* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    background: #f4f5f7;
    color: #1f2933;
}

.container {
    max-width: 420px;
    margin: 48px auto;
    padding: 24px;
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

h1 {
    margin-top: 0;
    font-size: 1.6rem;
    text-align: center;
}

h2 {
    font-size: 1.2rem;
}

form {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-weight: 600;
    margin-top: 8px;
}

input {
    padding: 10px;
    font-size: 1rem;
    border: 1px solid #cbd2d9;
    border-radius: 4px;
}

button {
    margin-top: 12px;
    padding: 10px 16px;
    font-size: 1rem;
    border: none;
    border-radius: 4px;
    background: #2563eb;
    color: #ffffff;
    cursor: pointer;
}

button:hover:not(:disabled) {
    background: #1d4ed8;
}

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

button.secondary {
    background: #e4e7eb;
    color: #1f2933;
}

button.secondary:hover:not(:disabled) {
    background: #cbd2d9;
}

button.checkin {
    display: block;
    width: 100%;
    padding: 20px;
    font-size: 1.4rem;
    font-weight: 700;
    background: #16a34a;
}

button.checkin:hover:not(:disabled) {
    background: #15803d;
}

.status {
    min-height: 1.2em;
    color: #166534;
}

.error {
    min-height: 1.2em;
    color: #b91c1c;
    font-weight: 600;
    white-space: pre-wrap;
    word-break: break-word;
}

.last-checkin {
    margin-top: 24px;
}

.hidden {
    display: none !important;
}