:root {
  color-scheme: dark;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", Helvetica, Arial, sans-serif;
  --bg: #071421;
  --surface: rgba(9, 23, 42, 0.88);
  --surface-soft: rgba(10, 30, 53, 0.9);
  --text: #eef6ff;
  --muted: #9bb7d4;
  --accent: #5f97ff;
  --accent-2: #57f4f1;
  --border: rgba(255,255,255,0.1);
  --shadow: 0 20px 70px rgba(0, 0, 0, 0.24);
  --preview-main-width: 60%;
  --preview-handle-width: 12px;
}
* {
  box-sizing: border-box;
}
html, body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(circle at top left, rgba(87, 154, 255, 0.18), transparent 22%),
              radial-gradient(circle at bottom right, rgba(72, 233, 220, 0.13), transparent 24%),
              linear-gradient(180deg, #05111f 0%, #071421 100%);
  color: var(--text);
}
body {
  padding: 20px;
}
.app-shell {
  max-width: 1180px;
  margin: 0 auto;
}
.site-header {
  display: grid;
  gap: 18px;
  padding: 24px 28px;
  border-radius: 28px;
  background: rgba(11, 24, 45, 0.95);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: var(--shadow);
}
.site-header .eyebrow {
  margin: 0 0 10px;
  color: var(--accent-2);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  font-size: 0.87rem;
}
.site-header h1 {
  margin: 0;
  font-size: clamp(2.5rem, 4vw, 3.6rem);
  line-height: 1.05;
}
.site-header p {
  margin: 12px 0 0;
  max-width: 760px;
  color: #c2d4f2;
  font-size: 1rem;
  line-height: 1.8;
}
.header-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  padding: 12px 18px;
  border-radius: 999px;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}
.button-small {
  padding: 10px 14px;
  font-size: 0.9rem;
}
.button-xsmall {
  padding: 6px 12px;
  font-size: 0.82rem;
}
.button:hover {
  transform: translateY(-1px);
}
.button-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
  box-shadow: 0 18px 40px rgba(95, 151, 255, 0.22);
}
.button-secondary {
  background: rgba(255,255,255,0.08);
  color: var(--text);
  border-color: rgba(255,255,255,0.12);
}
.feature-panels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin: 22px 0;
}
.feature-card {
  padding: 20px;
  border-radius: 24px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.16);
}
.feature-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: rgba(255,255,255,0.08);
  margin-bottom: 16px;
  font-size: 1.35rem;
}
.feature-card h2 {
  margin: 0 0 10px;
  font-size: 1.15rem;
}
.feature-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}
.section {
  margin-top: 28px;
}
.section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 16px;
}
.section-title h2 {
  margin: 0;
  font-size: 1.85rem;
}
.section-label {
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.85rem;
  color: var(--accent-2);
}
.home-nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 16px 0 24px;
}
.home-nav-links .nav-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}
.home-nav-links .nav-link:hover {
  transform: translateY(-1px);
  background: rgba(95,151,255,0.14);
  border-color: rgba(95,151,255,0.28);
}
.skilltips-grid,
.skilltips-detail-grid {
  display: grid;
  gap: 16px;
}
.skilltips-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-bottom: 18px;
}
.skill-card,
.skill-detail-card {
  padding: 20px;
  border-radius: 24px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 18px 40px rgba(0,0,0,0.12);
}
.skill-card {
  display: grid;
  gap: 14px;
}
.skill-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: rgba(255,255,255,0.08);
  font-size: 1.4rem;
}
.skill-card h4,
.skill-detail-card h4 {
  margin: 0;
}
.skill-card p,
.skill-detail-card p,
.skill-detail-card ul {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}
.skill-detail-card ul {
  padding-left: 18px;
}
.skill-detail-card li {
  margin-bottom: 10px;
}
.skill-card .button {
  justify-self: start;
}
.skilltips-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}
.skillnav-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}
.skillnav-link:hover {
  transform: translateY(-1px);
  background: rgba(95,151,255,0.14);
  border-color: rgba(95,151,255,0.28);
}
.skilltips-accordion details {
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 20px;
  background: rgba(255,255,255,0.04);
  padding: 16px 18px;
}
.skilltips-accordion summary {
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  margin-bottom: 12px;
  list-style: none;
}
.skilltips-accordion summary::-webkit-details-marker {
  display: none;
}
.skilltips-accordion details[open] {
  background: rgba(255,255,255,0.08);
}
.skilltips-accordion p,
.skilltips-accordion .resource-links {
  margin: 0 0 12px;
  color: var(--muted);
}
.skilltips-accordion .resource-links {
  padding-left: 18px;
}
.skilltips-accordion .resource-links li {
  margin-bottom: 8px;
}
.skilltips-accordion .resource-links a {
  color: #9ecbff;
  text-decoration: none;
}
.skilltips-accordion .resource-links a:hover {
  text-decoration: underline;
}
.card-grid,
.library-grid,
.audio-list,
.tips-grid,
.plan-items {
  display: grid;
  gap: 16px;
}
.card-grid {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}
.featured-card,
.library-card,
.audio-card,
.panel-card,
.tip-card {
  padding: 22px;
  border-radius: 24px;
  background: var(--surface);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 18px 40px rgba(0,0,0,0.12);
}
.featured-card h3,
.library-card h3,
.audio-card h3,
.panel-card h3,
.tip-card h4 {
  margin: 0 0 12px;
}
.featured-card p,
.library-card p,
.audio-card p,
.panel-card p,
.tip-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}
.featured-card .tag,
.library-card .tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 14px;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  color: #fff;
  font-size: 0.82rem;
}
.featured-card .actions,
.library-card .group-actions,
.audio-card .audio-actions,
.notes-panel .note-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.featured-card .actions button {
  margin: 0;
}

.library-section {
  padding: 22px;
  border-radius: 28px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
}
.library-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.search-box input {
  width: 320px;
  max-width: 100%;
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: var(--text);
}
.search-box input:focus {
  outline: none;
  border-color: rgba(95,151,255,0.9);
  box-shadow: 0 0 0 4px rgba(95,151,255,0.12);
}
.library-toolbar {
  display: grid;
  gap: 18px;
  margin: 18px 0 24px;
}
.recent-panel,
.hint-panel {
  padding: 18px;
  border-radius: 20px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
}
.recent-panel h3 {
  margin: 0 0 12px;
}
.recent-panel ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.recent-panel li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 0.95rem;
}
.recent-panel li:last-child {
  margin-bottom: 0;
}
.recent-panel a {
  color: #9ecbff;
  text-decoration: none;
}
.library-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}
.resource-group {
  margin-top: 12px;
}
.resource-group:first-child {
  margin-top: 0;
}
.resource-group-title {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
  padding-left: 2px;
}
.library-card .resource-item {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 10px;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.06);
}
.library-card .resource-item + .resource-item {
  margin-top: 4px;
}
.resource-name {
  font-size: 0.9rem;
  color: var(--text);
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.resource-item-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
}
.resource-item-actions button,
.resource-item-actions a {
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 0.8rem;
}
.resource-item-actions a {
  color: #fff;
  background: rgba(255,255,255,0.07);
  text-decoration: none;
}
.resource-item-actions button {
  color: #fff;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.1);
  cursor: pointer;
}
.viewer-section.hidden {
  display: none;
}
.viewer-grid {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(330px, 1fr);
  gap: 18px;
}
.viewer-left,
.viewer-right {
  border-radius: 24px;
  background: var(--surface);
  border: 1px solid rgba(255,255,255,0.08);
}
.viewer-left {
  display: flex;
  flex-direction: column;
  min-height: 640px;
  overflow: hidden;
}
.viewer-right {
  display: flex;
  flex-direction: column;
  min-height: 720px;
}
.viewer-panel {
  display: grid;
  gap: 18px;
  padding: 22px;
  flex: 1;
}
.viewer-audio-list,
.viewer-parse-list {
  display: grid;
  gap: 14px;
  max-height: calc(100vh - 340px);
  overflow: auto;
}
.viewer-right {
  overflow: auto;
}
.viewer-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 18px 22px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
#viewerTitle {
  margin: 0;
  font-size: 1rem;
  color: #fff;
}
.viewer-buttons {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
#pdfViewer {
  flex: 1;
  width: 100%;
  min-height: 520px;
  border: none;
  background: #0b1725;
}
.viewer-note {
  padding: 16px 22px;
  color: var(--muted);
  font-size: 0.95rem;
  border-top: 1px solid rgba(255,255,255,0.08);
}
.viewer-panel h3 {
  margin: 0;
  font-size: 1.15rem;
}
.viewer-panel-description {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
  font-size: 0.95rem;
}
.viewer-section-group {
  display: grid;
  gap: 12px;
}
.viewer-section-group h4 {
  margin: 0;
  font-size: 1rem;
  color: #fff;
}
.viewer-audio-card,
.parse-item {
  padding: 16px;
  border-radius: 18px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
}
.viewer-audio-card h4 {
  margin: 0 0 10px;
  font-size: 1rem;
}
.parse-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}
.parse-item span {
  color: var(--text);
  font-size: 0.95rem;
}
.viewer-audio-card audio {
  width: 100%;
}
.practice-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: 18px;
  align-items: start;
}
.panel-card {
  background: var(--surface);
}
.audio-list {
  grid-template-columns: 1fr;
  max-height: 520px;
  overflow: auto;
  padding-right: 4px;
}
.audio-card {
  display: grid;
  gap: 10px;
}
.audio-card p {
  font-size: 0.94rem;
}
.audio-card audio {
  width: 100%;
}
.notes-panel {
  display: grid;
  grid-template-rows: auto minmax(240px, 1fr) auto auto;
  gap: 14px;
  min-height: 520px;
}
.notes-panel textarea {
  width: 100%;
  min-height: 240px;
  max-height: 1420px;
  resize: vertical;
  padding: 16px;
  border-radius: 18px;
  border: 1px solid rgba(255,255,255,0.12);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  font-size: 0.95rem;
  line-height: 1.6;
}
.notes-panel textarea:focus {
  outline: none;
  border-color: rgba(95,151,255,0.9);
  box-shadow: 0 0 0 3px rgba(95,151,255,0.12);
}
.note-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: flex-start;
}
.note-actions .button {
  min-width: 0;
}
.notes-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.plan-box {
  padding: 18px;
  border-radius: 18px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
}
.plan-box h4 {
  margin-top: 0;
}
.plan-items {
  list-style: none;
  margin: 0;
  padding: 0;
}
.plan-items li {
  margin-bottom: 10px;
}
.plan-items input[type="checkbox"] {
  margin-right: 10px;
}
.tips-grid {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}
.tip-card {
  background: rgba(255,255,255,0.05);
}
.tip-card h4 {
  margin-bottom: 10px;
}
.tip-card p {
  margin: 0;
}
.preview-shell {
  min-height: 100vh;
  padding: 20px;
  background: radial-gradient(circle at top left, rgba(87, 154, 255, 0.16), transparent 18%),
              radial-gradient(circle at bottom right, rgba(72, 233, 220, 0.12), transparent 22%),
              linear-gradient(180deg, #05111f 0%, #071421 100%);
  display: flex;
  flex-direction: column;
}
.preview-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
  margin-bottom: 16px;
}
.preview-headline {
  flex: 1 1 auto;
  min-width: 0;
}
.preview-title-block {
  flex: 1 1 auto;
  min-width: 0;
}
.preview-header .eyebrow {
  margin: 0 0 6px;
  color: var(--accent-2);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.85rem;
}
.preview-header h1 {
  margin: 0;
  font-size: clamp(1.8rem, 2.2vw, 2.7rem);
}
.preview-header p {
  margin: 6px 0 0;
  max-width: 760px;
  color: var(--muted);
}
.preview-toolbar {
  display: flex;
  flex: 1 1 auto;
  justify-content: flex-end;
  align-items: center;
  gap: 14px;
  min-width: 0;
}
.preview-shortcuts {
  display: flex;
  flex-wrap: nowrap;
  justify-content: flex-end;
  align-items: center;
  gap: 14px;
  max-width: none;
  overflow-x: auto;
  padding-bottom: 2px;
}
.preview-subtitle {
  grid-column: 1 / -1;
  margin: 0;
}
.preview-shortcut-group {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 18px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 10px 24px rgba(0,0,0,0.16);
}
.preview-shortcut-group-title {
  font-size: 0.92rem;
  color: var(--muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.preview-shortcut-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preview-shortcut-link {
  border: 1px solid rgba(255,255,255,0.14);
  background: rgba(255,255,255,0.08);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}
.preview-shortcut-link:hover {
  transform: translateY(-1px);
  border-color: rgba(95,151,255,0.7);
  background: rgba(95,151,255,0.18);
}
.preview-shortcut-link.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-color: transparent;
  color: #fff;
}
.preview-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.preview-grid {
  display: grid;
  grid-template-columns: minmax(320px, var(--preview-main-width)) var(--preview-handle-width) minmax(320px, 1fr);
  grid-template-rows: minmax(0, 1fr);
  grid-template-areas: "main handle parse";
  gap: 18px;
  align-items: stretch;
  flex: 1;
  min-height: 0;
}
body[data-preview-layout="split-64"] .preview-grid {
  grid-template-columns: minmax(0, 1.6fr) minmax(320px, 1fr);
}
body[data-preview-layout="split-55"] .preview-grid {
  grid-template-columns: minmax(0, 1.22fr) minmax(320px, 1fr);
}
.preview-column {
  display: grid;
  gap: 18px;
  min-height: 0;
  height: 100%;
}
.preview-column.preview-main {
  grid-area: main;
}
.preview-resizer {
  grid-area: handle;
  align-self: stretch;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  position: relative;
  cursor: col-resize;
  transition: background 0.15s ease, border-color 0.15s ease;
  touch-action: none;
}
.preview-resizer::after {
  content: '';
  position: absolute;
  top: 16px;
  bottom: 16px;
  left: 50%;
  width: 2px;
  border-radius: 999px;
  background: rgba(255,255,255,0.5);
  transform: translateX(-50%);
}
.preview-resizer:is(:hover, :focus-visible),
.preview-resizer.dragging {
  background: rgba(95,151,255,0.25);
  border-color: rgba(95,151,255,0.5);
}
.preview-resizer.dragging::after {
  background: #fff;
}
.preview-column.preview-parse {
  grid-area: parse;
}
.preview-parse {
  min-height: 0;
  height: 100%;
}
.preview-parse.no-parse {
  display: none;
}
.preview-audio-bar {
  display: none;
  flex: 1 1 auto;
  margin-left: 14px;
  padding: 0 0px;
  border-radius: 999px;
  background: rgba(8, 20, 34, 0.82);
  border: 1px solid rgba(255,255,255,0.08);
  height: 30px;
  align-items: center;
}
.preview-audio-bar.has-content {
  display: flex;
}
.preview-audio-bar audio {
  width: 100%;
  height: 100%;
}
body.preview-parse-hidden .preview-column.preview-parse,
body.preview-no-parse .preview-column.preview-parse {
  display: none;
}
body.preview-parse-hidden .preview-resizer,
body.preview-no-parse .preview-resizer {
  display: none;
}
body.preview-parse-hidden .preview-grid,
body.preview-no-parse .preview-grid {
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr);
  grid-template-areas: "main";
}
.preview-panel {
  border-radius: 24px;
  background: var(--surface);
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.18);
  padding: 18px;
  position: relative;
}
.preview-panel-large {
  min-height: 0;
  display: grid;
  gap: 14px;
  grid-template-rows: auto 1fr;
  height: 100%;
}
.preview-main .preview-panel-large {
  grid-template-rows: auto 1fr auto;
}

.preview-main .preview-panel-large,
.preview-column.preview-parse .preview-panel-large {
  min-height: clamp(520px, 72vh, 1180px);
}
.preview-panel-header {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 12px;
  min-height: 36px;
}
.preview-panel-has-action .preview-panel-header {
  padding-right: 112px;
}
.preview-panel-label {
  color: var(--accent-2);
  letter-spacing: 0.12em;
  font-size: 0.82rem;
  text-transform: uppercase;
}
.preview-panel-action {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 4px 12px;
  font-size: 0.82rem;
  font-weight: 600;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(8, 23, 38, 0.8);
  color: var(--text);
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease;
}
.preview-panel-action:hover {
  background: rgba(95,151,255,0.25);
  border-color: rgba(95,151,255,0.5);
}
.preview-panel-action:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
#mainPdf,
#parsePdf {
  width: 100%;
  min-height: 0;
  height: 100%;
  border: none;
  background: #081726;
}
.preview-footer {
  margin-top: 6px;
  padding: 6px 12px;
  border-radius: 12px;
  background: rgba(255,255,255,0.02);
  color: var(--muted);
  text-align: center;
  font-size: 0.82rem;
}

@media (max-width: 768px) {
  .preview-shell {
    padding: 16px;
    gap: 12px;
  }
  .preview-header {
    flex-direction: column;
    align-items: stretch;
  }
  .preview-actions {
    width: 100%;
  }
  .preview-actions .button {
    flex: 1 1 160px;
    justify-content: center;
  }
  .preview-toolbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    width: 100%;
  }
  .preview-shortcuts {
    display: flex;
    overflow-x: auto;
    padding-bottom: 8px;
  }
  .preview-shortcuts {
    max-width: none;
    width: 100%;
    justify-content: flex-start;
  }
  .preview-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
    grid-template-areas:
      "main"
      "parse"
      "utils";
  }
  .preview-resizer {
    display: none;
  }
  .preview-column {
    height: auto;
  }
  .preview-panel {
    padding: 16px;
  }
  .preview-panel-large {
    grid-template-rows: auto minmax(320px, 65vh);
  }
  .preview-main .preview-panel-large {
    grid-template-rows: auto minmax(320px, 65vh) auto;
    min-height: auto;
  }
  .preview-column.preview-parse .preview-panel-large {
    min-height: auto;
  }
  #mainPdf,
  #parsePdf {
    height: 65vh;
  }
}

.footer {
  margin-top: 30px;
  padding: 18px 20px;
  border-radius: 22px;
  background: rgba(255,255,255,0.04);
  color: var(--muted);
  text-align: center;
}
.immersive .site-header,
.immersive .feature-panels,
.immersive .library-section,
.immersive .tips-section,
.immersive .footer,
.immersive #latest,
.immersive #practice {
  display: none;
}
.immersive #viewerSection {
  display: block;
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(7, 20, 33, 0.98);
  padding: 24px;
  overflow: hidden;
}
.immersive .viewer-grid {
  height: calc(100vh - 120px);
}
.immersive .viewer-left,
.immersive .viewer-right {
  min-height: auto;
}
.immersive #pdfViewer {
  min-height: calc(100vh - 220px);
}
.immersive .viewer-left {
  min-height: 100%;
}
.immersive .viewer-right {
  min-height: 100%;
}
@media (max-width: 900px) {
  body {
    padding: 14px;
  }
  .practice-grid,
  .feature-panels,
  .card-grid,
  .tips-grid,
  .viewer-grid {
    grid-template-columns: 1fr;
  }
  .library-grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  }
  .site-header {
    padding: 18px;
  }
  .search-box input {
    width: 100%;
  }
  .viewer-left,
  .viewer-right {
    min-height: auto;
  }
  #pdfViewer {
    min-height: 420px;
  }
}
@media (max-width: 600px) {
  body {
    padding: 10px;
  }
  .site-header {
    padding: 16px;
    border-radius: 20px;
  }
  .site-header h1 {
    font-size: 1.4rem;
  }
  .header-actions {
    flex-direction: column;
  }
  .header-actions .button {
    width: 100%;
    text-align: center;
  }
  .library-section {
    padding: 14px;
    border-radius: 18px;
  }
  .library-header {
    flex-direction: column;
    align-items: stretch;
  }
  .search-box input {
    width: 100%;
  }
  .library-grid {
    grid-template-columns: 1fr;
  }
  .featured-card,
  .library-card,
  .audio-card,
  .panel-card,
  .tip-card {
    padding: 16px;
    border-radius: 16px;
  }
  .library-card .resource-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 10px 12px;
  }
  .resource-item-actions {
    width: 100%;
    justify-content: flex-start;
  }
  .resource-item-actions button {
    padding: 6px 10px;
    font-size: 0.78rem;
  }
  .favorite-button {
    padding: 6px 8px !important;
    font-size: 0.85rem !important;
  }
  .skilltips-nav {
    flex-wrap: wrap;
  }
  .skilltips-accordion .resource-links {
    font-size: 0.88rem;
  }
  .plan-items label {
    font-size: 0.9rem;
  }
}

/* Utility classes */
.empty-state {
  color: var(--muted);
}
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}