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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.25rem;
    font-size: 16px;
}

.container {
    width: 100%;
    max-width: 42.5rem;
    margin: 0 auto;
}

.card {
    background: white;
    border-radius: 1.5rem;
    padding: 3rem 2rem;
    box-shadow: 0 1.25rem 3.75rem rgba(0, 0, 0, 0.3);
}

.profile {
    text-align: center;
    margin-bottom: 2.5rem;
}

.profile h1 {
    font-size: 2rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.profile .subtitle {
    font-size: 1.125rem;
    color: #6b7280;
    font-weight: 400;
}

.links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.link-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: white;
    border: 0.125rem solid #e5e7eb;
    border-radius: 0.75rem;
    text-decoration: none;
    color: #1f2937;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.2s ease;
    cursor: pointer;
}

.link-button:hover {
    background: #f9fafb;
    border-color: #667eea;
    transform: translateY(-0.125rem);
    box-shadow: 0 0.25rem 0.75rem rgba(102, 126, 234, 0.2);
}

.link-button:active {
    transform: translateY(0);
}

.link-button .icon {
    width: 1.5rem;
    height: 1.5rem;
    flex-shrink: 0;
}

.link-button span {
    flex: 1;
    text-align: center;
}

/* Hapsen Tech Section */
.hapsen-section {
    margin-bottom: 2.5rem;
    padding-bottom: 2.5rem;
    border-bottom: 0.125rem solid #e5e7eb;
}

/* CodeSeoul Section */
.codeseoul-section {
    margin-top: 2.5rem;
    padding-top: 2.5rem;
    margin-bottom: 2.5rem;
    padding-bottom: 2.5rem;
    border-top: 0.125rem solid #e5e7eb;
    border-bottom: 0.125rem solid #e5e7eb;
}

/* Personal Section */
.personal-section {
    margin-top: 2.5rem;
    padding-top: 2.5rem;
    border-top: 0.125rem solid #e5e7eb;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    text-align: center;
    margin-bottom: 0.5rem;
}

.section-description {
    font-size: 0.9375rem;
    color: #6b7280;
    text-align: center;
    margin-bottom: 1.5rem;
}

/* Responsive design */
@media (max-width: 40rem) {
    .card {
        padding: 2rem 1.5rem;
    }

    .profile h1 {
        font-size: 1.75rem;
    }

    .profile .subtitle {
        font-size: 1rem;
    }

    .link-button {
        padding: 0.875rem 1.25rem;
        font-size: 0.9375rem;
    }
}

@media (max-width: 25rem) {
    .link-button span {
        font-size: 0.875rem;
    }
}