/* Support note at bottom */
.support-note {
    margin-top: 36px;
    font-size: 1em;
    color: #334155;
    text-align: center;
}
.support-note a {
    color: #2563eb;
    text-decoration: underline;
    font-weight: 500;
}
/* Error highlight text */
.error-highlight {
    color: #ef4444;
    font-weight: bold;
}
/* Submit button spacing */
.test-btn.spaced {
    margin-top: 20px;
}
body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: linear-gradient(120deg, #e0e7ff 0%, #c7d2fe 100%);
    margin: 0;
    padding: 0;
    min-height: 100vh;
}
.container {
    max-width: 500px;
    margin: 60px auto;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(60, 90, 180, 0.12);
    padding: 32px 24px 40px 24px;
    text-align: center;
}
h1 {
    color: #2563eb;
    margin-bottom: 16px;
}
.ip {
    font-size: 1.2em;
    color: #374151;
    margin-bottom: 18px;
}
.instructions {
    color: #334155;
    margin-bottom: 28px;
}
.test-btn {
    background: #2563eb;
    color: #fff;
    font-size: 1.3em;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    padding: 18px 0;
    width: 100%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
    transition: background 0.2s;
}
.test-btn:hover {
    background: #1d4ed8;
}
.note {
    font-size: 0.95em;
    color: #64748b;
    margin-top: 24px;
}
.note .highlight {
    color: #f59e42;
    font-weight: bold;
}
/* Styles for mtu.php */
.result {
    font-size: 1.2em;
    color: #2563eb;
    margin: 24px 0 18px 0;
    font-weight: 600;
}
.failed {
    color: #ef4444;
    font-weight: bold;
    font-size: 1.1em;
    margin: 24px 0 18px 0;
}
.router-mtu {
    font-size: 1.1em;
    color: #059669;
    font-weight: bold;
    margin-bottom: 36px;
}
.back-btn {
    background: #2563eb;
    color: #fff;
    font-size: 1em;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    padding: 12px 0;
    width: 100%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
    transition: background 0.2s;
    margin-top: 24px;
}
.back-btn:hover {
    background: #1d4ed8;
}

.loader {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    vertical-align: middle;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
#loadingIndicator {
    display: none;
    margin-top: 15px;
}