/* ===================================
   CSS Variables & Root Styles
   =================================== */
:root {
    /* Light Theme Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #1a1a1a;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    --accent-primary: #3b82f6;
    --accent-secondary: #2563eb;
    --accent-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    --accent-primary: #60a5fa;
    --accent-secondary: #3b82f6;
    --border-color: #334155;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.4);
}

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

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Theme Toggle Button
   =================================== */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    color: var(--text-primary);
}

.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: block;
}

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

/* ===================================
   Navigation
   =================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 999;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.nav.scrolled {
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.9);
}

[data-theme="dark"] .nav.scrolled {
    background: rgba(15, 23, 42, 0.9);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
    align-items: center;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: width var(--transition-base);
}

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

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

.nav-link-cta {
    background: var(--accent-gradient);
    color: white;
    padding: 0.5rem 1.25rem;
    border-radius: 25px;
    transition: all var(--transition-base);
}

.nav-link-cta::after {
    display: none;
}

.nav-link-cta:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    color: white;
}

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: all var(--transition-base);
    border-radius: 2px;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 70px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    background-image: url('../images/hero-background-original.webp');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.hero-gradient {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.9) 0%, rgba(118, 75, 162, 0.9) 100%);
    opacity: 0.95;
}

[data-theme="dark"] .hero-gradient {
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.85) 0%, rgba(30, 41, 59, 0.85) 100%);
    opacity: 0.95;
}

.hero-content {
    text-align: center;
    animation: fadeInUp 1s ease;
}

.hero-title {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.hero-greeting {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    color: white;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-role {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 6vw, 5rem);
    font-weight: 900;
    color: white;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-description {
    max-width: 700px;
    margin: var(--spacing-md) auto;
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: rgba(255, 255, 255, 0.95);
    line-height: 1.8;
    animation: fadeInUp 1s ease 0.6s both;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-top: var(--spacing-md);
    animation: fadeInUp 1s ease 0.8s both;
    flex-wrap: wrap;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    animation: fadeIn 1s ease 1s both;
}

.scroll-mouse {
    width: 30px;
    height: 50px;
    border: 2px solid rgba(255, 255, 255, 0.6);
    border-radius: 20px;
    position: relative;
}

.scroll-wheel {
    width: 4px;
    height: 10px;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 2px;
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollDown 2s infinite;
}

@keyframes scrollDown {
    0%, 100% {
        top: 10px;
        opacity: 1;
    }
    50% {
        top: 25px;
        opacity: 0.5;
    }
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 50px;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    font-family: var(--font-primary);
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: var(--bg-secondary);
    transform: translateY(-3px);
}

.btn-submit {
    width: 100%;
    position: relative;
}

.btn-submit.loading .btn-text {
    opacity: 0;
}

.btn-submit.loading .btn-loader {
    opacity: 1;
}

.btn-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    opacity: 0;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

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

section:nth-child(even) {
    background: var(--bg-secondary);
}

section:nth-child(odd) {
    background: var(--bg-primary);
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-family: var(--font-heading);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

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

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

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

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

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

.about-intro {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-details {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.about-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.highlight-item {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--bg-primary);
    border-radius: 15px;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.highlight-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.highlight-number {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.highlight-label {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===================================
   Services Section
   =================================== */
.services {
    position: relative;
}

.services::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.services .container {
    position: relative;
    z-index: 1;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.service-card {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: 15px;
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-primary);
}

.service-icon {
    width: 70px;
    height: 70px;
    background: var(--accent-gradient);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-base);
}

.service-card:hover .service-icon {
    transform: scale(1.1) rotate(5deg);
}

.service-icon svg {
    color: white;
}

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

.service-description {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===================================
   Portfolio Section
   =================================== */
.portfolio {
    background: var(--bg-secondary);
    position: relative;
}

.portfolio::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

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

.portfolio-card {
    background: var(--bg-primary);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

.portfolio-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.portfolio-image {
    background-position: center top !important;
    background-size: cover !important;
    height: 250px;
    background: var(--accent-gradient);
    position: relative;
    overflow: hidden;
}

.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.portfolio-card:hover .portfolio-overlay {
    opacity: 1;
}

.portfolio-links {
    display: flex;
    gap: var(--spacing-sm);
}

.portfolio-link {
    padding: 0.75rem 1.5rem;
    background: white;
    color: #1a1a1a;
    text-decoration: none;
    border-radius: 25px;
    font-weight: 600;
    transition: all var(--transition-fast);
}

.portfolio-link:hover {
    transform: scale(1.05);
}

.portfolio-link-disabled {
    padding: 0.75rem 1.5rem;
    background: rgba(255, 255, 255, 0.3);
    color: white;
    border-radius: 25px;
    font-weight: 600;
}

.portfolio-content {
    padding: var(--spacing-md);
}

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

.portfolio-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-sm);
}

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

.tag {
    padding: 0.375rem 0.875rem;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
}

/* ===================================
   Skills Section
   =================================== */
.skills {
    position: relative;
    overflow: hidden;
}

.skills::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(30deg, var(--border-color) 12%, transparent 12.5%, transparent 87%, var(--border-color) 87.5%, var(--border-color)),
        linear-gradient(150deg, var(--border-color) 12%, transparent 12.5%, transparent 87%, var(--border-color) 87.5%, var(--border-color)),
        linear-gradient(30deg, var(--border-color) 12%, transparent 12.5%, transparent 87%, var(--border-color) 87.5%, var(--border-color)),
        linear-gradient(150deg, var(--border-color) 12%, transparent 12.5%, transparent 87%, var(--border-color) 87.5%, var(--border-color));
    background-size: 80px 140px;
    background-position: 0 0, 0 0, 40px 70px, 40px 70px;
    opacity: 0.03;
    pointer-events: none;
}

.skills .container {
    position: relative;
    z-index: 1;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-lg);
}

.skills-category {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: 15px;
    border: 1px solid var(--border-color);
}

.skills-category-title {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.skills-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.skill-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.skill-name {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 1rem;
}

.skill-bar {
    height: 10px;
    background: var(--bg-tertiary);
    border-radius: 10px;
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 10px;
    width: 0;
    transition: width 1s ease;
}

/* ===================================
   Contact Section
   =================================== */
.contact {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    position: relative;
}

.contact::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

.contact-content {
    max-width: 700px;
    margin: 0 auto;
}

.contact-form {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

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

.form-input,
.form-textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-family: var(--font-primary);
    font-size: 1rem;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-textarea {
    resize: vertical;
    min-height: 150px;
}

.form-error {
    display: block;
    color: #ef4444;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.form-message {
    margin-top: var(--spacing-sm);
    padding: var(--spacing-sm);
    border-radius: 10px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.form-message.success {
    background: #d1fae5;
    color: #065f46;
    display: block;
}

.form-message.error {
    background: #fee2e2;
    color: #991b1b;
    display: block;
}

.honeypot {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
}

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

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.footer-text {
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: var(--spacing-sm);
}

.footer-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 50%;
    color: var(--text-primary);
    transition: all var(--transition-base);
}

.footer-link:hover {
    background: var(--accent-gradient);
    color: white;
    transform: translateY(-3px);
}

/* ===================================
   Animations
   =================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    animation: fadeInUp 0.8s ease forwards;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--bg-primary);
        flex-direction: column;
        justify-content: flex-start;
        padding: var(--spacing-md);
        transition: left var(--transition-base);
        border-top: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
    
    .services-grid,
    .portfolio-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .about-highlights {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        justify-content: center;
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-lg: 2.5rem;
        --spacing-xl: 3rem;
    }
    
    .theme-toggle {
        width: 45px;
        height: 45px;
        top: 15px;
        right: 15px;
    }
    
    .contact-form {
        padding: var(--spacing-md);
    }
}