body {
    font-family: Arial, sans-serif;
    background: #f4f6f9;
    margin: 0;
    padding: 20px;
}

/* Calculator Box */

.container {
    max-width: 550px;
    margin: auto;
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h1 {
    text-align: center;
}

.subtext {
    text-align: center;
    color: #666;
    margin-bottom: 20px;
}

input {
    width: 100%;
    padding: 12px;
    margin-bottom: 12px;
    border: 1px solid #ddd;
    border-radius: 8px;
    box-sizing: border-box;
}

button {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    background: #2563eb;
    color: white;
    font-size: 16px;
    cursor: pointer;
}

button:hover {
    background: #1d4ed8;
}

.result {
    margin-top: 20px;
    padding: 15px;
    background: #f8fafc;
    border-radius: 8px;
    text-align: center;
}

.result p {
    margin: 10px 0;
    font-size: 18px;
    font-weight: bold;
}

/* Content Sections */

section {
    max-width: 800px;
    margin: 40px auto;
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    line-height: 1.8;
}

section h2 {
    color: #2563eb;
    margin-bottom: 15px;
}

section p {
    margin-bottom: 15px;
}

section ul {
    padding-left: 25px;
}

section li {
    margin-bottom: 10px;
}

/* Links */

a {
    color: #2563eb;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Footer */

footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: #666;
}

/* Mobile */

@media (max-width: 768px) {

    body {
        padding: 15px;
    }

    .container,
    section {
        width: 100%;
        box-sizing: border-box;
    }

    h1 {
        font-size: 28px;
    }
}