/* ============================================
   CSS Variables - Dark Theme Color Palette
   ============================================ */
:root {
    /* Primary Colors */
    --color-bg-primary: #0f172a;
    --color-bg-secondary: #1e293b;
    --color-bg-tertiary: #334155;
    
    /* Accent Colors */
    --color-accent-primary: #14b8a6;      /* Teal */
    --color-accent-hover: #0d9488;
    --color-accent-light: #2dd4bf;
    
    /* Text Colors */
    --color-text-primary: #f1f5f9;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    
    /* Border Colors */
    --color-border: #334155;
    --color-border-light: #475569;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 5rem;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
}

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

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

body {
    font-family: var(--font-family);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

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

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

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

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

/* ============================================
   Utility Classes
   ============================================ */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

.section__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-accent-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section__subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    text-align: center;
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn--primary {
    background-color: var(--color-accent-primary);
    color: var(--color-bg-primary);
}

.btn--primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(20, 184, 166, 0.4);
}

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

.btn--outline:hover {
    background-color: var(--color-accent-primary);
    color: var(--color-bg-primary);
    transform: translateY(-2px);
}

.btn--small {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.btn--full {
    width: 100%;
}

.btn svg {
    width: 18px;
    height: 18px;
}

/* ============================================
   Header / Navigation
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
}

.nav__logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-text-primary);
}

.nav__logo .logo-dot {
    color: var(--color-accent-primary);
}

.nav__menu {
    display: flex;
    gap: var(--spacing-lg);
}

.nav__link {
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--color-text-secondary);
    position: relative;
    padding: var(--spacing-xs) 0;
}

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

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

.nav__link:hover::after {
    width: 100%;
}

.nav__link.active {
    color: var(--color-accent-primary);
}

.nav__link.active::after {
    width: 100%;
}

/* Mobile Navigation Toggle */
.nav__toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-xs);
}

.hamburger {
    display: block;
    width: 25px;
    height: 2px;
    background-color: var(--color-text-primary);
    position: relative;
    transition: all var(--transition-base);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: all var(--transition-base);
}

.hamburger::before {
    top: -7px;
}

.hamburger::after {
    top: 7px;
}

/* Mobile menu active state */
.nav__toggle.active .hamburger {
    background-color: transparent;
}

.nav__toggle.active .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}

.nav__toggle.active .hamburger::after {
    top: 0;
    transform: rotate(-45deg);
}

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

.hero__container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.hero__greeting {
    font-size: var(--font-size-lg);
    color: var(--color-accent-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.hero__title {
    font-size: var(--font-size-5xl);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--spacing-sm);
}

.hero__subtitle {
    font-size: var(--font-size-2xl);
    font-weight: 400;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.hero__description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 500px;
    margin-bottom: var(--spacing-lg);
}

.hero__buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

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

.hero__image-wrapper {
    position: relative;
    width: 350px;
    height: 350px;
}

.hero__placeholder {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-bg-secondary) 0%, var(--color-bg-tertiary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-5xl);
    font-weight: 700;
    color: var(--color-accent-primary);
    border: 3px solid var(--color-accent-primary);
    box-shadow: 0 0 60px rgba(20, 184, 166, 0.3);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid var(--color-accent-primary);
    border-bottom: 2px solid var(--color-accent-primary);
    transform: rotate(45deg);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(10px);
    }
    60% {
        transform: translateX(-50%) translateY(5px);
    }
}

/* ============================================
   About Section
   ============================================ */
.about__container {
    max-width: 1000px;
}

.about__content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.about__image {
    display: flex;
    justify-content: center;
}

.about__image-wrapper {
    position: relative;
    width: 280px;
    height: 280px;
}

.about__placeholder {
    width: 100%;
    height: 100%;
    border-radius: var(--radius-xl);
    background: linear-gradient(135deg, var(--color-bg-secondary) 0%, var(--color-bg-tertiary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--color-accent-primary);
    border: 2px solid var(--color-accent-primary);
}

.about__text p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about__stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.stat {
    text-align: center;
}

.stat__number {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-accent-primary);
}

.stat__label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
}

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

.skills__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

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

.skill-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-primary);
    box-shadow: 0 10px 30px rgba(20, 184, 166, 0.15);
}

.skill-card__icon {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--spacing-md);
    color: var(--color-accent-primary);
}

.skill-card__icon svg {
    width: 100%;
    height: 100%;
}

.skill-card__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.skill-card__desc {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.5;
}

/* ============================================
   Portfolio Section
   ============================================ */
.portfolio__grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-base);
}

.project-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-primary);
    box-shadow: 0 10px 30px rgba(20, 184, 166, 0.15);
}

.project-card__image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.project-card__placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-primary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-accent-primary);
}

.project-card__content {
    padding: var(--spacing-lg);
}

.project-card__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.project-card__description {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

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

.tag {
    font-size: var(--font-size-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--color-bg-tertiary);
    color: var(--color-accent-light);
    border-radius: var(--radius-full);
}

.project-card__links {
    display: flex;
    gap: var(--spacing-sm);
}

/* ============================================
   Contact Section
   ============================================ */
.contact__content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
}

.contact__info h3 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.contact__info p {
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

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

.social-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    transition: all var(--transition-base);
}

.social-link:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-accent-primary);
}

.social-link svg {
    width: 24px;
    height: 24px;
}

.social-link span {
    font-size: var(--font-size-base);
    font-weight: 500;
}

/* Contact Form */
.contact__form {
    background-color: var(--color-bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}

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

.form-label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.form-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-base);
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.form-input::placeholder {
    color: var(--color-text-muted);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-accent-primary);
    box-shadow: 0 0 0 3px rgba(20, 184, 166, 0.1);
}

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

/* Form Success Message */
.form-success {
    display: none;
    text-align: center;
    padding: var(--spacing-lg);
    background-color: rgba(20, 184, 166, 0.1);
    border: 1px solid var(--color-accent-primary);
    border-radius: var(--radius-md);
    color: var(--color-accent-primary);
}

.form-success.active {
    display: block;
}

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

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

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

.footer__credit {
    font-style: italic;
}

/* ============================================
   Responsive Design - Tablet (768px)
   ============================================ */
@media (max-width: 992px) {
    :root {
        --font-size-5xl: 2.75rem;
        --font-size-4xl: 2rem;
    }
    
    .hero__container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero__description {
        max-width: none;
    }
    
    .hero__buttons {
        justify-content: center;
    }
    
    .hero__image {
        order: -1;
    }
    
    .hero__image-wrapper {
        width: 280px;
        height: 280px;
    }
    
    .about__content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .about__image {
        justify-content: center;
    }
    
    .about__stats {
        justify-items: center;
    }
    
    .skills__grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .portfolio__grid {
        grid-template-columns: 1fr;
    }
    
    .contact__content {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Responsive Design - Mobile (480px)
   ============================================ */
@media (max-width: 768px) {
    :root {
        --font-size-5xl: 2.25rem;
        --font-size-4xl: 1.75rem;
        --font-size-3xl: 1.5rem;
        --font-size-2xl: 1.25rem;
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    /* Navigation - Mobile */
    .nav__toggle {
        display: flex;
    }
    
    .nav__menu {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        flex-direction: column;
        background-color: var(--color-bg-secondary);
        padding: var(--spacing-lg);
        gap: 0;
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-150%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav__menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav__item {
        width: 100%;
    }
    
    .nav__link {
        display: block;
        padding: var(--spacing-md);
        border-radius: var(--radius-md);
    }
    
    .nav__link::after {
        display: none;
    }
    
    .nav__link:hover {
        background-color: var(--color-bg-tertiary);
    }
    
    /* Hero */
    .hero {
        padding-top: 100px;
        min-height: auto;
        padding-bottom: var(--spacing-2xl);
    }
    
    .hero__image-wrapper {
        width: 220px;
        height: 220px;
    }
    
    .hero__buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
    }
    
    .scroll-indicator {
        display: none;
    }
    
    /* About */
    .about__image-wrapper {
        width: 200px;
        height: 200px;
    }
    
    .about__stats {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    /* Skills */
    .skills__grid {
        grid-template-columns: 1fr;
    }
    
    /* Portfolio */
    .portfolio__grid {
        grid-template-columns: 1fr;
    }
    
    /* Contact */
    .contact__social {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .social-link {
        flex: 1;
        min-width: 120px;
        justify-content: center;
    }
    
    /* Footer */
    .footer__container {
        flex-direction: column;
        text-align: center;
    }
}

/* ============================================
   Small Mobile (375px)
   ============================================ */
@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero__image-wrapper {
        width: 180px;
        height: 180px;
    }
    
    .about__image-wrapper {
        width: 160px;
        height: 160px;
    }
    
    .project-card__links {
        flex-direction: column;
    }
    
    .contact__social {
        justify-content: center;
    }
}

/* ============================================
   Animations & Transitions
   ============================================ */
@media (prefers-reduced-motion: no-preference) {
    .skill-card,
    .project-card {
        animation: fadeInUp 0.6s ease-out backwards;
    }
    
    .skill-card:nth-child(1) { animation-delay: 0.1s; }
    .skill-card:nth-child(2) { animation-delay: 0.2s; }
    .skill-card:nth-child(3) { animation-delay: 0.3s; }
    .skill-card:nth-child(4) { animation-delay: 0.4s; }
    .skill-card:nth-child(5) { animation-delay: 0.5s; }
    .skill-card:nth-child(6) { animation-delay: 0.6s; }
    
    .project-card:nth-child(1) { animation-delay: 0.1s; }
    .project-card:nth-child(2) { animation-delay: 0.2s; }
    .project-card:nth-child(3) { animation-delay: 0.3s; }
    .project-card:nth-child(4) { animation-delay: 0.4s; }
}

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

/* ============================================
   Print Styles
   ============================================ */
@media print {
    .header,
    .scroll-indicator,
    .btn,
    .project-card__links,
    .contact__form,
    .contact__social {
        display: none !important;
    }
    
    body {
        background-color: white;
        color: black;
    }
    
    .section {
        page-break-inside: avoid;
    }
}