@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800;900&display=swap');

:root {
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #6366F1;
    --secondary: #10B981;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-600: #4B5563;
    --gray-900: #111827;
    --surface-light: #FFFFFF;
    --surface-dark: #0F172A;
    --transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--surface-light);
    color: var(--gray-900);
    margin: 0;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: var(--transition-base);
}

body.dark {
    background-color: var(--surface-dark);
    color: #F9FAFB;
}

/* Navigation Links */
.nav-link {
    position: relative;
    color: var(--gray-600);
    font-weight: 500;
    transition: color 0.3s ease;
    text-decoration: none;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s ease;
}

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

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

body.dark .nav-link {
    color: #D1D5DB;
}

/* Theme Button */
.theme-button {
    padding: 0.5rem;
    border-radius: 0.375rem;
    background: transparent;
    border: none;
    cursor: pointer;
    transition: var(--transition-base);
    color: var(--gray-600);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-button:hover {
    background: var(--gray-100);
}

body.dark .theme-button:hover {
    background: rgba(75, 85, 99, 0.2);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition-base);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 10px 25px rgba(79, 70, 229, 0.2);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 15px 35px rgba(79, 70, 229, 0.3);
}

.btn-secondary {
    border: 2px solid var(--gray-200);
    color: var(--gray-900);
    background: transparent;
}

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

body.dark .btn-secondary {
    border-color: rgba(209, 213, 219, 0.3);
    color: #F9FAFB;
}

body.dark .btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Social Links */
.social-link {
    color: var(--gray-600);
    transition: var(--transition-base);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.social-link:hover {
    color: var(--primary);
    transform: translateY(-3px);
}

body.dark .social-link {
    color: #D1D5DB;
}

/* Section Title */
.section-title {
    position: relative;
    padding-bottom: 1rem;
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 3rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
}
/* Card Styles */
.skill-card,
.project-card {
    border-radius: 0.5rem;
    overflow: hidden;
    background: var(--surface-light);
    transition: var(--transition-base);
}

body.dark .skill-card,
body.dark .project-card {
    background: #1E293B;
}

.skill-card {
    padding: 1.5rem;
}

.skill-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(79, 70, 229, 0.15);
}

.project-card {
    overflow: hidden;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

body.dark .project-card:hover {
    box-shadow: 0 20px 40px rgba(79, 70, 229, 0.1);
}

.project-overlay {
    transition: opacity 0.3s ease, transform 0.3s ease;
    opacity: 0;
    transform: translateY(20px);
}

.project-card:hover .project-overlay {
    opacity: 1;
    transform: translateY(0);
}

/* Timeline */
.timeline-item {
    position: relative;
    padding-left: 1.5rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 3px;
    height: calc(100% - 0.5rem);
    background: linear-gradient(180deg, var(--primary) 0%, rgba(79, 70, 229, 0.3) 100%);
    border-radius: 2px;
}

.timeline-item::after {
    content: '';
    position: absolute;
    left: -5px;
    top: 0.5rem;
    width: 13px;
    height: 13px;
    background: var(--primary);
    border-radius: 50%;
    border: 3px solid var(--surface-light);
    box-shadow: 0 0 0 3px var(--primary);
}

body.dark .timeline-item::after {
    border-color: var(--surface-dark);
}

/* Animations */
.animate-in {
    animation: fadeIn 0.5s ease-out forwards;
    opacity: 0;
}

.delay-100 {
    animation-delay: 100ms;
}

.delay-200 {
    animation-delay: 200ms;
}

.delay-300 {
    animation-delay: 300ms;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Utility Classes */
.delay-100 { animation-delay: 100ms; }
.delay-200 { animation-delay: 200ms; }
.delay-300 { animation-delay: 300ms; }

/* Accessibility */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .section-title {
        font-size: 1.875rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .nav-link {
        font-size: 0.95rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}