/* Language learning site - shared stylesheet */

:root {
  --bg: #f6f4ef;
  --surface: #ffffff;
  --text: #22252b;
  --muted: #5d6470;
  --accent: #b3261e;
  --accent-dark: #8c1d17;
  --nav-highlight: #ffd54a;
  --line: #e2ded5;
  --ok: #1e7b3a;
  --ok-bg: #e5f4e9;
  --bad: #b3261e;
  --bad-bg: #fbe9e7;
  --radius: 10px;
  --max: 60rem;
}

:root[data-theme="blue"] {
  --accent: #0039a6;
  --accent-dark: #002a7a;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 1.0625rem/1.65 "Segoe UI", "Noto Sans", "PT Sans", Roboto,
    "Helvetica Neue", Arial, sans-serif;
}

a { color: var(--accent); }
a:hover { color: var(--accent-dark); }

/* --- header ------------------------------------------------------------- */

.site-header { background: var(--surface); }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  max-width: var(--max);
  margin: 0 auto;
  padding: .6rem 1rem;
}

.brand {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--text);
  line-height: 1.25;
}
.brand-title { font-size: 1.35rem; font-weight: 700; }
.brand-subtitle { font-size: .85rem; color: var(--muted); }

.lang-switch { display: flex; gap: .5rem; flex-shrink: 0; }
.flag {
  display: block;
  line-height: 0;
  border-radius: 4px;
  outline: 2px solid transparent;
  opacity: .55;
  transition: opacity .15s;
}
.flag:hover, .flag:focus-visible { opacity: 1; }
.flag[aria-current] { opacity: 1; outline-color: var(--line); }
.flag img { display: block; border-radius: 3px; }

/* banner: the whole image, no cropping or aspect ratio change */
.banner {
  max-width: var(--max);
  margin: 0 auto;
  line-height: 0;
}
.banner img { display: block; width: 100%; height: auto; }

.main-nav {
  max-width: var(--max);
  margin: 0 auto;
  background: var(--accent);
  position: sticky;
  top: 0;
  z-index: 10;
}
.main-nav ul {
  display: flex;
  flex-wrap: wrap;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 .5rem;
  list-style: none;
}
.main-nav a {
  display: block;
  padding: .7rem .9rem;
  color: #fff;
  text-decoration: none;
  font-weight: 600;
}
.main-nav a.highlight { color: var(--nav-highlight); }
.main-nav a:hover { background: var(--accent-dark); }
.main-nav a[aria-current] {
  background: var(--accent-dark);
  box-shadow: inset 0 -3px 0 #fff;
}

/* --- content ------------------------------------------------------------ */

.content {
  max-width: var(--max);
  margin: 1.5rem auto;
  padding: 1.5rem 2rem 2rem;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgba(0, 0, 0, .06);
}

h1, h2, h3 { line-height: 1.3; }
h1 { font-size: 1.7rem; margin: .3rem 0 1rem; }
h2 { font-size: 1.35rem; margin: 1.8rem 0 .6rem; }
h3 { font-size: 1.15rem; }

.lead { color: var(--muted); }
.indent { padding-left: 2rem; }

.intro h3 { font-weight: 500; }

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1rem;
}
.card {
  display: flex;
  flex-direction: column;
  gap: .4rem;
  padding: 1.2rem;
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  border-radius: var(--radius);
  color: var(--text);
  text-decoration: none;
  transition: box-shadow .15s, transform .15s;
}
.card:hover {
  color: var(--text);
  box-shadow: 0 4px 14px rgba(0, 0, 0, .1);
  transform: translateY(-2px);
}
.card-title { font-size: 1.25rem; font-weight: 700; color: var(--accent); }
.card-desc { color: var(--muted); }
.card-count { font-size: .85rem; color: var(--muted); margin-top: auto; }

.article-list { padding-left: 1.6rem; }
.article-list li { padding: .3rem 0; border-bottom: 1px solid var(--line); }
.article-list a { text-decoration: none; }
.article-list a:hover { text-decoration: underline; }

.back { margin: 0 0 .5rem; font-size: .95rem; }
.back a { text-decoration: none; }
.article .back:last-child { margin-top: 2rem; }

/* --- audio -------------------------------------------------------------- */

.audio {
  display: flex;
  align-items: center;
  gap: .6rem;
  margin: 1.2rem 0;
  padding: .6rem .8rem;
  background: var(--bg);
  border-radius: var(--radius);
}
.audio audio { display: block; flex: 1 1 auto; min-width: 0; }
.audio-download {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 50%;
  color: var(--muted);
}
.audio-download:hover, .audio-download:focus-visible {
  color: var(--accent);
  background: var(--surface);
}

/* --- expandable dictation text ------------------------------------------ */

.slide {
  margin: 1rem 0 1.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.slide summary {
  padding: .7rem 1rem;
  cursor: pointer;
  font-weight: 600;
  color: var(--accent);
}
.slide[open] summary { border-bottom: 1px solid var(--line); }
.slide-body { padding: 0 1rem; }

/* --- exercises ---------------------------------------------------------- */

.exercise {
  margin: 1.2rem 0;
  padding: 1rem 1.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.exercise-body { line-height: 2.1; }
.exercise-body p { margin: 0 0 .6rem; }
.hint { color: var(--muted); }
.blank { white-space: nowrap; }
.blank-field {
  font: inherit;
  padding: .1rem .4rem;
  border: 1px solid #b9b3a7;
  border-radius: 6px;
  background: #fffdf8;
  max-width: 100%;
}
.blank-field:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.blank-field.is-ok {
  border-color: var(--ok);
  background: var(--ok-bg);
}
.blank-field.is-bad {
  border-color: var(--bad);
  background: var(--bad-bg);
}
.blank-answer {
  margin-left: .3rem;
  color: var(--ok);
  font-weight: 600;
}

.exercise-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
  margin-top: 1rem;
}
.btn {
  font: inherit;
  padding: .45rem 1rem;
  border: 1px solid var(--accent);
  border-radius: 6px;
  background: #fff;
  color: var(--accent);
  cursor: pointer;
}
.btn:hover { background: var(--bad-bg); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.exercise-result { font-weight: 600; }

/* --- footer ------------------------------------------------------------- */

.site-footer {
  padding: 1rem;
  text-align: center;
  color: var(--muted);
  font-size: .9rem;
}

/* --- mobile devices ----------------------------------------------------- */

@media (max-width: 40rem) {
  body { font-size: 1rem; }
  .brand-title { font-size: 1.15rem; }
  .brand-subtitle { display: none; }
  .main-nav ul { padding: 0; }
  .main-nav li { flex: 1 1 50%; }
  .main-nav a { padding: .6rem .7rem; text-align: center; }
  .content {
    margin: 0;
    padding: 1rem;
    border-radius: 0;
    box-shadow: none;
  }
  h1 { font-size: 1.4rem; }
  .indent { padding-left: 1rem; }
  .exercise { padding: .8rem; }
}

/* --- tables ------------------------------------------------------------- */

.table-wrap { overflow-x: auto; margin: 1rem 0; }
table { border-collapse: collapse; }
td, th { padding: .35rem .9rem; border: 1px solid var(--line); }
tr:nth-child(odd) td { background: var(--bg); }
td:first-child { font-weight: 600; }