* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    padding: 20px;
}

.container {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

h1 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: #333;
}

#input {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

label {
    font-weight: 600;
    color: #555;
}

input[type="number"] {
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.3s;
}

input[type="number"]:focus {
    border-color: #4A90E2;
}

button {
    padding: 12px;
    background-color: #2c6cb5;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    font-weight: bold;
    transition: background 0.3s;
}

button:hover {
    background-color: #357ABD;
}

.result,
.score {
    margin-top: 20px;
    font-size: 1.1rem;
    font-weight: 600;
    min-height: 1.5em;
}

.score {
    color: #555;
    font-size: 1rem;
}

@media (max-width: 480px) {
    .container {
        padding: 1.5rem;
    }

    h1 {
        font-size: 1.2rem;
    }
}