/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    font-weight: 400;
    line-height: 1.6;
    color: #111111;
    background-color: #ffffff;
}

/* Layout */
.container {
    width: 100%;
    max-width: 720px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem 0;
    font-size: 1rem;
    font-weight: 600;
    position: sticky;
    top: 0;
    background-color: #ffffff;
    z-index: 100;
    transition: all 0.3s ease;
}

.nav-left .nav-link {
    font-weight: 700;
}

.nav-right {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s ease;
}

.nav-link:hover {
    color: #005fcc;
}

/* Typography */
h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #000000;
}

h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #000000;
}

h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

p {
    margin-bottom: 1rem;
    color: #111111;
}

/* Links */
.link {
    color: inherit;
    text-decoration: underline;
    transition: color 0.2s ease, text-decoration 0.2s ease;
}

.link:hover {
    color: #005fcc;
    text-decoration: none;
}

/* Sections */
.section {
    margin-bottom: 3rem;
    opacity: 0;
    transform: translateY(20px);
    animation: slideUp 0.5s ease-out forwards;
    scroll-margin-top: 100px;
}

.section-title {
    margin-bottom: 1.5rem;
}

/* Hero section */
.hero {
    padding: 4rem 0;
    animation-delay: 0.1s;
    margin-bottom: 0;
}

.hero-title {
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.125rem;
    color: #555555;
    margin-bottom: 2rem;
}

.hero-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

/* About section */
.about {
    animation-delay: 1.3s;
}

/* Projects section */
.projects {
    animation-delay: 0.3s;
}

/* Project styles */
.project-item {
    opacity: 0;
    transform: translateY(20px);
    animation: slideUp 0.5s ease-out forwards;
}

.projects .project-item:nth-child(1) { animation-delay: 0.4s; }
.projects .project-item:nth-child(2) { animation-delay: 0.5s; }
.projects .project-item:nth-child(3) { animation-delay: 0.6s; }
.projects .project-item:nth-child(4) { animation-delay: 0.7s; }
.projects .project-item:nth-child(5) { animation-delay: 0.8s; }

.project-title {
    margin-bottom: 0.5rem;
}

.project-description {
    color: #555555;
    margin-bottom: 0;
}

/* Project styles continued */
.project-item:not(:last-child) {
    margin-bottom: 2.5rem;
}

/* Contact section */
.contact {
    animation-delay: 0.8s;
}

/* Footer */
.footer {
    padding: 2rem 0;
    text-align: center;
    font-size: 0.875rem;
    color: #555555;
    border-top: 1px solid #f0f0f0;
    margin-top: 2rem;
    opacity: 0;
    animation: fadeIn 0.6s ease-out forwards;
    animation-delay: 1.0s;
}

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

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


/* Mobile menu */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 24px;
    height: 24px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    gap: 3px;
}

.hamburger-line {
    width: 20px;
    height: 2px;
    background-color: #111111;
    transition: all 0.3s ease;
    transform-origin: center;
}

.mobile-menu-btn.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }
    
    .header {
        padding: 1rem 0;
        flex-wrap: wrap;
        gap: 0.75rem;
    }
    
    .nav-right {
        gap: 0.75rem;
        font-size: 0.9rem;
    }
    
    .section {
        scroll-margin-top: 80px;
    }
}

@media (max-width: 640px) {
    .container {
        padding: 1rem 0.75rem;
    }
    
    .header {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        gap: 1rem;
        padding: 0.75rem 0;
        position: relative;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .nav-right {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: #ffffff;
        flex-direction: column;
        gap: 1rem;
        padding: 1rem 0;
        border-top: 1px solid #f0f0f0;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }
    
    .nav-right.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    h1 {
        font-size: 1.75rem;
        line-height: 1.2;
    }
    
    h2 {
        font-size: 1.25rem;
    }
    
    .hero {
        padding: 1.5rem 0;
        margin-bottom: 0;
    }
    
    .hero-description {
        font-size: 1rem;
        margin-bottom: 1.5rem;
    }
    
    .hero-links {
        gap: 1rem;
        flex-direction: row;
        align-items: flex-start;
    }
    
    .section {
        margin-bottom: 2.5rem;
        scroll-margin-top: 120px;
    }
    
    .section-title {
        margin-bottom: 1rem;
    }
    
    
    .timeline-date {
        font-size: 0.8rem;
        margin-bottom: 0.125rem;
    }
    
    .project-description,
    .article-description {
        font-size: 0.9rem;
        line-height: 1.5;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0.75rem 0.5rem;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    h2 {
        font-size: 1.125rem;
    }
    
    .header {
        padding: 0.5rem 0;
    }
    
    .nav-right {
        font-size: 0.85rem;
        gap: 1rem;
    }
    
    .hero {
        padding: 1rem 0;
    }
    
    .hero-description {
        font-size: 0.95rem;
    }
    
    .section {
        margin-bottom: 2rem;
        scroll-margin-top: 100px;
    }
    
    
    .project-description,
    .article-description {
        font-size: 0.85rem;
    }
    
    .timeline-date {
        font-size: 0.75rem;
    }
}