* {
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
    background: #f3f6fb;
    margin: 0;
    padding: 30px;
    color: #222;
}

.container {
    max-width: 1000px;
    margin: auto;
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

h1 {
    text-align: center;
    color: #173b70;
    margin-bottom: 30px;
}

h2 {
    color: #173b70;
    margin-top: 25px;
}

form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

    form label {
        font-weight: bold;
        align-self: end;
    }

    form input {
        width: 100%;
        padding: 11px;
        border: 1px solid #cbd3df;
        border-radius: 6px;
        font-size: 15px;
    }

button {
    background: #2459a6;
    color: white;
    border: none;
    padding: 11px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

    button:hover {
        background: #173b70;
    }

#studentForm button {
    grid-column: 1 / -1;
}

#message {
    margin-top: 15px;
    font-weight: bold;
    color: #187344;
}

.table-wrapper {
    overflow-x: auto;
    margin-top: 15px;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

th, td {
    border: 1px solid #d8deea;
    padding: 12px;
    text-align: left;
}

th {
    background: #173b70;
    color: white;
}

tr:nth-child(even) {
    background: #f3f6fb;
}

@media (max-width: 600px) {
    body {
        padding: 12px;
    }

    .container {
        padding: 18px;
    }

    form {
        grid-template-columns: 1fr;
    }
}