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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
}

header {
    background-color: #f1f1f1;
    padding: 1.5rem;
    text-align: center;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

header p {
    font-size: 1.2rem;
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.logo {
    width: 300px;
    display: block;
    margin-bottom: 1rem;
}

form {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.birthdate-label {
    font-size: 1.2rem;
}

.input-group {
    display: flex;
    gap: 1rem;
}

form input {
    font-size: 1rem;
}

form button {
    font-size: 1.2rem;
    background-color: #333;
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
}

form button:hover {
    opacity: 0.9;
}

form button:disabled {
    cursor: progress;
    background-color: lightgray;
}

.kakao-ad {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 20px;
    min-width: 350px;
    min-height: 200px;
}