.container {
    max-width: 900px;
    margin: auto;
}
.card {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 25px;
}
h1, h2 {
    margin-top: 0;
}
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 15px;
}
label {
    font-weight: bold;
    display: block;
    margin-bottom: 5px;
}
input {
    width: 100%;
    padding: 10px;
    box-sizing: border-box;
}
button {
    padding: 12px 18px;
    background: #2563eb;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}
.success {
    color: green;
    font-weight: bold;
}
.error {
    color: darkred;
    font-weight: bold;
}
code, pre {
    background: #eef2f7;
    padding: 10px;
    display: block;
    border-radius: 6px;
    overflow-x: auto;
}