:root {
  --mdr-blue: #149bd7;
  --mdr-ink: #102131;
  --mdr-muted: #5c6b78;
  --mdr-paper: #eef4f8;
  --mdr-panel: #ffffff;
  --mdr-line: #d8e2ea;
  --mdr-dark: #071018;
  --mdr-violet: #6d5fd0;
  --mdr-shadow: 0 12px 32px rgba(15, 33, 49, 0.14);
  --mdr-radius: 8px;
  --mdr-touch: 48px;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html,
body {
  min-width: 320px;
  height: 100%;
  margin: 0;
  overflow: hidden;
  color: var(--mdr-ink);
  background:
    linear-gradient(#dce8f0 1px, transparent 1px),
    linear-gradient(90deg, #dce8f0 1px, transparent 1px),
    var(--mdr-paper);
  background-size: 34px 34px;
  font-family: Arial, Helvetica, sans-serif;
  letter-spacing: 0;
  touch-action: manipulation;
}

button,
select { font: inherit; }

button,
select {
  min-height: var(--mdr-touch);
  border-radius: var(--mdr-radius);
}

button {
  border: 2px solid transparent;
  cursor: pointer;
  font-weight: 900;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

select {
  border: 2px solid var(--mdr-line);
  padding: 0 12px;
  background: #ffffff;
  color: var(--mdr-ink);
  font-weight: 800;
}

button:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 4px solid rgba(20, 155, 215, 0.35);
  outline-offset: 2px;
}

.app {
  height: 100vh;
  height: 100dvh;
  min-height: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  overflow: hidden;
}

.topbar {
  display: grid;
  grid-template-columns: minmax(250px, 1fr) auto;
  align-items: center;
  gap: 12px;
  padding: 6px 14px;
  background: var(--mdr-dark);
  color: #ffffff;
}

.brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-logo {
  display: inline-flex;
  border-radius: 6px;
}

.brand img {
  width: 112px;
  height: auto;
  display: block;
  object-fit: contain;
  flex: 0 0 auto;
}

h1 {
  margin: 0;
  font-size: clamp(1.22rem, 2vw, 2rem);
  line-height: 1.05;
  font-weight: 800;
}

.top-actions {
  display: flex;
  align-items: center;
  justify-content: end;
  gap: 8px;
  flex-wrap: wrap;
}

.icon-button,
.home-button {
  min-height: var(--mdr-touch);
  border: 2px solid #263d51;
  border-radius: var(--mdr-radius);
  background: #122436;
  color: #ffffff;
}

.icon-button {
  width: var(--mdr-touch);
  padding: 0;
  display: inline-grid;
  place-items: center;
}

.home-button {
  padding: 0 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  font-weight: 800;
  white-space: nowrap;
}

.icon-button:hover,
.home-button:hover,
.home-button:focus-visible {
  border-color: #8fd8f3;
  background: var(--mdr-blue);
  color: #06111a;
}

.icon {
  width: 24px;
  height: 24px;
  display: block;
  pointer-events: none;
}

.mdr-root {
  min-height: 0;
  overflow: hidden;
}

.mdr-tool {
  height: 100%;
  min-height: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  overflow: hidden;
}

.mdr-toolbar,
.mdr-control-group,
.mdr-meaning-options {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.mdr-toolbar {
  justify-content: center;
  padding: 8px 14px;
  border-bottom: 1px solid var(--mdr-line);
  background: #ffffff;
  box-shadow: 0 6px 14px rgba(15, 33, 49, 0.06);
  z-index: 3;
}

.mdr-control-label {
  color: var(--mdr-muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.mdr-stepper {
  display: grid;
  grid-template-columns: 42px 58px 42px;
  overflow: hidden;
  border: 2px solid var(--mdr-line);
  border-radius: var(--mdr-radius);
  background: #ffffff;
}

.mdr-stepper button {
  min-height: 44px;
  padding: 0;
  border: 0;
  border-radius: 0;
  background: #f8fbfd;
  color: var(--mdr-ink);
  font-size: 1.25rem;
}

.mdr-stepper button:hover { background: #e7f6fc; }

.mdr-stepper-output {
  min-height: 44px;
  display: grid;
  place-items: center;
  border-inline: 2px solid var(--mdr-line);
  font-size: 1.18rem;
  font-weight: 900;
}

.mdr-wide-button,
.mdr-choice-button {
  min-height: var(--mdr-touch);
  padding: 0 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-color: var(--mdr-line);
  background: #f8fbfd;
  color: var(--mdr-ink);
  white-space: nowrap;
}

.mdr-wide-button.primary,
.mdr-choice-button[aria-pressed="true"] {
  border-color: #4d409f;
  background: var(--mdr-violet);
  color: #ffffff;
}

.mdr-focus-link {
  text-decoration: none;
}

.mdr-meaning-options {
  padding-left: 8px;
  border-left: 1px solid var(--mdr-line);
}

.mdr-workspace {
  min-height: 0;
  overflow: auto;
  overscroll-behavior: contain;
  padding: 8px 12px 12px;
}

.mdr-board {
  width: min(1240px, 100%);
  min-height: 100%;
  margin: 0 auto;
  display: grid;
  grid-template-rows: auto minmax(520px, 1fr);
  gap: 8px;
}

.mdr-equation-strip {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.8fr);
  align-items: center;
  gap: 12px;
  padding: 8px 12px;
  border: 1px solid var(--mdr-line);
  border-radius: var(--mdr-radius);
  background: rgba(255, 255, 255, 0.97);
  box-shadow: var(--mdr-shadow);
}

.mdr-equation,
.mdr-focus-equation {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: clamp(8px, 2vw, 18px);
  font-size: clamp(1.7rem, 3.7vw, 3rem);
  font-weight: 900;
  line-height: 1;
  white-space: nowrap;
}

.mdr-equation-value { min-width: 1.35em; text-align: center; }

.mdr-equation-note {
  color: var(--mdr-muted);
  font-weight: 800;
  line-height: 1.3;
  text-align: right;
}

.mdr-representation-grid {
  min-height: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-template-rows: repeat(2, minmax(250px, 1fr));
  gap: 8px;
}

.mdr-representation-card {
  min-width: 0;
  min-height: 0;
  padding: 7px;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 5px;
  overflow: hidden;
  border: 1px solid var(--mdr-line);
  border-radius: var(--mdr-radius);
  background: rgba(255, 255, 255, 0.97);
  box-shadow: var(--mdr-shadow);
  color: var(--mdr-ink);
  text-align: left;
  transition: border-color 140ms ease, transform 140ms ease;
}

.mdr-representation-card:hover,
.mdr-representation-card:focus-visible {
  border-color: var(--mdr-blue);
}

.mdr-representation-card:active { transform: scale(0.995); }

.mdr-representation-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.mdr-representation-head strong {
  font-size: 0.98rem;
  line-height: 1.1;
}

.mdr-representation-head span {
  color: var(--mdr-muted);
  font-size: 0.75rem;
  font-weight: 800;
  text-align: right;
}

.mdr-model-host,
.mdr-focus-model {
  min-width: 0;
  min-height: 0;
  position: relative;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.mdr-model-host .question-visual,
.mdr-focus-model .question-visual {
  width: 100%;
  height: 100%;
  min-height: 0;
  max-width: 100%;
  max-height: 100%;
  margin: 0;
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
  place-items: center;
  overflow: hidden;
}

.mdr-model-host .question-visual svg,
.mdr-focus-model .question-visual svg {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  min-height: 0;
  display: block;
}

[data-mdr-model-host="array"] .question-visual svg {
  width: auto;
  height: 100%;
  max-height: calc(100% - 33px);
}

.mdr-model-host .question-visual > figcaption,
.mdr-focus-model .question-visual > figcaption {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.mdr-model-host .bar-model-strip span,
.mdr-focus-model .bar-model-strip span {
  min-width: 0;
  padding-inline: 2px;
  font-size: 1.08rem;
}

.mdr-model-host .bar-model,
.mdr-focus-model .bar-model { width: 100%; }

.mdr-model-host .bar-model-strip,
.mdr-focus-model .bar-model-strip { min-height: 64px; }

.mdr-dialog {
  width: min(780px, calc(100vw - 32px));
  max-height: min(820px, calc(100vh - 32px));
  padding: 0;
  overflow: hidden;
  border: 0;
  border-radius: var(--mdr-radius);
  background: #ffffff;
  color: var(--mdr-ink);
  box-shadow: 0 24px 70px rgba(6, 17, 26, 0.32);
}

.mdr-dialog::backdrop { background: rgba(6, 17, 26, 0.58); }

.mdr-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  background: var(--mdr-dark);
  color: #ffffff;
}

.mdr-dialog-header h2 {
  margin: 0;
  font-size: 1.25rem;
  line-height: 1.15;
}

.mdr-dialog-body {
  max-height: calc(min(820px, 100vh - 32px) - 72px);
  overflow: auto;
  padding: 16px 18px 20px;
  line-height: 1.45;
}

.mdr-dialog-body h3 { margin: 16px 0 8px; font-size: 1.05rem; }
.mdr-dialog-body h3:first-child { margin-top: 0; }
.mdr-dialog-body p,
.mdr-dialog-body ul,
.mdr-dialog-body ol { margin: 0 0 10px; }
.mdr-dialog-body li { margin-bottom: 6px; }

.mdr-focus-dialog {
  width: min(1320px, calc(100vw - 28px));
  height: min(880px, calc(100dvh - 28px));
  max-width: none;
}

.mdr-focus-layout {
  height: 100%;
  min-height: 0;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr);
  gap: 10px;
  padding: 12px;
}

.mdr-focus-head {
  display: grid;
  grid-template-columns: minmax(150px, 0.7fr) minmax(220px, 1.4fr) auto;
  align-items: center;
  gap: 12px;
}

.mdr-focus-head h2 {
  margin: 0;
  font-size: clamp(1.15rem, 2.1vw, 1.8rem);
}

.mdr-focus-equation {
  min-height: 54px;
  padding: 6px 12px;
  border: 1px solid var(--mdr-line);
  border-radius: var(--mdr-radius);
  background: #f8fbfd;
}

.mdr-focus-actions {
  display: flex;
  align-items: center;
  justify-content: end;
  gap: 8px;
  flex-wrap: wrap;
}

.mdr-focus-model {
  border: 1px solid var(--mdr-line);
  border-radius: var(--mdr-radius);
  background: #f8fbfd;
}

.mdr-focus-hint {
  min-height: 28px;
  margin: 0;
  color: var(--mdr-muted);
  font-weight: 800;
  text-align: center;
}

.mdr-print-logo,
.mdr-print-copyright { display: none; }

@media (max-width: 980px) {
  html,
  body { overflow: auto; }

  .app {
    height: auto;
    min-height: 100vh;
    overflow: visible;
  }

  .mdr-root,
  .mdr-tool { overflow: visible; }

  .mdr-board { grid-template-rows: auto auto; }

  .mdr-representation-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-template-rows: repeat(3, minmax(250px, 310px));
  }
}

@media (max-width: 700px) {
  .topbar,
  .mdr-equation-strip { grid-template-columns: 1fr; }

  .top-actions { justify-content: start; }

  .mdr-toolbar { justify-content: start; }

  .mdr-equation-note { text-align: center; }

  .mdr-focus-head { grid-template-columns: 1fr; }

  .mdr-focus-head h2 { text-align: center; }

  .mdr-focus-actions { justify-content: center; }
}

@media (max-width: 560px) {
  .mdr-representation-grid {
    grid-template-columns: 1fr;
    grid-template-rows: repeat(6, minmax(250px, 300px));
  }

  .mdr-meaning-options {
    width: 100%;
    padding-left: 0;
    border-left: 0;
  }
}

@media print {
  @page { size: landscape; }

  html,
  body,
  .app,
  .mdr-root,
  .mdr-tool,
  .mdr-workspace,
  .mdr-board {
    height: auto;
    min-height: 0;
    overflow: visible;
    background: #ffffff;
  }

  .topbar,
  .mdr-toolbar,
  .mdr-dialog { display: none !important; }

  .mdr-workspace { padding: 0; }

  .mdr-board { width: 100%; }

  .mdr-equation-strip,
  .mdr-representation-card {
    box-shadow: none;
    break-inside: avoid;
  }

  .mdr-print-logo {
    display: block;
    width: 145px;
    margin: 0 0 8px;
  }

  .mdr-representation-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    grid-template-rows: repeat(2, 250px);
  }

  .mdr-print-copyright {
    display: block;
    margin-top: 8px;
    font-size: 10pt;
    font-weight: 700;
    text-align: right;
  }
}