:root {
    --primary: #1e40af;
    --bg: #f5f6fa;
}

body {
    font-family: Arial, sans-serif;
    background-color: var(--bg);
    margin: 0;
    padding: 0;
    line-height: 1.5;
    color: #333;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding-bottom: 2rem;
}

h1 {
    text-align: center;
    background: var(--primary);
    color: #fff;
    margin: 0;
    padding: 1rem 0;
}

section {
    background: #fff;
    margin: 1rem auto;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    width: 90%;
    max-width: 800px;
}

section h2 {
    margin-top: 0;
    color: var(--primary);
    font-size: 1.25rem;
}

form {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
}

form input[type="text"],
form input[type="number"],
form textarea {
    flex: 1 1 200px;
    padding: 0.4em;
    border: 1px solid #ccc;
    border-radius: 4px;
}

form button,
button#scaleBtn {
    padding: 0.4em 0.8em;
    border: none;
    background: var(--primary);
    color: #fff;
    border-radius: 4px;
    cursor: pointer;
}

form button:hover,
button#scaleBtn:hover {
    background-color: #1d4ed8;
}

pre, p#trainOut {
    background: #f0f0f0;
    padding: 0.5rem;
    border-radius: 4px;
    overflow-x: auto;
}

label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

img#plot {
    max-width: 100%;
    height: auto;
    display: block;
    margin: auto;
}