/* ============================================
   CSS Variables
   ============================================ */
:root {
    /* Colors */
    --color-bg: #F3F4F6;
    --color-card: #FFFFFF;
    --color-text-primary: #1F2937;
    --color-text-secondary: #6B7280;
    --color-accent: #4F46E5;
    --color-accent-hover: #6366F1;
    --color-border: #E5E7EB;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --font-size-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
    --font-size-base: clamp(1rem, 0.9rem + 0.5vw, 1.125rem);
    --font-size-lg: clamp(1.125rem, 1rem + 0.65vw, 1.375rem);
    --font-size-xl: clamp(1.5rem, 1.2rem + 1.5vw, 2.25rem);
    --font-size-2xl: clamp(2rem, 1.5rem + 2.5vw, 3.5rem);
    
    /* Spacing */
    --spacing-xs: clamp(0.5rem, 0.4rem + 0.5vw, 0.75rem);
    --spacing-sm: clamp(0.75rem, 0.6rem + 0.75vw, 1rem);
    --spacing-md: clamp(1rem, 0.8rem + 1vw, 1.5rem);
    --spacing-lg: clamp(1.5rem, 1.2rem + 1.5vw, 2.5rem);
    --spacing-xl: clamp(2rem, 1.5rem + 2.5vw, 4rem);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 200ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 400ms ease;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
    list-style: none;
}

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

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

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

.section__title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.section__subtitle {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
}

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

.btn--primary:hover {
    background-color: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ============================================
   Header
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-base);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

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

.nav__menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav__link {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav__link:hover {
    color: var(--color-accent);
    background-color: var(--color-bg);
}

.nav__toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: var(--spacing-xs);
    background: none;
    border: none;
    cursor: pointer;
}

.nav__toggle-bar {
    width: 24px;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: all var(--transition-fast);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    padding-top: 8rem;
    padding-bottom: var(--spacing-xl);
    min-height: auto;
}

.hero__content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.hero__avatar {
    width: 120px;
    height: 120px;
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    background-color: var(--color-card);
}

.hero__avatar-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero__name {
    font-size: var(--font-size-2xl);
    font-weight: 800;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
    line-height: 1.2;
}

.hero__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
}

.hero__bio {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
    max-width: 500px;
    line-height: 1.7;
}

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

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

.hero__social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    background-color: var(--color-card);
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.hero__social-link:hover {
    color: var(--color-accent);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   Projects Section
   ============================================ */
.projects__filter {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
}

.projects__filter-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    background-color: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
}

.projects__filter-btn:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
}

.projects__filter-btn--active {
    color: white;
    background-color: var(--color-accent);
    border-color: var(--color-accent);
}

.projects__filter-btn--active:hover {
    color: white;
    background-color: var(--color-accent-hover);
}

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

.project-card {
    background-color: var(--color-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    opacity: 1;
    transform: scale(1);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.project-card--hidden {
    display: none;
}

.project-card--animating {
    animation: cardFadeIn 400ms ease forwards;
}

@keyframes cardFadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.project-card__image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background-color: var(--color-bg);
}

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

.project-card__badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-accent);
    background-color: rgba(79, 70, 229, 0.1);
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-xs);
}

.project-card__title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.project-card__description {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.project-card__link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-accent);
    transition: all var(--transition-fast);
}

.project-card__link:hover {
    color: var(--color-accent-hover);
    gap: 0.75rem;
}

/* ============================================
   Skills Section
   ============================================ */
.skills__list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
}

.skill-tag {
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-accent);
    background-color: rgba(79, 70, 229, 0.1);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
    cursor: default;
}

.skill-tag:hover {
    background-color: var(--color-accent);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   Experience Section
   ============================================ */
.experience__list,
.education__list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    max-width: 800px;
    margin: 0 auto;
}

.experience-card,
.education-card {
    background-color: var(--color-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--color-accent);
    transition: all var(--transition-base);
}

.experience-card:hover,
.education-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.experience-card__header,
.education-card__header {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
}

.experience-card__title,
.education-card__degree {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-text-primary);
}

.experience-card__company,
.education-card__school {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-accent);
}

.experience-card__period,
.education-card__period {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    background-color: var(--color-bg);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
}

.experience-card__description,
.education-card__description {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    line-height: 1.7;
}

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

.contact__content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact__text {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.contact__email {
    display: inline-block;
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
    transition: all var(--transition-fast);
}

.contact__email:hover {
    color: var(--color-accent-hover);
    text-decoration: underline;
}

.contact__location {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.contact__location i {
    margin-right: 0.5rem;
    color: var(--color-accent);
}

.contact__social {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.contact__social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full);
    background-color: var(--color-bg);
    color: var(--color-text-secondary);
    font-size: 1.25rem;
    transition: all var(--transition-base);
}

.contact__social-link:hover {
    background-color: var(--color-accent);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background-color: var(--color-text-primary);
    padding: var(--spacing-md) 0;
}

.footer__text {
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* ============================================
   Scroll Reveal Animation
   ============================================ */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 600ms ease;
}

.reveal--active {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .projects__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav__menu {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background-color: var(--color-card);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-xs);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav__menu--active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav__toggle {
        display: flex;
    }
    
    .nav__toggle--active .nav__toggle-bar:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .nav__toggle--active .nav__toggle-bar:nth-child(2) {
        opacity: 0;
    }
    
    .nav__toggle--active .nav__toggle-bar:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .hero {
        padding-top: 6rem;
    }
    
    .hero__avatar {
        width: 100px;
        height: 100px;
    }
    
    .projects__filter {
        flex-wrap: nowrap;
        overflow-x: auto;
        justify-content: flex-start;
        padding-bottom: var(--spacing-xs);
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
    }
    
    .projects__filter::-webkit-scrollbar {
        display: none;
    }
    
    .projects__grid {
        grid-template-columns: 1fr;
    }
    
    .experience-card__header,
    .education-card__header {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero__name {
        font-size: 1.75rem;
    }
    
    .section__title {
        font-size: 1.5rem;
    }
    
    .contact__email {
        font-size: var(--font-size-base);
    }
}