/* ISS — Design tokens (DESIGN-GUIDELINES.md) — tema dark */
:root {
  --color-background: #1E1E1E;
  --color-surface: #27272a;
  --color-foreground: #DADADA;
  --color-muted: #a1a1aa;
  --color-border: #3f3f46;
  --color-accent: #5B88B2;
  --color-accent-hover: #82AAE6

  --font-sans: "Inter", ui-sans-serif, system-ui, sans-serif;
  --font-mono: ui-monospace, monospace;

  --text-hero: 1.75rem;
  --text-section: 1.25rem;
  --text-subsection: 1.1rem;
  --text-body: 1rem;
  --text-small: 0.875rem;

  --leading-tight: 1.3;
  --leading-body: 1.6;

  --radius-card: 8px;
  --radius-sm: 4px;

  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.2);

  --max-w-container: 72rem;
  --max-w-read: 65ch;
}

/* Scrollbar padrão do projeto */
html {
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) var(--color-background);
}
*::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
*::-webkit-scrollbar-track {
  background: var(--color-background);
}
*::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}
*::-webkit-scrollbar-thumb:hover {
  background: var(--color-muted);
}

/* Utility classes baseadas nos tokens */
.iss-text-foreground {
  color: var(--color-foreground);
}
.iss-text-muted {
  color: var(--color-muted);
}
.iss-border {
  border-color: var(--color-border);
}
.iss-link {
  color: var(--color-accent);
  text-decoration: none;
}
.iss-link:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}
.iss-link-muted {
  color: var(--color-muted);
  text-decoration: none;
}
.iss-link-muted:hover {
  color: var(--color-accent);
  text-decoration: underline;
}
.iss-search-results-dropdown {
  background: var(--color-surface);
  box-shadow: var(--shadow-card);
}
.iss-search-results-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.iss-search-result-link {
  transition: background 0.5s ease;
}
.iss-search-result-link span.iss-text-foreground {
  transition: color 0.5s ease;
}
.iss-search-result-link:hover {
  background: rgba(63, 63, 70, 0.35);
}
.iss-search-result-link:hover span.iss-text-foreground {
  color: var(--color-accent);
}

/* Base */
body {
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--leading-body);
  color: var(--color-foreground);
  background-color: var(--color-background);
}

/* Typography for article/lesson content */
.iss-prose {
  max-width: var(--max-w-read);
}
.iss-prose h1 {
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: var(--leading-tight);
  margin-bottom: 1rem;
}
.iss-prose h2 {
  font-size: var(--text-section);
  font-weight: 600;
  line-height: var(--leading-tight);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--color-border);
}
.iss-prose h3 {
  font-size: var(--text-subsection);
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}
.iss-prose p {
  margin-bottom: 1rem;
}
.iss-prose ul, .iss-prose ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}
.iss-prose li {
  margin-bottom: 0.25rem;
}
.iss-prose pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1rem;
  overflow-x: auto;
  margin-bottom: 1rem;
}
.iss-prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
}
.iss-prose pre code {
  background: none;
  padding: 0;
}
.iss-prose blockquote {
  margin: 1rem 0;
  padding: 0.75rem 1rem;
  border-left: 4px solid var(--color-border);
  background: rgba(63, 63, 70, 0.2);
  color: var(--color-muted);
  font-style: italic;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* Tabelas no conteúdo das aulas: bordas visíveis */
.iss-prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.iss-prose th,
.iss-prose td {
  border: 1px solid var(--color-border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}
.iss-prose th {
  background: var(--color-surface);
  font-weight: 600;
  color: var(--color-foreground);
}
.iss-prose tbody tr:nth-child(even) {
  background: rgba(63, 63, 70, 0.15);
}

/* Header */
.iss-header {
  height: 56px;
  background: var(--color-background);
  border-bottom: 1px solid var(--color-border);
}

/* Conteúdo ocupa pelo menos a viewport para o footer só aparecer ao rolar */
main,
.iss-page-layout {
  min-height: calc(100vh - 56px);
}

/* Cards (disciplines, lessons) */
.iss-card {
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1rem 1.5rem;
  box-shadow: var(--shadow-card);
  transition: border-color 0.15s, background-color 0.15s;
}
.iss-card:hover {
  background: var(--color-surface);
  border-color: var(--color-muted);
}

/* Superfície para cards (ex.: stats) que precisam de fundo surface */
.iss-surface {
  background: var(--color-surface);
}
.iss-card--static:hover {
  background: var(--color-background);
  border-color: var(--color-border);
}

/* Exercise block */
.iss-exercise {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1rem 1.5rem;
  margin-bottom: 1rem;
  background: var(--color-surface);
  overflow: visible;
}
/* Garantir que a pergunta seja exibida por completo (não cortada) */
.iss-exercise > p.font-medium {
  overflow-wrap: break-word;
  word-wrap: break-word;
  min-width: 0;
}
.iss-exercise__toggle {
  color: var(--color-accent);
  cursor: pointer;
  font-weight: 500;
  border: none;
  background: none;
  padding: 0;
  text-align: left;
}
.iss-exercise__toggle:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

/* details/summary: remove default marker, style like button */
.iss-exercise details summary::-webkit-details-marker {
  display: none;
}
.iss-exercise details[open] summary .inline::after {
  content: " (ocultar)";
  font-weight: normal;
}
.iss-exercise details summary:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}
.iss-exercise--revisado .iss-exercise__revisado-label {
  display: block;
  margin-left: 0;
  margin-top: 0.25rem;
  font-weight: normal;
}

/* Focus visible for links and interactive elements */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Back to top button */
.iss-back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 20;
  padding: 0.5rem 1rem;
  font-size: var(--text-small);
  color: var(--color-accent);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  text-decoration: none;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s;
}
.iss-back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
}
.iss-back-to-top:hover {
  color: var(--color-accent-hover);
  border-color: var(--color-muted);
}

/* Home: grid com linhas explícitas para alinhar cards da mesma linha */
.iss-home-cards__grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
  grid-auto-rows: auto;
}
.iss-home-cards__grid > * {
  min-height: 0;
}
.iss-home-cards__grid .iss-home-cards__exercises-card {
  display: flex;
  flex-direction: column;
}
.iss-home-random-btn {
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.2s ease, background-color 0.2s ease;
}
.iss-home-random-btn:hover {
  opacity: 0.9;
}
@media (min-width: 640px) {
  .iss-home-cards__grid {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: auto auto auto;
  }
  .iss-home-cards__grid > *:nth-child(1) { grid-column: 1; grid-row: 1; }
  .iss-home-cards__grid > *:nth-child(2) { grid-column: 2; grid-row: 1; }
  .iss-home-cards__grid > *:nth-child(3) { grid-column: 1; grid-row: 2; }
  .iss-home-cards__grid > *:nth-child(4) { grid-column: 2; grid-row: 2; }
  .iss-home-cards__grid > *:nth-child(5) { grid-column: 1; grid-row: 3; }
  .iss-home-cards__grid > *:nth-child(6) { grid-column: 2; grid-row: 3; }
  .iss-home-cards__grid > *:nth-child(7) { grid-column: 1 / span 2; grid-row: 4; }
}
@media (min-width: 1024px) {
  .iss-home-cards__grid {
    grid-template-columns: 1fr 1fr 1fr;
    grid-template-rows: auto auto auto;
    gap: 1.25rem;
  }
  .iss-home-cards__grid > *:nth-child(1) { grid-column: 1; grid-row: 1; }
  .iss-home-cards__grid > *:nth-child(2) { grid-column: 2; grid-row: 1; }
  .iss-home-cards__grid > *:nth-child(3) { grid-column: 1; grid-row: 2; }
  .iss-home-cards__grid > *:nth-child(4) { grid-column: 2; grid-row: 2; }
  .iss-home-cards__grid > *:nth-child(5) { grid-column: 1; grid-row: 3; }
  .iss-home-cards__grid > *:nth-child(6) { grid-column: 2; grid-row: 3; }
  .iss-home-cards__grid > *:nth-child(7) { grid-column: 3; grid-row: 1 / -1; }
  .iss-home-cards__grid .iss-home-cards__exercises-card {
    min-height: 0;
    flex: 1;
  }
}

/* Modo foco: esconde header, footer, breadcrumb e back-to-top; só conteúdo */
.iss-focus-exit {
  display: none;
}
body.iss-focus-mode .iss-header,
body.iss-focus-mode footer,
body.iss-focus-mode [id^="breadcrumb-"],
body.iss-focus-mode .iss-back-to-top {
  display: none !important;
}
body.iss-focus-mode .iss-focus-exit {
  display: inline-flex !important;
  align-items: center;
  justify-content: center;
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 30;
  padding: 0.5rem 1rem;
  font-size: var(--text-small);
  color: var(--color-accent);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  cursor: pointer;
  text-decoration: none;
  font-family: var(--font-sans);
  box-shadow: var(--shadow-card);
}
body.iss-focus-mode .iss-focus-exit:hover {
  color: var(--color-accent-hover);
  border-color: var(--color-muted);
}

/* Checklist de domínio (clicável, estado persistido) */
.iss-checklist,
.iss-prose ul.iss-checklist {
  list-style: none;
  padding-left: 0;
}
.iss-checklist-item {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  cursor: pointer;
  margin-bottom: 0.5rem;
  padding: 0.15rem 0;
}
.iss-checklist-item .iss-checklist-box {
  flex-shrink: 0;
  width: 1.1rem;
  height: 1.1rem;
  border: 1.5px solid var(--color-border);
  border-radius: 3px;
  margin-top: 0.2rem;
  cursor: pointer;
  transition: border-color 0.15s, background-color 0.15s;
  position: relative;
}
.iss-checklist-item .iss-checklist-box:hover {
  border-color: var(--color-muted);
}
.iss-checklist-item .iss-checklist-box:focus {
  outline: none;
}
.iss-checklist-item--checked .iss-checklist-box {
  background: var(--color-accent);
  border-color: var(--color-accent);
}
.iss-checklist-item--checked .iss-checklist-box::after {
  content: '';
  position: absolute;
  left: 0.35rem;
  top: 0.15rem;
  width: 0.35rem;
  height: 0.6rem;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}
.iss-checklist-item--checked {
  color: var(--color-muted);
}
.iss-checklist-item--checked .iss-checklist-item__text {
  text-decoration: line-through;
}

/* scroll-margin para headings (compensa o header sticky) */
.iss-prose h2,
.iss-prose h3,
#exercicios {
  scroll-margin-top: 72px;
}

/* Layout de duas colunas na página de aula */
.iss-page-layout {
  display: flex;
  align-items: flex-start;
  justify-content: center;
}

@media (min-width: 1200px) {
  .iss-page-layout {
    display: grid;
    grid-template-columns: 220px 1fr 220px;
    align-items: flex-start;
    justify-content: normal;
  }

  .iss-page-layout > main {
    grid-column: 2;
    grid-row: 1;
  }

  .iss-back-to-top {
    right: calc(220px + 1.5rem);
  }
}

/* Outline sidebar */
.iss-outline {
  display: none;
  width: 220px;
  flex-shrink: 0;
  position: sticky;
  top: 72px;
  max-height: calc(100vh - 72px);
  overflow-y: hidden;
  padding: 1.5rem 0 1.5rem 1.5rem;
  font-size: var(--text-small);
}

/* Mostrar apenas em telas grandes */
@media (min-width: 1200px) {
  .iss-outline:not([hidden]) {
    display: block;
    grid-column: 3;
    grid-row: 1;
  }
}

.iss-outline__title {
  font-size: var(--text-small);
  font-weight: 600;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.iss-outline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.iss-outline__list a {
  display: block;
  padding: 0.2rem 0.5rem;
  color: var(--color-muted);
  text-decoration: none;
  line-height: 1.4;
  border-left: 2px solid transparent;
  transition: color 0.3s ease, border-left-color 0.3s ease;
}

.iss-outline__list a:hover {
  color: var(--color-foreground);
}

.iss-outline__item--h3 > a {
  padding-left: 1.25rem;
  font-size: 0.8125rem;
}

.iss-outline__item--active > a {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

/* No modo foco, esconder o outline */
body.iss-focus-mode .iss-outline {
  display: none !important;
}

/* Botão de copiar código */
.iss-prose pre {
  position: relative;
}

.iss-copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.2rem 0.6rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  line-height: 1.5;
  color: var(--color-muted);
  cursor: pointer;
  opacity: 1;
  transition: color 0.15s, border-color 0.15s;
  z-index: 1;
}

.iss-copy-btn:hover {
  color: var(--color-foreground);
  border-color: var(--color-muted);
}

.iss-copy-btn--copied {
  color: var(--color-accent);
  border-color: var(--color-accent);
  opacity: 1;
}

/* Exercícios práticos: botões de ação e bloco solução */
.iss-exercise-action-btn {
  display: inline-block;
  padding: 0.375rem 0.75rem;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-accent);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, opacity 0.15s;
}
.iss-exercise-action-btn:hover {
  color: var(--color-accent-hover, var(--color-accent));
  border-color: var(--color-muted);
}
.iss-exercise-solution {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}
.iss-exercise-solution.hidden {
  display: none;
}

/* Bloco de código da solução: mesma estética dos blocos em .iss-prose */
#exercise-solution-block pre,
.iss-exercise-solution pre {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1rem 1rem 1.25rem;
  overflow-x: auto;
  margin: 0 0 0.75rem 0;
  position: relative;
  font-size: 0.9rem;
  line-height: 1.5;
}
#exercise-solution-block pre code,
.iss-exercise-solution pre code {
  font-family: var(--font-mono);
  background: none;
  padding: 0;
  display: block;
  white-space: pre;
}
#exercise-solution-block .iss-copy-btn,
.iss-exercise-solution .iss-copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  padding: 0.25rem 0.6rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--color-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}
#exercise-solution-block .iss-copy-btn:hover,
.iss-exercise-solution .iss-copy-btn:hover {
  color: var(--color-foreground);
  border-color: var(--color-muted);
}
#exercise-solution-block .iss-copy-btn--copied,
.iss-exercise-solution .iss-copy-btn--copied {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* Barra de progresso dos exercícios */
.iss-exercise-progress-bar {
  height: 8px;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.iss-exercise-progress-bar__fill {
  height: 100%;
  background: var(--color-accent);
  border-radius: var(--radius-sm);
  transition: width 0.2s ease;
}

/* Tags de conceitos (cards e filtros) */
.iss-tag {
  display: inline-block;
  padding: 0.2rem 0.5rem;
  margin: 0.15rem 0.15rem 0 0;
  font-size: 0.75rem;
  line-height: 1.4;
  color: var(--color-muted);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: default;
}
button.iss-tag {
  cursor: pointer;
  font-family: inherit;
}
button.iss-tag:hover {
  color: var(--color-foreground);
  border-color: var(--color-muted);
}
.iss-tag--active {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: rgba(91, 136, 178, 0.15);
}
.iss-card-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.15rem;
}

/* Indicador "Resolvido" no card */
.iss-exercise-resolved {
  color: var(--color-accent);
  font-weight: 500;
}

/* Confirmação antes de revelar solução */
.iss-solution-confirm {
  padding: 1rem;
  margin-top: 0.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
}
.iss-solution-confirm__buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.75rem;
}
.iss-solution-confirm .iss-exercise-action-btn {
  margin-right: 0;
}