html,
body {
    width: 100%;
    height: 100%;
    margin: 0;
}

body {
    overflow: hidden;
    background: #111;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    color: #e0e0e0;
}

/* Landing overlay */
main {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: #111;
    z-index: 10;
    transition: opacity 300ms ease;
}

main.hidden {
    opacity: 0;
    pointer-events: none;
}

.timestamp-grid {
    position: fixed;
    left: 50%;
    top: 50%;
    display: none;
    grid-template-columns: repeat(8, 1fr);
    grid-template-rows: repeat(7, 1fr);
    width: 80vmin;
    aspect-ratio: 8 / 7;
    transform: translate(-50%, -50%);
    z-index: 1;
}

body.calibrating .timestamp-grid {
    display: grid;
}

.timestamp-cell {
    min-width: 0;
    min-height: 0;
}

.card {
    max-width: 560px;
    text-align: center;
}

h1 {
    margin: 0 0 16px;
    font-size: 28px;
    font-weight: 700;
    color: #fff;
}

p {
    margin: 6px 0;
    font-size: 15px;
    line-height: 1.5;
}

.steps {
    margin: 20px 0;
    text-align: left;
}

.steps p {
    margin: 8px 0;
}

.warning {
    margin: 20px auto;
    padding: 12px 16px;
    max-width: 480px;
    border: 1px solid #a04000;
    border-radius: 6px;
    background: rgba(255, 109, 0, 0.1);
    color: #ffab40;
    font-size: 13px;
    line-height: 1.5;
}

button {
    margin: 24px 0 12px;
    padding: 12px 48px;
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    background: #2979FF;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background 150ms ease;
}

button:hover {
    background: #448AFF;
}

button:disabled {
    background: #555;
    cursor: default;
}

.status-text {
    font-size: 13px;
    color: #999;
    min-height: 1.5em;
}