.astra-auth { background: var(--mint); }
.astra-auth .reading-progress { display: none; }
.signin-scene {
    position: relative;
    isolation: isolate;
    min-height: calc(100svh - var(--nav-height));
    padding: 32px 20px max(28px, env(safe-area-inset-bottom));
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 16px;
    overflow: hidden;
    background: var(--mint);
}
.signin-art { position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; object-fit: cover; object-position: center; }
.signin-scene::before { content: ''; position: absolute; inset: 0; z-index: -1; background: linear-gradient(90deg, #eaf8f210, #eaf8f260 35% 65%, #eaf8f210); }
.signin-panel {
    width: min(100%, 520px);
    padding: 28px 36px 24px;
    border: 1px solid #abcbbb;
    border-radius: 8px;
    background: white;
    box-shadow: 0 5px 0 #dcebe2, 0 6px 0 #abcbbb, 0 24px 64px #203d3624;
    position: relative;
}
.signin-panel::before { content: ''; position: absolute; top: -1px; left: 8px; right: 8px; height: 4px; background: linear-gradient(90deg, #f29b90 0 33.333%, #ffdc76 33.333% 66.666%, #a8d5c1 66.666%); }
.signin-book { display: grid; place-items: center; width: 56px; height: 56px; margin: 0 auto 16px; border: 1px solid #e1bc57; border-radius: 50%; background: #fff3ce; box-shadow: 0 3px 0 #efdb9e, inset 0 0 0 5px #fffbef; }
.signin-book img { width: 28px; height: 28px; transform: rotate(-8deg); }
#astra-auth-frame { width: 100%; height: 500px; display: block; border: 0; background: #fff; color-scheme: light; transition: height .32s cubic-bezier(.2,.7,.2,1); }
.signin-fallback { font-size: 14px; text-align: center; padding-top: 14px; line-height: 1.5; }
.signin-fallback a { color: var(--green); font-weight: 800; text-decoration: underline; }
.signin-back { display: flex; gap: 8px; align-items: center; font-size: 15px; font-weight: 800; color: var(--green); min-height: 44px; padding: 6px 18px; border: 1px solid #bdd8ca; border-radius: 999px; background: #fffffff0; box-shadow: 0 3px 10px #203d3608; }
.signin-back img { transition: transform .18s; }
.signin-back:hover { text-decoration: underline; text-underline-offset: 4px; background: #fff; border-color: #76a58e; }
.signin-back:hover img { transform: translateX(-3px); }
.signin-back:focus-visible { outline: 3px solid #ac4e25; outline-offset: 3px; background: white; }
@media (max-width: 560px) {
    .signin-scene { padding: 20px 16px max(28px, env(safe-area-inset-bottom)); justify-content: flex-start; gap: 20px; }
    .signin-panel { padding: 20px 16px 12px; }
    .signin-book { width: 44px; height: 44px; margin-bottom: 10px; }
    .signin-book img { width: 24px; height: 24px; }
    .signin-art { object-position: center bottom; }
    .signin-scene::before { background: #eaf8f280; }
}
@media (max-width: 360px) {
    .signin-scene { padding-inline: 12px; }
    .signin-panel { padding-inline: 12px; }
}
@media (prefers-reduced-motion: reduce) { .signin-back img, #astra-auth-frame { transition: none; } }