* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: #f8fafc;
    color: #1e293b;
    line-height: 1.6;
    padding: 0 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px 0;
}

.site-header {
    padding: 20px 0;
    border-bottom: 1px solid #e2e8f0;
    margin-bottom: 40px;
}

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

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: #0f172a;
}

section {
    margin-bottom: 60px;
}

h1 {
    font-size: 2.8rem;
    font-weight: 700;
    letter-spacing: -1px;
    line-height: 1.2;
    margin-bottom: 20px;
}

h2 {
    font-size: 1.8rem;
    font-weight: 600;
    letter-spacing: -0.5px;
    margin-bottom: 24px;
    border-bottom: 2px solid #e2e8f0;
    padding-bottom: 8px;
}

h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.subtitle {
    font-size: 1.2rem;
    color: #475569;
    max-width: 600px;
    margin-bottom: 30px;
}

p {
    color: #334155;
    margin-bottom: 16px;
}

.btn {
    display: inline-block;
    background-color: #0f172a;
    color: white;
    font-weight: 600;
    padding: 12px 28px;
    border-radius: 8px;
    text-decoration: none;
    transition: background-color 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    background-color: #1e293b;
}

.btn-outline {
    background-color: transparent;
    color: #0f172a;
    border: 1px solid #cbd5e1;
}

.btn-outline:hover {
    background-color: #f1f5f9;
}

.btn-group {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}

.project-card {
    background: white;
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    border: 1px solid #e2e8f0;
}

.project-card .tagline {
    font-weight: 500;
    color: #1e293b;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.project-card p {
    font-size: 0.95rem;
    color: #475569;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 16px 0 20px;
}

.tag {
    background-color: #f1f5f9;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
    color: #475569;
}

.project-links a {
    color: #0f172a;
    text-decoration: none;
    font-weight: 500;
    margin-right: 20px;
    font-size: 0.95rem;
}

.project-links a:hover {
    text-decoration: underline;
}

.contact-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 500px;
}

.contact-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    background: white;
    border-radius: 10px;
    border: 1px solid #e2e8f0;
    text-decoration: none;
    color: #0f172a;
    transition: border-color 0.2s, transform 0.1s;
}

.contact-item:hover {
    border-color: #94a3b8;
    transform: translateY(-1px);
}

.contact-item .label {
    font-weight: 500;
}

.contact-item .value {
    color: #64748b;
}

.contact-item .arrow {
    color: #94a3b8;
}

.contact-item.note {
    cursor: default;
}

.contact-item.note:hover {
    transform: none;
    border-color: #e2e8f0;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.about-stats {
    display: flex;
    flex-direction: column;
}

.about-stats div {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid #e2e8f0;
}

.about-stats .label {
    color: #64748b;
}

.challenge-box {
    margin-top: 40px;
    padding: 30px;
    background: white;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
}

.challenge-box h2 {
    border-bottom: none;
    padding-bottom: 0;
}

.challenge-box p {
    margin-bottom: 20px;
}

@media (max-width: 640px) {
    .nav {
        flex-direction: column;
        gap: 12px;
    }

    h1 {
        font-size: 2.2rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .about-grid {
        grid-template-columns: 1fr;
    }
}