:root {
  color-scheme: light;
  font-family: Georgia, "Times New Roman", serif;
  color: #292824;
  background: #f4f1e9;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

body {
  min-width: 280px;
  margin: 0;
  background: #f4f1e9;
}

button {
  font: inherit;
}

.book {
  width: min(100%, 40rem);
  min-height: 100vh;
  margin: 0 auto;
  padding: 1.25rem 1.25rem 2.5rem;
}

.book-header {
  text-align: center;
}

h1 {
  margin: 0;
  font-size: clamp(1.55rem, 5vw, 1.9rem);
  font-weight: 500;
  letter-spacing: 0.08em;
}

.essay-count {
  min-height: 1.5em;
  margin: 0.55rem 0 0.35rem;
  color: #69665d;
  font-family: system-ui, sans-serif;
  font-size: 0.9rem;
  font-variant-numeric: tabular-nums;
}

.tabs {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.15rem;
  color: #aaa59a;
  font-family: system-ui, sans-serif;
}

.tab {
  min-height: 2.75rem;
  padding: 0.55rem 0.5rem;
  border: 0;
  border-bottom: 2px solid transparent;
  color: #69665d;
  background: transparent;
  cursor: pointer;
  font-size: 0.95rem;
}

.tab[aria-selected="true"] {
  border-bottom-color: #292824;
  color: #292824;
  font-weight: 650;
}

.tab:focus-visible,
.nav-button:focus-visible,
.essay-content:focus-visible {
  outline: 2px solid #315f78;
  outline-offset: 3px;
}

.essay-content {
  padding: 1.75rem 0 1.5rem;
  touch-action: pan-y;
}

.essay-content h2 {
  margin: 0 0 2.25rem;
  text-align: center;
  font-size: clamp(1.45rem, 5vw, 1.85rem);
  font-weight: 500;
  line-height: 1.25;
}

.essay-content p {
  margin: 0 0 1.2em;
  font-size: clamp(1.05rem, 2.8vw, 1.16rem);
  line-height: 1.68;
  white-space: pre-line;
}

.vocabulary-list {
  margin: 0;
}

.vocabulary-entry {
  margin-bottom: 1.5rem;
}

.vocabulary-entry dt {
  margin-bottom: 0.25rem;
  font-size: 1.15rem;
  font-weight: 700;
}

.vocabulary-entry dd {
  margin: 0;
  color: #5b5952;
  font-family: system-ui, sans-serif;
  line-height: 1.55;
}

.essay-navigation {
  display: flex;
  justify-content: space-between;
  padding-top: 0.5rem;
}

.nav-button {
  display: grid;
  width: 3rem;
  height: 3rem;
  padding: 0;
  place-items: center;
  border: 1px solid #aaa59a;
  border-radius: 50%;
  color: #292824;
  background: transparent;
  cursor: pointer;
  font-family: system-ui, sans-serif;
  font-size: 2rem;
  line-height: 1;
}

.nav-button:disabled {
  border-color: #d7d3ca;
  color: #b9b5ab;
  cursor: default;
}

.status-message {
  margin: 3rem 0;
  text-align: center;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
}

@media (min-width: 40rem) {
  .book {
    padding: 1.75rem 2rem 3rem;
  }

  .essay-content {
    padding-top: 2rem;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .tab,
  .nav-button {
    transition: color 120ms ease, border-color 120ms ease;
  }
}