.classroom-utility-button {
    display: inline-flex; align-items: center; justify-content: center; gap: 6px;
    min-height: 34px; max-width: 150px; padding: 6px 9px; border: 1px solid var(--line);
    border-radius: 6px; background: var(--surface); color: var(--ink); font: inherit;
    font-size: 11px; font-weight: 700; cursor: pointer; line-height: 1.2;
    transition: background 140ms ease, border-color 140ms ease;
}
.classroom-utility-button[hidden] { display: none; }
.classroom-utility-button img { flex: 0 0 auto; }
.classroom-utility-button.is-icon { width: 34px; padding: 6px; }
.classroom-utility-button:hover { background: var(--teal-soft); border-color: var(--teal); }
.classroom-utility-button[data-state="attention"] { border-color: var(--orange, #c77219); }
.classroom-device-dialog {
    width: min(540px, calc(100vw - 28px)); max-height: min(760px, calc(100dvh - 36px));
    padding: 20px; box-sizing: border-box; overflow: auto; border: 1px solid var(--line);
    border-radius: 8px; color: var(--ink); background: var(--surface); font: inherit;
    box-shadow: 0 18px 65px #0005;
}
.classroom-device-dialog::backdrop { background: #0007; }
.classroom-device-dialog header { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.classroom-device-dialog h2 { margin: 0; font-size: 20px; }
.classroom-device-dialog label { display: grid; gap: 6px; margin-top: 14px; font-size: 14px; font-weight: 700; }
.classroom-device-dialog select { width: 100%; min-width: 0; padding: 10px; color: var(--ink); background: var(--page); border: 1px solid var(--line); border-radius: 5px; font: inherit; }
.classroom-device-dialog button { cursor: pointer; }
.classroom-device-dialog button:disabled { cursor: not-allowed; opacity: .55; }
.classroom-device-dialog [data-device-close] { flex: 0 0 34px; width: 34px; height: 34px; padding: 6px; border: 1px solid var(--line); border-radius: 5px; background: var(--page); }
.classroom-device-dialog [data-device-close]:hover { background: var(--teal-soft); }
.classroom-device-dialog small, .classroom-device-dialog p { color: var(--ink-soft); font-size: 12px; line-height: 1.5; }
.classroom-device-dialog footer { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.classroom-device-dialog footer small { flex-basis: 100%; }
.classroom-device-dialog .button { min-height: 34px; padding: 7px 10px; font-size: 12px; white-space: normal; }
.audio-device-test { display: flex; gap: 12px; align-items: center; margin: 10px 0 18px; }
.audio-device-test meter { flex: 1; min-width: 45px; height: 16px; accent-color: var(--teal); }
.classroom-device-dialog .audio-device-test .button { width: auto; flex: 0 1 55%; }
.audio-device-status { min-height: 2em; margin: 14px 0 0; }
.classroom-recovery-list section { display: grid; grid-template-columns: 1fr 1fr; gap: 5px 12px; padding: 11px 0; border-bottom: 1px solid var(--line); font-size: 12px; }
.classroom-recovery-list section > div { grid-column: 1 / -1; display: flex; flex-wrap: wrap; gap: 6px; }
.classroom-recovery-list section > span { overflow-wrap: anywhere; }
@media (max-width: 600px) {
    .classroom-utility-button { max-width: 115px; font-size: 10px; }
    .classroom-utility-button[data-classroom-recovery] { width: 34px; min-width: 34px; position: relative; }
    .classroom-utility-button[data-classroom-recovery] span { display: none; }
    .classroom-utility-button[data-classroom-recovery][data-state="attention"]::after { content: ''; position: absolute; right: 4px; top: 4px; width: 5px; height: 5px; border-radius: 50%; background: var(--orange, #c77219); }
    .classroom-device-dialog { padding: 15px; }
}