:root {
  --ink: #102b46;
  --muted: #6b7d8d;
  --blue: #0867bd;
  --cyan: #20b8d7;
  --bg: #eef4f8;
  --card: #fff;
  --line: #d8e3eb;
  --danger: #b33b42;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  color: var(--ink);
  font-family: "IBM Plex Sans Thai", "Noto Sans Thai", "Leelawadee UI", Tahoma, Arial, sans-serif;
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
button,
input,
select,
textarea {
  font-family: inherit;
}
a {
  color: inherit;
  text-decoration: none;
}
.site-header,
.viewer-header {
  height: 62px;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #061523;
  color: #fff;
}
.brand {
  font-weight: 850;
  letter-spacing: 0.01em;
}
.admin-link,
.back-link {
  font-size: 0.86rem;
  color: #b9d4e8;
}
.home-wrap,
.admin-wrap {
  max-width: 1180px;
  margin: auto;
  padding: 42px 24px 80px;
}
.hero {
  padding: 22px 0 30px;
}
.eyebrow,
.pane-kicker {
  margin: 0;
  color: var(--blue);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.16em;
}
.hero h1,
.admin-toolbar h1 {
  margin: 8px 0;
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  line-height: 1.15;
}
.hero p:not(.eyebrow) {
  color: var(--muted);
  max-width: 680px;
}
.date-group {
  margin: 24px 0 34px;
}
.date-heading {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 13px;
  color: #46647a;
  font-size: 1.06rem;
  font-weight: 800;
}
.date-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 5px #d5f3f8;
}
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
}
.topic-card {
  min-height: 180px;
  padding: 21px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 10px 30px #2448660c;
  transition: 0.2s;
}
.topic-card:hover {
  transform: translateY(-3px);
  border-color: #93cce2;
  box-shadow: 0 14px 30px #24486618;
}
.topic-index {
  font-size: 0.7rem;
  color: var(--blue);
  font-weight: 900;
  letter-spacing: 0.11em;
}
.topic-card h2 {
  margin: 13px 0 7px;
  font-size: 1.2rem;
  line-height: 1.35;
}
.topic-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.55;
}
.open-topic {
  display: block;
  margin-top: 22px;
  color: var(--blue);
  font-size: 0.82rem;
  font-weight: 850;
}
.empty-state {
  padding: 30px;
  border: 1px dashed #aac0cf;
  border-radius: 14px;
  color: var(--muted);
  text-align: center;
}
.viewer-body {
  overflow: hidden;
  background: #061523;
}
.viewer-header {
  height: 54px;
  padding: 0 20px;
}
.viewer-meta {
  display: flex;
  gap: 18px;
  color: #bdd0e1;
  font-size: 0.8rem;
}
.deck {
  position: fixed;
  inset: 54px 0 0;
}
.topic-panel {
  position: absolute;
  inset: 0;
  padding: 16px 20px 22px;
  display: grid;
  grid-template-columns: minmax(0, 70fr) minmax(360px, 30fr);
  gap: 16px;
  opacity: 0;
  visibility: hidden;
  transform: translateX(18px);
  pointer-events: none;
  transition: 0.38s ease;
  background: radial-gradient(circle at 15% 15%, #21496f, #0a1c30 45%, #061321);
}
.topic-panel.active {
  opacity: 1;
  visibility: visible;
  transform: none;
  pointer-events: auto;
}
.pane {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr) auto;
  overflow: hidden;
  border-radius: 15px;
  background: #edf4fa;
  box-shadow: 0 20px 55px #0000004d;
}
.pane-head {
  min-height: 65px;
  padding: 10px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  background: #fff;
  border-bottom: 1px solid var(--line);
}
.pane-head h1,
.pane-head h2 {
  margin: 4px 0 0;
  color: #0d294b;
  font-size: 0.9rem;
  line-height: 1.25;
}
.icon-button {
  width: 35px;
  height: 35px;
  border: 0;
  border-radius: 50%;
  background: #e5f0fa;
  color: #0d619e;
  font-size: 1.05rem;
  cursor: pointer;
}
.tab-bar {
  min-height: 45px;
  display: flex;
  align-items: end;
  gap: 4px;
  padding: 7px 7px 0;
  overflow-x: auto;
  background: #dfe9f3;
  scrollbar-width: thin;
}
.tab {
  flex: 1 0 125px;
  max-width: 240px;
  height: 38px;
  padding: 0 10px;
  border: 1px solid #b9c9d8;
  border-bottom: 0;
  border-radius: 9px 9px 0 0;
  background: #cbd9e6;
  color: #435c73;
  font-size: 0.7rem;
  font-weight: 800;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  cursor: pointer;
}
.tab.active {
  position: relative;
  background: #fff;
  color: #075fae;
  border-color: #aabccc;
}
.tab.active:after {
  content: "";
  position: absolute;
  left: 10%;
  right: 10%;
  bottom: 0;
  height: 3px;
  background: var(--cyan);
  border-radius: 3px 3px 0 0;
}
.visual-stage,
.pdf-stage {
  position: relative;
  min-height: 0;
  overflow: hidden;
  background: #eaf1f7;
}
.visual-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  opacity: 0;
  visibility: hidden;
  transform: scale(0.985);
  transition: 0.28s;
}
.visual-image.active {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.pdf-stage {
  background: #626c76;
}
.pdf-stage iframe {
  width: 100%;
  height: 100%;
  display: none;
  border: 0;
  background: #656e77;
}
.pdf-stage iframe.active {
  display: block;
}
.pdf-loading {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #fff;
  background: #626c76;
  pointer-events: none;
}
.pdf-stage.loaded .pdf-loading {
  opacity: 0;
}
.missing-media {
  display: grid;
  place-items: center;
  height: 100%;
  color: var(--muted);
}
.pane-foot {
  height: 31px;
  padding: 0 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  background: #fff;
  border-top: 1px solid var(--line);
  color: #60758a;
  font-size: 0.63rem;
}
.pane-foot strong {
  max-width: 48%;
  color: #0b64a8;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.viewer-nav {
  position: fixed;
  z-index: 40;
  left: 35%;
  bottom: 8px;
  translate: -50%;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 9px;
  border: 1px solid #ffffff29;
  border-radius: 999px;
  background: #03101de6;
}
.viewer-nav > button {
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 50%;
  background: #173c63;
  color: #fff;
  cursor: pointer;
}
.dots {
  display: flex;
  gap: 8px;
}
.dots button {
  width: 8px;
  height: 8px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: #647f9b;
  cursor: pointer;
}
.dots button.active {
  background: var(--cyan);
  transform: scale(1.4);
}
.lightbox {
  position: fixed;
  z-index: 100;
  inset: 0;
  display: none;
  place-items: center;
  padding: 14px;
  background: #000000f7;
}
.lightbox.open {
  display: grid;
}
.lightbox img {
  max-width: 98vw;
  max-height: 96vh;
  object-fit: contain;
}
.lightbox button {
  position: absolute;
  right: 16px;
  top: 16px;
  width: 44px;
  height: 44px;
  border: 1px solid #74899d;
  border-radius: 50%;
  background: #12263d;
  color: #fff;
  font-size: 1.4rem;
  cursor: pointer;
}
.admin-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: 20px;
  margin-bottom: 20px;
}
.admin-grid {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 18px;
}
.admin-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  box-shadow: 0 10px 30px #2448660c;
}
.admin-card h2 {
  margin: 0 0 14px;
}
.topic-list {
  display: grid;
  gap: 8px;
}
.topic-list button {
  padding: 12px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #f8fbfd;
  color: var(--ink);
  cursor: pointer;
}
.topic-list button.active {
  border-color: var(--cyan);
  background: #e9f9fc;
}
.topic-list small {
  display: block;
  color: var(--muted);
  margin-bottom: 3px;
}
.form-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.form-heading h2 {
  margin: 0 0 14px;
}
label {
  display: block;
  margin: 13px 0;
  font-size: 0.82rem;
  font-weight: 800;
}
input,
textarea {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 11px;
  border: 1px solid #c8d7e2;
  border-radius: 8px;
  background: #fff;
  font: inherit;
  color: var(--ink);
}
.check {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
}
.check input {
  width: auto;
  margin: 0;
}
.primary,
.secondary,
.danger-outline {
  padding: 10px 15px;
  border-radius: 8px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
.primary {
  border: 0;
  background: var(--blue);
  color: #fff;
}
.secondary {
  border: 1px solid #9bcfe0;
  background: #e8f8fb;
  color: #056589;
}
.danger-outline {
  border: 1px solid #df9ca0;
  background: #fff;
  color: var(--danger);
}
.notice {
  margin-bottom: 15px;
  padding: 11px 14px;
  border-radius: 9px;
  background: #dff4e8;
  color: #17643c;
}
.media-section {
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.media-section h3 {
  margin: 0 0 10px;
}
.media-row {
  display: grid;
  grid-template-columns: 1fr 1fr 90px auto;
  gap: 7px;
  align-items: center;
  margin: 8px 0;
}
.media-row input {
  margin: 0;
}
.media-row .delete {
  border: 1px solid #df9ca0;
  background: #fff;
  color: var(--danger);
  border-radius: 7px;
  padding: 9px;
  cursor: pointer;
}
.upload-form {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 75px 1.2fr auto;
  gap: 7px;
  align-items: end;
  margin-top: 12px;
}
.upload-form input {
  margin: 0;
}
.upload-form button {
  white-space: nowrap;
}
@media (max-width: 980px) {
  .topic-panel {
    grid-template-columns: minmax(0, 62fr) minmax(340px, 38fr);
    padding: 10px;
    gap: 9px;
  }
  .viewer-nav {
    left: 31%;
  }
  .admin-grid {
    grid-template-columns: 1fr;
  }
  .upload-form {
    grid-template-columns: 1fr 1fr;
  }
  .media-row {
    grid-template-columns: 1fr 1fr;
  }
  .viewer-meta {
    display: none;
  }
}
@media (max-aspect-ratio: 4/3) {
  .topic-panel {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(0, 58fr) minmax(0, 42fr);
  }
  .viewer-nav {
    left: 50%;
  }
}
@media (max-width: 600px) {
  .home-wrap,
  .admin-wrap {
    padding: 28px 16px;
  }
  .site-header {
    padding: 0 16px;
  }
  .upload-form {
    grid-template-columns: 1fr;
  }
  .back-link {
    font-size: 0.72rem;
  }
}
:root {
  --viewer-control-bg: #173c63;
}
.viewer-body .viewer-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}
.viewer-body .auto-render-control {
  display: flex;
  align-items: center;
  gap: 5px;
  color: #d2e3f0;
  font-size: 0.72rem;
  white-space: nowrap;
}
.viewer-body .auto-render-control input {
  display: inline-block;
  width: 58px;
  margin: 0;
  padding: 5px 6px;
  border: 1px solid #52718b;
  border-radius: 6px;
  background: #102b46;
  color: #fff;
  font: inherit;
  text-align: center;
}
.viewer-body .auto-render-control button {
  padding: 6px 9px;
  border: 1px solid #52718b;
  border-radius: 6px;
  background: var(--viewer-control-bg);
  color: #fff;
  font: inherit;
  font-size: 0.7rem;
  cursor: pointer;
}
.viewer-body .auto-render-control button:hover {
  background: #205685;
}
@media (max-width: 600px) {
  .viewer-body .viewer-actions {
    gap: 7px;
  }
  .viewer-body .auto-render-control label,
  .viewer-body .auto-render-control span {
    display: none;
  }
  .viewer-body .auto-render-control input {
    width: 50px;
  }
  .viewer-body .auto-render-control button {
    padding: 6px 7px;
  }
}
.auth-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.8rem;
}
.auth-actions a {
  color: #b9d4e8;
}
.auth-wrap {
  display: grid;
  place-items: start center;
  min-height: calc(100vh - 62px);
  padding: 70px 20px;
}
.auth-card {
  width: min(460px, 100%);
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: 0 15px 40px #24486612;
}
.auth-card h1 {
  margin: 8px 0 22px;
}
.auth-card .primary {
  width: 100%;
  margin-top: 9px;
}
.auth-help {
  margin: 18px 0 0;
  font-size: 0.82rem;
}
.auth-error,
.auth-success {
  padding: 10px 12px;
  margin-bottom: 14px;
  border-radius: 8px;
}
.auth-error {
  background: #fde5e5;
  color: #8b2228;
}
.auth-success {
  background: #dff4e8;
  color: #17643c;
}
.button-link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}
.backup-card {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: center;
  margin-bottom: 18px;
}
.backup-card h2 {
  margin: 7px 0 4px;
}
.backup-card p {
  margin: 0;
}
.backup-actions {
  display: flex;
  align-items: center;
  gap: 9px;
}
.restore-upload {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 10px 15px;
  border: 1px solid #9bcfe0;
  border-radius: 8px;
  background: #e8f8fb;
  color: #056589;
  font-weight: 800;
  cursor: pointer;
}
.restore-upload input {
  display: none;
}
.backup-warning {
  grid-column: 1/-1;
  color: #8b5c1b;
  font-size: 0.78rem;
}
.users-card {
  margin-top: 18px;
}
.user-form {
  display: grid;
  grid-template-columns: 1fr 1fr 150px 1fr auto;
  gap: 8px;
  align-items: end;
}
.user-form input,
.user-form select {
  margin: 0;
}
.user-row {
  display: grid;
  grid-template-columns: 1.5fr 140px 100px auto auto auto;
  gap: 8px;
  align-items: center;
  padding: 10px 0;
  border-top: 1px solid var(--line);
}
.user-row input,
.user-row select {
  margin: 0;
  padding: 8px;
}
.user-row strong,
.user-row small {
  display: block;
}
.user-row small {
  color: var(--muted);
  margin-top: 3px;
}
.user-badge {
  color: #8b5c1b;
  font-size: 0.72rem;
}
.media-row {
  grid-template-columns: 1.5fr 1fr 90px auto auto;
}
.media-row small {
  color: var(--muted);
  font-size: 0.72rem;
  overflow-wrap: anywhere;
}
@media (max-width: 980px) {
  .backup-card {
    grid-template-columns: 1fr;
  }
  .backup-actions {
    flex-wrap: wrap;
  }
  .user-form {
    grid-template-columns: 1fr 1fr;
  }
  .user-row {
    grid-template-columns: 1fr 1fr;
  }
  .user-row .user-badge {
    grid-column: 1/-1;
  }
}
@media (max-width: 600px) {
  .auth-actions {
    gap: 8px;
  }
  .auth-actions span {
    display: none;
  }
  .backup-actions {
    display: grid;
  }
  .user-form {
    grid-template-columns: 1fr;
  }
  .user-row {
    grid-template-columns: 1fr;
  }
  .user-row .check {
    justify-content: flex-start;
  }
}
.pane-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}
.icon-button:disabled {
  opacity: 0.42;
  cursor: not-allowed;
}
.pdf-stage iframe[data-document-type="markdown"] {
  background: #fff;
}
.music-player {
  position: fixed;
  z-index: 80;
  left: 50%;
  bottom: 14px;
  width: min(720px, calc(100vw - 28px));
  translate: -50%;
  padding: 10px 13px 8px;
  border: 1px solid #8ca9bd;
  border-radius: 14px;
  background: #061523f2;
  color: #fff;
  box-shadow: 0 14px 40px #0008;
  backdrop-filter: blur(8px);
}
.music-player-main {
  display: flex;
  align-items: center;
  gap: 8px;
}
.music-player-controls {
  display: flex;
  align-items: center;
  gap: 4px;
}
.music-control,
.music-option {
  width: 32px;
  height: 32px;
  padding: 0;
  border: 1px solid #52718b;
  border-radius: 50%;
  background: #173c63;
  color: #fff;
  font: inherit;
  cursor: pointer;
}
.music-control:hover,
.music-option:hover,
.music-option.active {
  background: #0b78a8;
  border-color: #63d1e5;
}
.music-play {
  width: 38px;
  height: 38px;
  background: var(--blue);
  font-size: 1.05rem;
}
.music-track-info {
  min-width: 0;
  flex: 1;
  padding: 0 6px;
}
.music-track-info strong,
.music-track-info small {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.music-track-info strong {
  font-size: 0.82rem;
}
.music-track-info small {
  margin-top: 2px;
  color: #b9d4e8;
  font-size: 0.68rem;
}
.music-volume {
  width: 82px;
  accent-color: var(--cyan);
}
.music-progress-row {
  display: grid;
  grid-template-columns: 38px 1fr 38px;
  align-items: center;
  gap: 8px;
  margin-top: 5px;
  color: #b9d4e8;
  font-size: 0.65rem;
}
.music-progress-row input {
  width: 100%;
  margin: 0;
  accent-color: var(--cyan);
}
@media (max-width: 600px) {
  .music-player {
    bottom: 8px;
    padding: 8px 9px 7px;
  }
  .music-player-main {
    gap: 5px;
  }
  .music-track-info {
    padding: 0 3px;
  }
  .music-volume {
    width: 56px;
  }
  .music-control,
  .music-option {
    width: 29px;
    height: 29px;
    font-size: 0.78rem;
  }
  .music-play {
    width: 35px;
    height: 35px;
  }
  .music-progress-row {
    margin-top: 3px;
  }
}
.music-admin-card {
  margin-bottom: 18px;
}
.music-admin-list {
  display: grid;
  gap: 8px;
  margin-top: 14px;
}
.music-admin-row {
  display: grid;
  grid-template-columns:
    minmax(160px, 1.5fr) 85px 90px minmax(170px, 1.3fr)
    auto auto;
  gap: 8px;
  align-items: center;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}
.music-admin-row input {
  margin: 0;
  padding: 8px;
}
.music-admin-row small {
  display: block;
  color: var(--muted);
  font-size: 0.72rem;
  overflow-wrap: anywhere;
}
.music-admin-row .check {
  margin: 0;
  justify-content: center;
  white-space: nowrap;
}
.music-admin-row .check input {
  width: auto;
  margin: 0;
}
.music-upload-form {
  display: grid;
  grid-template-columns: 1.5fr 85px 90px 1.4fr auto;
  gap: 8px;
  align-items: end;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}
.music-upload-form input {
  margin: 0;
}
.music-upload-form .check {
  margin: 0;
  align-self: center;
  white-space: nowrap;
}
@media (max-width: 980px) {
  .music-admin-row {
    grid-template-columns: 1fr 85px 90px;
  }
  .music-admin-row small {
    grid-column: 1/-1;
  }
  .music-upload-form {
    grid-template-columns: 1fr 85px 90px;
  }
  .music-upload-form input[type="file"],
  .music-upload-form button {
    grid-column: span 2;
  }
}
@media (max-width: 600px) {
  .music-admin-row,
  .music-upload-form {
    grid-template-columns: 1fr;
  }
  .music-admin-row .check,
  .music-upload-form .check {
    justify-content: flex-start;
  }
  .music-upload-form input[type="file"],
  .music-upload-form button {
    grid-column: auto;
  }
}
.music-player {
  position: static;
  left: auto;
  bottom: auto;
  translate: none;
  width: auto;
  max-width: 240px;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  color: #fff;
  box-shadow: none;
  backdrop-filter: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.music-player[hidden] {
  display: none;
}
.music-track-title {
  display: block;
  max-width: 145px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: #e9f6ff;
  font-size: 0.76rem;
}
.music-player .music-control {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  font-size: 0.75rem;
}
.music-player .music-play {
  width: 31px;
  height: 31px;
  font-size: 0.9rem;
}
.music-player audio {
  display: none;
}
.site-header,
.viewer-header,
.news-viewer-header,
.keyword-viewer-header {
  gap: 12px;
}
.site-header > .music-player,
.viewer-header > .music-player,
.news-viewer-header > .music-player,
.keyword-viewer-header > .music-player {
  margin-left: auto;
}
.music-player + .auth-actions,
.music-player + .viewer-meta,
.music-player + .viewer-actions,
.music-player + .news-viewer-actions,
.music-player + .keyword-viewer-actions {
  margin-left: 0;
}
@media (max-width: 980px) {
  .music-player {
    max-width: 190px;
  }
  .music-track-title {
    max-width: 95px;
  }
  .site-header,
  .viewer-header,
  .news-viewer-header,
  .keyword-viewer-header {
    padding-left: 14px;
    padding-right: 14px;
    gap: 7px;
  }
}
@media (max-width: 600px) {
  .music-player {
    gap: 3px;
  }
  .music-track-title {
    display: none;
  }
  .music-player .music-control {
    width: 26px;
    height: 26px;
  }
  .music-player .music-play {
    width: 29px;
    height: 29px;
  }
  .site-header .brand {
    max-width: 42%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .auth-actions {
    gap: 7px;
  }
  .auth-actions a {
    font-size: 0.68rem;
  }
}

/* Desktop alignment for Home and Admin */
.site-header > .auth-actions {
  margin-left: auto;
}

/* Responsive refinements for narrow screens. */
html,
body {
  max-width: 100%;
  overflow-x: hidden;
}

@media (max-width: 760px) {
  .site-header {
    min-height: 56px;
    height: auto;
    padding: 9px 12px;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
  }

  .site-header > .brand {
    min-width: 0;
    flex: 1 1 0;
  }

  .site-header > .music-player {
    margin-left: 0;
    max-width: none;
  }

  .site-header > .auth-actions {
    width: 100%;
    justify-content: flex-end;
    flex-wrap: wrap;
  }

  .viewer-header {
    height: auto;
    min-height: 54px;
    padding: 8px 12px;
    flex-wrap: wrap;
    gap: 7px;
  }

  .viewer-header .content-viewer-brand {
    min-width: 0;
    flex: 1 1 0;
  }

  .viewer-header > .music-player {
    margin-left: 0;
  }

  .viewer-header .viewer-actions {
    width: 100%;
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: 7px;
  }

  .viewer-body {
    overflow: hidden;
  }

  .deck {
    position: relative;
    inset: auto;
    height: calc(100vh - 112px);
    min-height: 440px;
  }

  .topic-panel {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(240px, 56fr) minmax(250px, 44fr);
    gap: 8px;
    padding: 8px 8px 46px;
  }

  .viewer-nav {
    left: 50%;
  }
}

@media (max-width: 480px) {
  .topic-panel {
    grid-template-rows: minmax(220px, 54fr) minmax(250px, 46fr);
    gap: 6px;
    padding: 6px 6px 44px;
  }

  .pane-head h1,
  .pane-head h2 {
    font-size: 0.82rem;
  }

  .tab {
    flex-basis: 105px;
    min-width: 105px;
  }
}

/* In-page PDF.js canvas surface used by Topic, Keyword and Sharing. */
.sharing-main-stage .portal-pdf-frame,
.pdf-stage .portal-pdf-frame,
.document-workspace-stage .portal-pdf-frame {
  position: absolute;
  inset: 0;
  display: none;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  overflow: auto;
  padding: 12px;
  background: #e8edf2;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
}
.sharing-main-stage .portal-pdf-frame.active,
.pdf-stage .portal-pdf-frame.active,
.document-workspace-stage .portal-pdf-frame.active {
  display: block;
}
.portal-pdf-pages {
  display: grid;
  gap: 12px;
  justify-items: center;
  width: 100%;
  min-width: 0;
}
.portal-pdf-page {
  width: min(100%, 1400px);
  max-width: 100%;
  background: #fff;
  box-shadow: 0 2px 12px #1b2b3a36;
}
.portal-pdf-page canvas {
  display: block;
  width: 100%;
  height: 100%;
}
/* Pages not drawn yet (lazy rendering): keep the page's shape with a soft placeholder. */
.portal-pdf-page:not(.is-rendered) {
  background: linear-gradient(100deg, #fff 40%, #f1f5f9 50%, #fff 60%) 0 0 / 200% 100%;
  animation: portal-pdf-placeholder 1.4s linear infinite;
}
@keyframes portal-pdf-placeholder {
  to { background-position: -200% 0; }
}
@media (prefers-reduced-motion: reduce) {
  .portal-pdf-page:not(.is-rendered) { animation: none; }
}
.portal-pdf-error {
  display: grid;
  place-items: center;
  min-height: 100%;
  padding: 24px;
  color: #8b1e3f;
  text-align: center;
}

@media (orientation: landscape) and (max-height: 520px) {
  .viewer-header {
    min-height: 46px;
    height: 46px;
    padding: 0 10px;
  }
  .deck {
    inset: 46px 0 0;
  }
  .topic-panel {
    grid-template-columns: minmax(0,64fr) minmax(260px,36fr);
    gap: 8px;
    padding: 8px 10px 16px;
  }
  .pane-head {
    min-height: 48px;
    padding: 7px 10px;
  }
  .pane-head h1,
  .pane-head h2 {
    font-size: 0.78rem;
  }
  .tab-bar {
    min-height: 37px;
    padding-top: 4px;
  }
  .tab {
    height: 31px;
  }
}