.room-usage-main {
  width: min(1700px, calc(100% - 48px));
  margin: 30px auto 56px;
  min-height: calc(100vh - 230px);
}
.room-usage-main > .teacher-back-link { display: inline-block; margin-bottom: 22px; }
.room-usage-heading { text-align: center; margin: 0 auto 28px; }
.room-usage-heading > p:first-child { color: #667085; margin: 0 0 8px; }
.room-usage-heading h1 { margin: 0; color: #20243a; font-size: clamp(30px, 4vw, 48px); }
.room-usage-heading > p:last-child { color: #667085; margin: 8px 0 0; }
.room-usage-filters {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(360px, 1.5fr);
  align-items: center;
  gap: 20px;
  padding: 20px 22px;
  border: 1px solid #d9dee7;
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 8px 26px rgb(31 41 55 / 5%);
}
.room-usage-filters label { display: grid; gap: 7px; color: #475467; font-size: 14px; font-weight: 600; }
.room-usage-filters select { width: 100%; min-width: 0; max-width: none; height: 48px; padding: 0 14px; border: 1px solid #d0d5dd; border-radius: 10px; background: #fff; color: #344054; font: inherit; }
.room-usage-filters select:disabled { background: #f2f4f7; color: #98a2b3; }
.room-usage-period-note { display: grid; gap: 4px; color: #667085; font-size: 13px; }
.room-usage-period-note strong { color: #a94f00; font-size: 19px; }
.room-usage-location-field { width: 100%; max-width: none; }
.room-usage-message { min-height: 24px; margin: 16px 0; text-align: center; color: #667085; }
.room-usage-message[hidden] { display: none; }
.room-usage-message.is-loading::before { content: ""; display: inline-block; width: 12px; height: 12px; margin-right: 9px; border: 2px solid #f6d1a4; border-top-color: #f7931e; border-radius: 50%; vertical-align: -2px; animation: room-usage-spin .8s linear infinite; }
@keyframes room-usage-spin { to { transform: rotate(360deg); } }
.room-usage-result { padding: 20px; overflow: hidden; border: 1px solid #d9dee7; border-radius: 18px; background: #fff; }
.room-usage-result-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 16px; }
.room-usage-result h2 { margin: 0; color: #a94f00; font-size: 20px; }
.room-usage-export-button { display: inline-flex; align-items: center; justify-content: center; gap: 7px; min-height: 42px; padding: 0 18px; border: 0; border-radius: 999px; background: #f0a13b; color: #382300; font: 600 14px Sarabun, sans-serif; cursor: pointer; }
.room-usage-export-button:disabled { opacity: .6; cursor: wait; }
.room-usage-export-button .material-symbols-rounded { font-size: 19px; }
.room-usage-result .schedule-table-wrap { overflow-x: auto; }
@media (max-width: 760px) {
  .room-usage-main { width: min(100% - 24px, 1700px); margin-top: 20px; }
  .room-usage-filters { grid-template-columns: 1fr; gap: 16px; padding: 14px; }
  .room-usage-result { padding: 12px; }
  .room-usage-result-heading { align-items: flex-start; flex-direction: column; }
}