body {
    font-family: var(--font-main, 'Segoe UI'), sans-serif;
    background: linear-gradient(to bottom, #d0f0ff, #a8e0ff);
    margin: 0;
}

.calculator {
    background-color: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 450px;
    text-align: center;
    margin: 40px auto; /* center and add some vertical spacing */
}

h1 {
    color: #0077b6;
}

input, select {
    width: 80%;
    padding: 10px;
    margin: 10px 0;
    border-radius: 8px;
    border: 1px solid #ccc;
}

button {
    background-color: #0077b6;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #005f8d;
}

#result {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
    color: #023e8a;
}

label {
    display: block;
    margin-top: 10px;
    font-weight: bold;
    color: #555;
}

:root {
    --primary-color: #004e64;
    --accent-color: #00a6a6;
    --font-main: 'Segoe UI', sans-serif;
}

/* Reset margins and paddings on everything */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Reset html and body */
html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: var(--font-main);
}

header {
    width: 100vw; /* full viewport width */
    position: relative;
    left: 0;
    right: 0;
    margin: 0;
    padding: 20px 40px;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.container {
    width: 100%; /* full width container */
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 28px;
    margin: 0;
}

nav a {
    color: white;
    margin-left: 20px;
    text-decoration: none;
    font-weight: 500;
}

nav a:hover {
    text-decoration: underline;
}