body {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    margin: 0;
    background: #f4f6f8;
    color: #1f2933;
}

header {
    background: #0b3d91;
    color: #fff;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    margin: 0;
    font-size: 1.4rem;
}

header .user-info {
    font-size: 0.95rem;
}

header a {
    color: #fff;
    text-decoration: none;
    margin-left: 16px;
    font-weight: 600;
}

main {
    max-width: 960px;
    margin: 30px auto;
    padding: 0 16px 40px;
}

.card {
    background: #fff;
    border-radius: 10px;
    padding: 24px;
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.1);
    margin-bottom: 20px;
}

.card h2 {
    margin-top: 0;
    font-size: 1.25rem;
}

form label {
    display: block;
    margin-top: 16px;
    font-weight: 600;
}

form input,
form select {
    width: 100%;
    padding: 10px;
    margin-top: 6px;
    border: 1px solid #cbd2d9;
    border-radius: 6px;
    font-size: 1rem;
    box-sizing: border-box;
}

form button {
    margin-top: 18px;
    background: #0b3d91;
    color: #fff;
    border: none;
    padding: 12px 20px;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
}

form button:hover {
    background: #0a3277;
}

.flash {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-weight: 600;
}

.flash.success {
    background: #d3f9d8;
    color: #1b5e20;
}

.flash.error {
    background: #fdecea;
    color: #c62828;
}

.flash.info {
    background: #e3f2fd;
    color: #0d47a1;
}

.login-card {
    text-align: center;
}

.login-card button {
    background: #0b3d91;
    color: #fff;
    border: none;
    padding: 12px 20px;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
}

.login-card button:disabled {
    background: #9aa5b1;
    cursor: not-allowed;
}

.layout-columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    grid-gap: 20px;
}

.logout-link {
    margin-left: 12px;
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 12px;
    border-radius: 16px;
}

.card-description {
    margin-top: 8px;
    color: #52606d;
    font-size: 0.9rem;
}

.table-container {
    margin-top: 16px;
    overflow-x: auto;
}

.certificate-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.certificate-table thead {
    background: #f1f5f9;
}

.certificate-table th,
.certificate-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
    vertical-align: top;
}

.certificate-table tbody tr:hover {
    background: #f8fafc;
}

.certificate-table th.actions,
.certificate-table td.actions {
    text-align: right;
    white-space: nowrap;
}

.certificate-table td.actions form {
    display: inline;
}

.danger-button {
    background: #c62828;
    color: #fff;
    border: none;
    padding: 8px 14px;
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
}

.danger-button:hover {
    background: #a62323;
}

.mono {
    font-family: 'SFMono-Regular', Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
    font-size: 0.9rem;
    word-break: break-all;
}