:root {
    --bg1: #f4f7fb;
    --bg2: #eef6ff;
    --card: #ffffff;
    --text: #2c3e50;
    --muted: #6b7c8f;
    --accent: #4a90d9;
    --accent-soft: rgba(74, 144, 217, 0.12);
    --shadow: 0 12px 40px rgba(41, 72, 112, 0.12);
    --radius: 20px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
    height: 100%;
    touch-action: manipulation;
    -webkit-text-size-adjust: 100%;
}
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: linear-gradient(165deg, var(--bg1) 0%, var(--bg2) 55%, #e8f0fc 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px 20px env(safe-area-inset-bottom, 24px);
}
.panel {
    width: 100%;
    max-width: 360px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 36px 28px 32px;
    text-align: center;
}
.mark {
    width: 72px;
    height: 72px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: var(--accent-soft);
    display: flex;
    align-items: center;
    justify-content: center;
}
.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid rgba(74, 144, 217, 0.2);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.85s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}
.panel h1 {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    margin-bottom: 10px;
}
p.lead {
    font-size: 0.95rem;
    color: var(--muted);
    line-height: 1.65;
    margin-bottom: 8px;
}
p.hint {
    font-size: 0.8rem;
    color: #95a5b8;
    margin-top: 18px;
}
.error {
    display: none;
    margin-top: 20px;
    padding: 14px;
    background: #fff5f5;
    border-radius: 12px;
    color: #c0392b;
    font-size: 0.88rem;
    line-height: 1.5;
}
.error.visible { display: block; }
button.retry {
    display: none;
    margin-top: 16px;
    width: 100%;
    padding: 12px 16px;
    border: none;
    border-radius: 12px;
    background: var(--accent);
    color: #fff;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
}
button.retry.visible { display: inline-block; }