/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */

:root {
    /* Fonts */
    --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: 'Space Mono', 'Fira Code', monospace;
    
    /* Layout Constants */
    --max-width: 1200px;
    --header-height: 80px;
    --border-radius-sm: 8px;
    --border-radius-md: 16px;
    --border-radius-lg: 24px;
    
    /* Animations */
    --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: 0.15s ease;
}

/* Day Mode Variables (DBA theme: light, structured, steel & navy) */
body.day-mode {
    --bg-primary: hsl(210, 20%, 96%);
    --bg-secondary: hsl(0, 0%, 100%);
    --bg-tertiary: hsl(210, 15%, 90%);
    --text-primary: hsl(210, 30%, 12%);
    --text-secondary: hsl(210, 15%, 45%);
    --accent: hsl(215, 85%, 45%);
    --accent-rgb: 17, 85, 204;
    --accent-hover: hsl(215, 85%, 35%);
    --accent-gradient: linear-gradient(135deg, hsl(215, 85%, 45%) 0%, hsl(195, 85%, 40%) 100%);
    --border-color: hsl(210, 15%, 85%);
    --shadow-color: rgba(15, 45, 90, 0.08);
    --glow-color: rgba(15, 85, 204, 0.0);
    --grid-opacity: 0.06;
    
    --header-bg: rgba(255, 255, 255, 0.8);
    --card-hover-border: hsl(215, 85%, 70%);
}

/* Night Mode Variables (Full Stack theme: dark, electric, neon cyan & space slate) */
body.night-mode {
    --bg-primary: hsl(222, 25%, 8%);
    --bg-secondary: hsl(222, 25%, 12%);
    --bg-tertiary: hsl(222, 20%, 16%);
    --text-primary: hsl(210, 40%, 98%);
    --text-secondary: hsl(210, 15%, 70%);
    --accent: hsl(175, 100%, 45%);
    --accent-rgb: 0, 230, 207;
    --accent-hover: hsl(175, 100%, 35%);
    --accent-gradient: linear-gradient(135deg, hsl(175, 100%, 45%) 0%, hsl(205, 100%, 50%) 100%);
    --border-color: hsl(222, 20%, 18%);
    --shadow-color: rgba(0, 0, 0, 0.3);
    --glow-color: rgba(0, 230, 207, 0.15);
    --grid-opacity: 0.12;
    
    --header-bg: rgba(15, 23, 42, 0.8);
    --card-hover-border: hsl(175, 100%, 45%);
}

/* ==========================================================================
   RESET & BASICS
   ========================================================================== */

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

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

img, svg {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

button, input, textarea {
    font-family: inherit;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 5px;
    border: 2px solid var(--bg-primary);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent);
}

/* ==========================================================================
   BACKGROUND PATTERNS
   ========================================================================== */

.bg-pattern {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

.grid-pattern {
    background-image: 
        linear-gradient(to right, var(--text-primary) 1px, transparent 1px),
        linear-gradient(to bottom, var(--text-primary) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: var(--grid-opacity);
    transition: opacity var(--transition-slow);
    mask-image: radial-gradient(circle, black 40%, transparent 90%);
    -webkit-mask-image: radial-gradient(circle, black 40%, transparent 90%);
}

.blob-pattern-1 {
    width: 600px;
    height: 600px;
    background: var(--accent);
    filter: blur(140px);
    opacity: 0.05;
    top: -200px;
    right: -100px;
    border-radius: 50%;
    transition: background var(--transition-slow), opacity var(--transition-slow);
}

.blob-pattern-2 {
    width: 500px;
    height: 500px;
    background: var(--accent);
    filter: blur(120px);
    opacity: 0.04;
    bottom: -100px;
    left: -100px;
    border-radius: 50%;
    transition: background var(--transition-slow), opacity var(--transition-slow);
}

body.night-mode .blob-pattern-1,
body.night-mode .blob-pattern-2 {
    opacity: 0.12; /* Slightly more glow in dark mode */
}

/* ==========================================================================
   TYPOGRAPHY & UTILITIES
   ========================================================================== */

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section-padding {
    padding: 120px 0;
}

.highlight {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 800;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-subtitle {
    font-family: var(--font-mono);
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    display: inline-block;
    margin-bottom: 8px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.section-underline {
    width: 60px;
    height: 4px;
    background: var(--accent-gradient);
    margin: 16px auto 0;
    border-radius: 2px;
}

/* Visibility classes */
body.day-mode .night-only {
    display: none !important;
}
body.night-mode .day-only {
    display: none !important;
}

/* ==========================================================================
   BUTTONS
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
    outline: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: #ffffff;
    box-shadow: 0 4px 14px var(--glow-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(var(--accent-rgb), 0.4);
}

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

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

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */

.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    transition: background-color var(--transition-slow), border-color var(--transition-normal);
}

.nav-container {
    max-width: var(--max-width);
    height: 100%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.05em;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

.logo-text {
    transition: opacity var(--transition-normal);
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    padding: 8px 0;
    transition: color var(--transition-normal);
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent-gradient);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-normal);
}

.nav-link:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

/* Theme Toggle Slider Switch */
.theme-toggle {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    width: 64px;
    height: 34px;
    border-radius: 17px;
    cursor: pointer;
    position: relative;
    outline: none;
    transition: background var(--transition-normal), border-color var(--transition-normal);
}

.toggle-track {
    width: 100%;
    height: 100%;
    display: block;
}

.toggle-thumb {
    position: absolute;
    top: 3px;
    left: 3px;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.15);
    transition: transform var(--transition-normal), background-color var(--transition-normal);
}

body.night-mode .toggle-thumb {
    transform: translateX(30px);
}

.icon-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon {
    width: 14px;
    height: 14px;
    color: var(--accent);
}

/* Mobile Nav Toggle Button */
.mobile-nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    outline: none;
}

.hamburger-line {
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    transition: all var(--transition-normal);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */

.hero-section {
    position: relative;
    min-height: calc(100vh - var(--header-height));
    margin-top: var(--header-height);
    display: flex;
    align-items: center;
    padding: 60px 0;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: center;
    width: 100%;
}

.badge-wrapper {
    margin-bottom: 24px;
}

.hero-badge {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent);
    background-color: rgba(var(--accent-rgb), 0.1);
    border: 1px solid rgba(var(--accent-rgb), 0.25);
    padding: 6px 14px;
    border-radius: 20px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 0 10px rgba(var(--accent-rgb), 0.05);
}

.badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    display: inline-block;
    animation: pulse 1.8s infinite;
}

@keyframes pulse {
    0% { transform: scale(0.9); opacity: 0.6; }
    50% { transform: scale(1.1); opacity: 1; }
    100% { transform: scale(0.9); opacity: 0.6; }
}

.hero-title {
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 1.35rem;
    color: var(--text-secondary);
    max-width: 580px;
    margin-bottom: 30px;
    animation: fadeIn 0.8s ease;
}

.hero-subtitle strong {
    color: var(--text-primary);
}

.hero-description {
    border-left: 3px solid var(--accent);
    padding-left: 20px;
    margin-bottom: 40px;
    max-width: 550px;
    position: relative;
    font-style: italic;
    color: var(--text-secondary);
}

.quote-symbol {
    position: absolute;
    top: -15px;
    left: 10px;
    font-size: 3rem;
    font-family: serif;
    opacity: 0.1;
    line-height: 1;
}

.hero-cta-group {
    display: flex;
    gap: 16px;
}

/* Hero Visual Graphic Area */
.hero-visual {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 1000px;
}

.visual-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    width: 100%;
    max-width: 440px;
    min-height: 380px;
    padding: 24px;
    box-shadow: 0 10px 30px var(--shadow-color), 0 0 40px var(--glow-color);
    position: relative;
    transform-style: preserve-3d;
    transition: transform var(--transition-slow), border-color var(--transition-normal), box-shadow var(--transition-slow);
}

.visual-card:hover {
    transform: translateY(-8px) rotateY(4deg) rotateX(2deg);
}

.visual-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
    height: 100%;
}

/* DBA SQL Console UI Mockup */
.db-console {
    background-color: #1a2233;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
    border: 1px solid rgba(255,255,255,0.05);
}

.console-header {
    background-color: #111827;
    padding: 10px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.dot.red { background-color: #ef4444; }
.dot.yellow { background-color: #f59e0b; }
.dot.green { background-color: #10b981; }

.console-title {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #9ca3af;
    margin-left: 10px;
}

.console-body {
    padding: 16px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #e5e7eb;
    line-height: 1.5;
}

.code-line {
    white-space: pre;
}

.indent-1 { padding-left: 16px; }

.keyword { color: #818cf8; font-weight: bold; }
.string { color: #34d399; }
.number { color: #f59e0b; }
.function { color: #60a5fa; }
.comment { color: #6b7280; font-style: italic; }

.console-divider {
    height: 1px;
    background-color: rgba(255,255,255,0.1);
    margin: 12px 0;
}

.console-output {
    color: #9ca3af;
}

.console-output.success {
    color: #34d399;
}

.console-output.highlight-text {
    color: #fbbf24;
    font-weight: bold;
}

.db-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.stat-card {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: var(--border-radius-sm);
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
}

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

/* DEV Code Editor Mockup */
.code-editor {
    background-color: #0f172a;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.05);
    box-shadow: 0 8px 24px rgba(0,0,0,0.25);
}

.editor-header {
    background-color: #020617;
    padding: 10px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.editor-title {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #94a3b8;
    margin-left: 10px;
}

.editor-body {
    padding: 16px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #f8fafc;
    line-height: 1.6;
}

.dev-preview {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    padding: 16px;
    position: relative;
    height: 120px;
    overflow: hidden;
}

.preview-dot-grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: radial-gradient(var(--text-secondary) 1px, transparent 1px);
    background-size: 10px 10px;
    opacity: 0.15;
}

.preview-element {
    position: relative;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    padding: 12px;
    max-width: 180px;
    z-index: 2;
}

.preview-tag {
    font-family: var(--font-mono);
    font-size: 0.55rem;
    color: var(--accent);
    font-weight: 700;
    display: block;
    margin-bottom: 6px;
}

.preview-bar {
    height: 6px;
    background-color: var(--bg-tertiary);
    border-radius: 3px;
    margin-bottom: 10px;
    overflow: hidden;
}

.bar-fill {
    height: 100%;
    background: var(--accent-gradient);
}

.preview-btn-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.preview-circle {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--accent);
}

.preview-line {
    height: 4px;
    width: 50px;
    background-color: var(--text-secondary);
    border-radius: 2px;
}

.card-glow {
    position: relative;
}

body.night-mode .card-glow::after {
    content: '';
    position: absolute;
    inset: -1px;
    background: var(--accent-gradient);
    border-radius: inherit;
    z-index: -1;
    filter: blur(10px);
    opacity: 0.3;
}

/* Scroll indicator mouse */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    opacity: 0.7;
    transition: opacity var(--transition-normal);
}

.scroll-indicator:hover {
    opacity: 1;
}

.mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--text-primary);
    border-radius: 12px;
    display: flex;
    justify-content: center;
    padding-top: 6px;
}

.wheel {
    width: 4px;
    height: 8px;
    background-color: var(--accent);
    border-radius: 2px;
    animation: scrollWheel 1.5s infinite;
}

.arrows {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.arrows span {
    display: block;
    width: 8px;
    height: 8px;
    border-bottom: 2px solid var(--text-primary);
    border-right: 2px solid var(--text-primary);
    transform: rotate(45deg);
    margin: -2px;
    animation: arrowDown 1.5s infinite;
}

.arrows span:nth-child(2) {
    animation-delay: 0.15s;
}

@keyframes scrollWheel {
    0% { transform: translateY(0); opacity: 1; }
    50% { transform: translateY(6px); opacity: 0.3; }
    100% { transform: translateY(0); opacity: 1; }
}

@keyframes arrowDown {
    0% { opacity: 0; transform: rotate(45deg) translate(-2px, -2px); }
    50% { opacity: 1; }
    100% { opacity: 0; transform: rotate(45deg) translate(2px, 2px); }
}

/* ==========================================================================
   ABOUT SECTION
   ========================================================================== */

.about-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 60px;
    align-items: center;
}

.about-text-container h3 {
    font-size: 1.75rem;
    margin-bottom: 20px;
}

.about-desc {
    color: var(--text-secondary);
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-top: 30px;
}

.about-feat-item {
    display: flex;
    gap: 16px;
}

.feat-icon-wrapper {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: var(--border-radius-sm);
    background-color: rgba(var(--accent-rgb), 0.1);
    border: 1px solid rgba(var(--accent-rgb), 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}

.feat-icon {
    width: 22px;
    height: 22px;
}

.feat-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.feat-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* About Card Visual (Premium layout block) */
.about-card-visual {
    position: relative;
    padding: 12px;
}

.about-card-visual::before {
    content: '';
    position: absolute;
    inset: 0;
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius-lg);
    z-index: 1;
}

.card-inner {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 40px;
    z-index: 2;
    position: relative;
    box-shadow: 0 10px 30px var(--shadow-color);
    transform: rotate(1deg);
    transition: transform var(--transition-normal);
}

.card-inner:hover {
    transform: rotate(0deg);
}

.quote-card {
    position: relative;
}

.quote-accent {
    font-size: 5rem;
    line-height: 1;
    font-family: serif;
    position: absolute;
    top: -30px;
    left: -20px;
    opacity: 0.15;
    color: var(--accent);
}

.quote-card blockquote {
    font-size: 1.2rem;
    font-weight: 500;
    line-height: 1.5;
    color: var(--text-primary);
    position: relative;
    z-index: 2;
    margin-bottom: 20px;
}

.quote-author {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 700;
}

/* ==========================================================================
   SKILLS SECTION
   ========================================================================== */

.skills-nav-container {
    display: flex;
    justify-content: center;
    margin-bottom: 40px;
}

.skills-tabs {
    display: flex;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 6px;
    border-radius: 30px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

.tab-btn {
    border: none;
    background: transparent;
    padding: 10px 24px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 20px;
    transition: all var(--transition-normal);
}

.tab-btn:hover {
    color: var(--text-primary);
}

.tab-btn.active {
    background: var(--accent-gradient);
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(var(--accent-rgb), 0.25);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
    transition: all 0.5s ease-in-out;
}

.skill-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 30px;
    box-shadow: 0 6px 20px var(--shadow-color), 0 0 20px var(--glow-color);
    position: relative;
    overflow: hidden;
    transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal), opacity 0.4s ease, scale 0.4s ease;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.skill-card::before {
    content: attr(data-level);
    position: absolute;
    top: 15px;
    right: 15px;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-secondary);
    background-color: var(--bg-tertiary);
    padding: 4px 10px;
    border-radius: 12px;
}

.skill-card:hover {
    transform: translateY(-5px);
    border-color: var(--card-hover-border);
    box-shadow: 0 10px 25px var(--shadow-color), 0 0 30px rgba(var(--accent-rgb), 0.15);
}

.skill-icon-header {
    display: flex;
    align-items: center;
    gap: 12px;
}

.skill-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--border-radius-sm);
    background-color: rgba(var(--accent-rgb), 0.1);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
}

.skill-icon svg {
    width: 20px;
    height: 20px;
}

.skill-category-badge {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 4px;
}

.dba-badge {
    background-color: rgba(30, 60, 114, 0.1);
    color: #1e3c72;
}

body.night-mode .dba-badge {
    background-color: rgba(96, 165, 250, 0.1);
    color: #60a5fa;
}

.dev-badge {
    background-color: rgba(16, 185, 129, 0.1);
    color: #10b981;
}

.skill-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-top: 4px;
}

.skill-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    flex-grow: 1;
}

.skill-progress {
    height: 6px;
    background-color: var(--bg-tertiary);
    border-radius: 3px;
    overflow: hidden;
    margin-top: 8px;
}

.skill-progress .fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 3px;
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */

.projects-filter-bar {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.filter-btn {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-normal);
}

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

.filter-btn.active {
    background-color: var(--text-primary);
    border-color: var(--text-primary);
    color: var(--bg-primary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(450px, 1fr));
    gap: 40px;
}

.project-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: 0 8px 24px var(--shadow-color);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-8px);
    border-color: var(--card-hover-border);
    box-shadow: 0 16px 40px var(--shadow-color), 0 0 30px var(--glow-color);
}

/* Custom CSS illustrated visual fallback instead of flat images */
.project-image-fallback {
    height: 220px;
    background-color: var(--bg-tertiary);
    border-bottom: 1px solid var(--border-color);
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

/* CSS UI Illustration */
.proj-ill {
    position: relative;
    width: 80%;
    height: 70%;
    border-radius: var(--border-radius-sm);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.ui-ill {
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.ill-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent);
}

.ill-line {
    height: 6px;
    background-color: var(--border-color);
    border-radius: 3px;
}

.fill-70 { width: 70%; }
.fill-40 { width: 40%; }

.ill-box-row {
    display: flex;
    gap: 10px;
    flex-grow: 1;
    align-items: flex-end;
}

.ill-box {
    flex: 1;
    height: 40px;
    border-radius: 4px;
    background-color: rgba(var(--accent-rgb), 0.05);
    border: 1px dashed rgba(var(--accent-rgb), 0.3);
}

/* CSS DB Node Illustration */
.db-ill {
    background-color: transparent;
    border: none;
    align-items: center;
    justify-content: center;
}

.node-main {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--accent-gradient);
    z-index: 2;
    box-shadow: 0 0 20px rgba(var(--accent-rgb), 0.3);
}

.node-connection {
    position: absolute;
    width: 140px;
    height: 2px;
    background-color: var(--border-color);
    z-index: 1;
}

.node-sub {
    position: absolute;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: var(--bg-secondary);
    border: 2px solid var(--accent);
    z-index: 2;
}

.left-node { left: 40px; }
.right-node { right: 40px; }

/* CSS Schema Diagram Illustration */
.schema-ill {
    background-color: transparent;
    border: none;
}

.table-box {
    position: absolute;
    width: 80px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    overflow: hidden;
}

.box-1 { left: 40px; top: 30px; }
.box-2 { right: 40px; bottom: 30px; }

.table-header {
    height: 16px;
    background-color: var(--accent);
    opacity: 0.8;
}

.table-row {
    height: 8px;
    margin: 8px;
    background-color: var(--border-color);
    border-radius: 2px;
}

.svg-link-line {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

/* CSS Cache stack illustration */
.cache-ill {
    background-color: transparent;
    border: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.stack-level {
    width: 120px;
    height: 22px;
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 4px;
    transition: transform var(--transition-normal);
}

.top-level {
    border-color: var(--accent);
    background-color: rgba(var(--accent-rgb), 0.05);
}

.cache-ill:hover .top-level { transform: translateY(-4px); }
.cache-ill:hover .low-level { transform: translateY(4px); }

/* Project contents styling */
.project-content {
    padding: 30px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    flex-grow: 1;
}

.project-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.p-tag {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-secondary);
    background-color: var(--bg-tertiary);
    padding: 4px 10px;
    border-radius: 4px;
}

.project-content h3 {
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.25;
}

.project-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
    flex-grow: 1;
}

.project-links {
    display: flex;
    gap: 16px;
    margin-top: 8px;
}

.p-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: color var(--transition-normal);
}

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

.link-icon {
    width: 16px;
    height: 16px;
}

/* ==========================================================================
   EXPERIENCE TIMELINE
   ========================================================================== */

.timeline-section {
    position: relative;
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 8px;
    top: 10px;
    bottom: 10px;
    width: 2px;
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
}

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

.timeline-dot {
    position: absolute;
    left: -32px;
    top: 6px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background-color: var(--bg-primary);
    border: 3px solid var(--accent);
    z-index: 2;
    transition: background-color var(--transition-normal), transform var(--transition-normal);
}

.timeline-item:hover .timeline-dot {
    transform: scale(1.2);
    background-color: var(--accent);
}

.timeline-date {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 6px;
}

.timeline-content {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 24px;
    box-shadow: 0 4px 16px var(--shadow-color);
    transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.timeline-item:hover .timeline-content {
    border-color: var(--card-hover-border);
    box-shadow: 0 8px 24px var(--shadow-color);
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.timeline-org {
    display: inline-block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.timeline-content p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */

.contact-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-info h3 {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1.2;
}

.contact-info p {
    color: var(--text-secondary);
    font-size: 1.05rem;
}

.info-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.info-item {
    display: flex;
    gap: 16px;
    align-items: center;
}

.info-icon {
    width: 24px;
    height: 24px;
    color: var(--accent);
    flex-shrink: 0;
}

.info-item h4 {
    font-size: 0.8rem;
    font-family: var(--font-mono);
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 2px;
}

.info-item a {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: color var(--transition-normal);
}

.info-item a:hover {
    color: var(--accent);
}

/* Contact Form UI */
.contact-form-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 40px;
    box-shadow: 0 10px 30px var(--shadow-color);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.form-row {
    position: relative;
    width: 100%;
}

.form-group {
    position: relative;
    width: 100%;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    font-size: 0.95rem;
    outline: none;
    transition: all var(--transition-normal);
}

.form-group textarea {
    resize: none;
}

/* Floating labels effect */
.form-group label {
    position: absolute;
    left: 16px;
    top: 15px;
    color: var(--text-secondary);
    font-size: 0.95rem;
    pointer-events: none;
    transition: all var(--transition-normal);
    transform-origin: left top;
}

.form-group textarea ~ label {
    top: 15px;
}

/* Label positions during focus and content presence */
.form-group input:focus ~ label,
.form-group input:not(:placeholder-shown) ~ label,
.form-group textarea:focus ~ label,
.form-group textarea:not(:placeholder-shown) ~ label {
    transform: translateY(-26px) scale(0.8);
    color: var(--accent);
    font-weight: 600;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.15);
    background-color: var(--bg-secondary);
}

/* Custom error message styling */
.error-msg {
    display: none;
    color: #ef4444;
    font-size: 0.75rem;
    margin-top: 4px;
    font-weight: 500;
}

.form-group.invalid input,
.form-group.invalid textarea {
    border-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.02);
}

.form-group.invalid .error-msg {
    display: block;
}

/* Form Submission Button */
.btn-submit {
    width: 100%;
    background: var(--accent-gradient);
    color: #ffffff;
    font-weight: 700;
    box-shadow: 0 4px 14px var(--glow-color);
    display: flex;
    gap: 12px;
    position: relative;
    overflow: hidden;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(var(--accent-rgb), 0.4);
}

.btn-submit .spinner {
    display: none;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #ffffff;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.btn-submit.loading .btn-text {
    opacity: 0.7;
}

.btn-submit.loading .spinner {
    display: block;
}

/* Form Submit Status message */
.form-status-msg {
    text-align: center;
    font-size: 0.9rem;
    font-weight: 600;
    margin-top: 10px;
    display: none;
    padding: 10px;
    border-radius: var(--border-radius-sm);
}

.form-status-msg.success {
    display: block;
    color: #10b981;
    background-color: rgba(16, 185, 129, 0.08);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.form-status-msg.error {
    display: block;
    color: #ef4444;
    background-color: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.footer {
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    padding: 40px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
    transition: background-color var(--transition-slow), border-color var(--transition-normal);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-socials {
    display: flex;
    gap: 16px;
}

.footer-icon {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
    transition: color var(--transition-normal), transform var(--transition-normal);
}

.footer-socials a:hover .footer-icon {
    color: var(--accent);
    transform: translateY(-2px);
}

/* ==========================================================================
   RESPONSIVE DESIGN (MEDIA QUERIES)
   ========================================================================== */

@media (max-width: 1024px) {
    .hero-title {
        font-size: 3.2rem;
    }
    .hero-grid {
        grid-template-columns: 1.1fr 0.9fr;
        gap: 40px;
    }
    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }
    .about-card-visual {
        max-width: 500px;
        margin: 0 auto;
    }
}

@media (max-width: 768px) {
    /* Header menu mobile layout */
    .mobile-nav-toggle {
        display: flex;
        z-index: 102;
    }
    
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background-color: var(--bg-secondary);
        border-left: 1px solid var(--border-color);
        box-shadow: -10px 0 30px rgba(0,0,0,0.15);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        z-index: 101;
        transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    /* Hamburger to X animation */
    .mobile-nav-toggle.active .hamburger-line:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    .mobile-nav-toggle.active .hamburger-line:nth-child(2) {
        opacity: 0;
    }
    .mobile-nav-toggle.active .hamburger-line:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 50px;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-description {
        border-left: none;
        border-top: 2px solid var(--accent);
        padding-left: 0;
        padding-top: 15px;
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-cta-group {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1; /* Display graphic on top on mobile devices */
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
        max-width: 550px;
        margin: 0 auto;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.5rem;
    }
    .hero-cta-group {
        flex-direction: column;
        width: 100%;
    }
    .btn {
        width: 100%;
    }
    .contact-form-container {
        padding: 24px;
    }
    .timeline {
        padding-left: 24px;
    }
    .timeline-dot {
        left: -24px;
        width: 14px;
        height: 14px;
    }
    .timeline::before {
        left: 6px;
    }
}