responsive Media Queries
   -------------------------------------------------------------------------- */
/* --------------------------------------------------------------------------
   Responsive Media Queries & Mobile View Optimization
   -------------------------------------------------------------------------- */
@media (max-width: 992px) {
    .hero-section {
        padding-top: 8rem;
        padding-bottom: 3.5rem;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .hero-title {
        font-size: 2.6rem;
    }

    .education-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .nav-menu {
        position: fixed;
        top: 68px;
        left: 0;
        width: 100%;
        height: calc(100vh - 68px);
        background: rgba(11, 15, 25, 0.96);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border-bottom: 1px solid var(--card-border);
        flex-direction: column;
        justify-content: flex-start;
        padding: 3rem 1.5rem;
        gap: 1.75rem;
        transform: translateY(-150%);
        transition: transform var(--transition-normal);
        z-index: 999;
        overflow-y: auto;
    }

    .nav-menu.active {
        transform: translateY(0);
    }

    .nav-link {
        font-size: 1.15rem;
    }

    .mobile-nav-toggle {
        display: flex;
    }

    .ai-hero-banner {
        grid-template-columns: 1fr;
        padding: 2rem;
    }
}

@media (max-width: 640px) {
    .section {
        padding: 4rem 0;
    }

    .hero-section {
        padding-top: 7rem;
    }

    .hero-title {
        font-size: 2.1rem;
    }

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

    .section-title {
        font-size: 1.85rem;
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

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

    .impact-grid, .projects-grid, .skills-matrix, .antigravity-grid, .ai-grid {
        grid-template-columns: 1fr;
    }

    .impact-number {
        font-size: 2.6rem;
    }

    .timeline {
        padding-left: 1rem;
    }

    .timeline::before {
        left: 3px;
    }

    .timeline-dot {
        left: -1rem;
        width: 14px;
        height: 14px;
    }

    .timeline-content {
        padding: 1.5rem 1.15rem;
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .role-title {
        font-size: 1.2rem;
    }

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

    .contact-box {
        padding: 2.5rem 1.25rem;
    }

    .contact-details {
        flex-direction: column;
        align-items: center;
        gap: 1.25rem;
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
        gap: 1.25rem;
    }

    .modal-container {
        padding: 1.75rem 1.25rem;
        width: 94%;
        max-height: 85vh;
    }

    .code-block {
        font-size: 0.78rem;
        overflow-x: auto;
    }
}

@media (max-width: 400px) {
    .hero-title {
        font-size: 1.85rem;
    }

    .brand-logo .logo-text {
        font-size: 1.1rem;
    }

    .logo-avatar {
        width: 36px;
        height: 36px;
    }
}

/* --------------------------------------------------------------------------
   AI Engineering Adoption Section Styles
   -------------------------------------------------------------------------- */
.ai-engineering-section {
    background: linear-gradient(180deg, rgba(11, 15, 25, 0.4) 0%, rgba(17, 24, 39, 0.8) 100%);
    position: relative;
}

.ai-hero-banner {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 2.5rem;
    padding: 3rem;
    margin-bottom: 2.5rem;
    align-items: center;
    border: 1px solid rgba(56, 189, 248, 0.25);
    background: linear-gradient(135deg, rgba(17, 24, 39, 0.8) 0%, rgba(31, 41, 55, 0.5) 100%);
    box-shadow: 0 0 35px rgba(56, 189, 248, 0.1);
}

.ai-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.35rem 0.9rem;
    border-radius: var(--radius-full);
    background: rgba(245, 158, 11, 0.12);
    border: 1px solid rgba(245, 158, 11, 0.3);
    color: var(--accent-gold);
    font-size: 0.78rem;
    font-weight: 700;
    font-family: var(--font-mono);
    margin-bottom: 1.25rem;
}

.ai-badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent-gold);
    box-shadow: 0 0 10px var(--accent-gold);
}

.ai-banner-content h3 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
    line-height: 1.25;
}

.ai-banner-content p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 1.75rem;
    line-height: 1.65;
}

.ai-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.ai-pill {
    padding: 0.4rem 0.9rem;
    font-size: 0.82rem;
    font-family: var(--font-mono);
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--card-border);
    color: var(--text-primary);
}

.ai-pill.highlight-pill {
    background: rgba(56, 189, 248, 0.15);
    border-color: rgba(56, 189, 248, 0.4);
    color: var(--accent-cyan);
    font-weight: 600;
}

.ai-pipeline-visual {
    background: rgba(11, 15, 25, 0.7);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 1.5rem;
}

.pipeline-header {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-cyan);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--card-border);
}

.pipeline-steps {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.p-step {
    display: flex;
    align-items: flex-start;
    gap: 0.85rem;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-sm);
    transition: border-color var(--transition-fast);
}

.p-step.active-step {
    border-color: var(--accent-cyan);
    background: rgba(56, 189, 248, 0.08);
}

.p-step.success-step {
    border-color: var(--accent-green);
    background: rgba(16, 185, 129, 0.08);
}

.step-num {
    font-family: var(--font-mono);
    font-weight: 800;
    font-size: 0.85rem;
    color: var(--accent-cyan);
    background: rgba(56, 189, 248, 0.15);
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.step-text strong {
    display: block;
    font-size: 0.88rem;
    color: var(--text-primary);
}

.step-text span {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.p-step-arrow {
    text-align: center;
    color: var(--accent-cyan);
    font-size: 0.9rem;
    line-height: 1;
}

.ai-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.75rem;
}

.ai-card {
    padding: 1.85rem;
}

.ai-card-icon {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-md);
    background: rgba(245, 158, 11, 0.1);
    color: var(--accent-gold);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
    border: 1px solid rgba(245, 158, 11, 0.25);
}

.ai-card h4 {
    font-size: 1.15rem;
    margin-bottom: 0.6rem;
}

.ai-card p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

@media (max-width: 992px) {
    .ai-hero-banner {
        grid-template-columns: 1fr;
        padding: 2rem;
    }
}

/* --------------------------------------------------------------------------
   KVKK / GDPR Notice Style
   -------------------------------------------------------------------------- */
.kvkk-notice {
    margin-top: 2rem;
    padding: 0.85rem 1.25rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.82rem;
    color: var(--text-muted);
    max-width: 680px;
    text-align: left;
}

.kvkk-notice svg {
    color: var(--accent-cyan);
    flex-shrink: 0;
}