:root {
  --color-bg: #f6f3ee;
  --color-surface: #ffffff;
  --color-surface-2: #faf7f2;
  --color-text: #23201b;
  --color-muted: #6b6355;
  --color-border: #e4ddd0;
  --color-accent: #8a1f11;
  --color-accent-strong: #6e190d;
  --color-accent-contrast: #ffffff;
  --color-success-bg: #e6f4ea;
  --color-success-text: #1e6b34;
  --color-error-bg: #fbe7e6;
  --color-error-text: #8a1f11;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 2px rgba(30, 24, 14, 0.06);
  --shadow-md: 0 6px 20px rgba(30, 24, 14, 0.08);
  --font-display: Charter, "Iowan Old Style", "Georgia", "Times New Roman", serif;
  --font-body: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #17150f;
    --color-surface: #221f19;
    --color-surface-2: #2a261f;
    --color-text: #eee8dc;
    --color-muted: #a89b85;
    --color-border: #3a352b;
    --color-accent: #e08a6f;
    --color-accent-strong: #f0a488;
    --color-accent-contrast: #17150f;
    --color-success-bg: #163821;
    --color-success-text: #7fd79a;
    --color-error-bg: #3a1c19;
    --color-error-text: #f2a79c;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 10px 28px rgba(0, 0, 0, 0.4);
  }
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

a { color: var(--color-accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--color-accent-strong); }

::selection { background: var(--color-accent); color: var(--color-accent-contrast); }

/* --- Header --- */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(1.1);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
}
.site-header .brand {
  font-family: var(--font-display);
  font-weight: 700;
  text-decoration: none;
  color: var(--color-text);
  font-size: 1.15rem;
  letter-spacing: 0.01em;
}
.site-header nav a, .site-header nav .link-button {
  margin-left: 1rem;
  text-decoration: none;
  font-size: 0.9rem;
  color: var(--color-muted);
}
.site-header nav a:hover, .site-header nav .link-button:hover { color: var(--color-accent); }

main { padding: 2.5rem 1.25rem 5rem; }

/* --- Typography --- */
h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.25;
}
h1 { font-size: 1.9rem; margin: 0 0 1.1rem; }
h2 { font-size: 1.4rem; margin: 1.6rem 0 0.8rem; }
h3 { font-size: 1.1rem; margin: 1.2rem 0 0.6rem; color: var(--color-muted); }

.case-badge {
  display: inline-block;
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border-radius: 999px;
  padding: 0.15em 0.75em;
  font-family: var(--font-body);
  font-size: 0.6em;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  vertical-align: middle;
  margin-right: 0.5em;
}

.rich-text { font-size: 1.02rem; }
.rich-text p { margin: 0 0 1em; }
.rich-text img { max-width: 100%; height: auto; border-radius: var(--radius-sm); box-shadow: var(--shadow-sm); }
.rich-text iframe { max-width: 100%; border-radius: var(--radius-sm); border: none; }
/* A paragraph consisting only of a <i> run is a legacy image caption pattern
   (<p><i>...</i></p>); style it as a caption. <em> is never touched here —
   it's used for normal inline emphasis mid-sentence throughout the content. */
.rich-text p > i:only-child {
  display: block;
  color: var(--color-muted);
  font-size: 0.88em;
  margin-top: -0.6em;
}
.rich-text table { border-collapse: collapse; max-width: 100%; margin-bottom: 1em; }
.rich-text table td, .rich-text table th { border: 1px solid var(--color-border); padding: 0.5em 0.7em; }
.rich-text ul, .rich-text ol { padding-left: 1.4em; }
.rich-text li { margin-bottom: 0.35em; }

/* --- Homepage --- */
.intro { margin-bottom: 1rem; }

.case-grid { margin-top: 2.5rem; }
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 0.9rem;
  margin-top: 1rem;
}
.card {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.card:hover { border-color: var(--color-accent); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.card-number {
  display: inline-flex;
  flex: none;
  align-items: center;
  justify-content: center;
  width: 1.9em;
  height: 1.9em;
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border-radius: 50%;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95em;
}
.card-title { font-weight: 600; }
.card-muted { opacity: 0.85; }
.teacher-info { margin-top: 1.5rem; }

/* --- Case page --- */
.topic { margin-top: 2.75rem; padding-top: 1.75rem; border-top: 1px solid var(--color-border); }
.topic:first-of-type { border-top: none; padding-top: 0; }

.topic-files, .topic-quizzes { margin-top: 1.2rem; }
.quiz-button {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  background: var(--color-surface);
  border: 1px solid var(--color-accent);
  color: var(--color-accent);
  border-radius: var(--radius-sm);
  padding: 0.65rem 1.1rem;
  text-decoration: none;
  font-weight: 600;
  margin: 0.25rem 0.4rem 0.25rem 0;
  transition: background 0.15s ease, color 0.15s ease;
}
.quiz-button:hover { background: var(--color-accent); color: var(--color-accent-contrast); }

.back-link { margin-bottom: 0.5rem; }
.back-link a { text-decoration: none; color: var(--color-muted); font-size: 0.9rem; }
.back-link a:hover { color: var(--color-accent); }

/* --- Quiz flow --- */
.quiz-progress { color: var(--color-muted); margin-bottom: 1.2rem; font-size: 0.9rem; letter-spacing: 0.02em; }
.quiz-prompt { font-family: var(--font-display); font-size: 1.25rem; line-height: 1.45; }
.quiz-image { max-width: 100%; border-radius: var(--radius); box-shadow: var(--shadow-sm); margin-bottom: 1rem; }
.choice {
  display: flex;
  align-items: center;
  gap: 0.7em;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.8rem 1.1rem;
  margin-bottom: 0.55rem;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}
.choice:hover { border-color: var(--color-accent); background: var(--color-surface-2); }
.choice input { accent-color: var(--color-accent); width: 1.1em; height: 1.1em; flex: none; }

.btn {
  display: inline-block;
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-sm);
  padding: 0.7rem 1.4rem;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}
.btn:hover { background: var(--color-accent-strong); border-color: var(--color-accent-strong); }
.btn:active { transform: translateY(1px); }
.btn-secondary { background: transparent; color: var(--color-accent); }
.btn-secondary:hover { background: var(--color-accent); color: var(--color-accent-contrast); }
.btn-small { padding: 0.35rem 0.75rem; font-size: 0.85rem; }
.btn-danger { background: var(--color-error-text); border-color: var(--color-error-text); }
.btn-danger:hover { filter: brightness(0.9); }

.quiz-feedback { border-radius: var(--radius); padding: 1.1rem 1.2rem; margin: 1.2rem 0; }
.feedback-correct { background: var(--color-success-bg); color: var(--color-success-text); }
.feedback-wrong { background: var(--color-error-bg); color: var(--color-error-text); }
.feedback-headline { font-weight: 700; margin: 0 0 0.4em; font-size: 1.05em; }

.quiz-result { font-size: 1.2rem; }

.flash { border-radius: var(--radius-sm); padding: 0.85rem 1.1rem; margin-bottom: 1.5rem; font-size: 0.95rem; }
.flash-success { background: var(--color-success-bg); color: var(--color-success-text); }
.flash-error { background: var(--color-error-bg); color: var(--color-error-text); }

.site-footer { border-top: 1px solid var(--color-border); color: var(--color-muted); font-size: 0.85rem; margin-top: 3rem; }
.site-footer .wrap { padding: 1.5rem 1.25rem; }

.link-button { background: none; border: none; padding: 0; font: inherit; color: var(--color-muted); cursor: pointer; text-decoration: underline; }
.link-button:hover { color: var(--color-accent); }
.inline { display: inline; }

/* --- Admin --- */
.admin-table { width: 100%; border-collapse: collapse; margin: 1rem 0 2rem; }
.admin-table th, .admin-table td { text-align: left; padding: 0.6rem 0.7rem; border-bottom: 1px solid var(--color-border); vertical-align: middle; }
.admin-table th { color: var(--color-muted); font-weight: 600; font-size: 0.82rem; text-transform: uppercase; letter-spacing: 0.03em; }
.admin-table tr:hover td { background: var(--color-surface-2); }
.admin-actions { white-space: nowrap; }
.admin-actions form { display: inline; }
.admin-actions a, .admin-actions button { margin-right: 0.4rem; font-size: 0.85rem; }

.form-field { margin-bottom: 1.2rem; }
.form-field label { display: block; font-weight: 600; margin-bottom: 0.35rem; font-size: 0.95rem; }
.form-field input[type=text], .form-field input[type=number], .form-field input[type=password],
.form-field input[type=url], .form-field input[type=file], .form-field textarea, .form-field select {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font: inherit;
  background: var(--color-surface);
  color: var(--color-text);
  transition: border-color 0.15s ease;
}
.form-field input:focus, .form-field textarea:focus, .form-field select:focus {
  outline: none;
  border-color: var(--color-accent);
}
.form-field .hint { color: var(--color-muted); font-size: 0.85rem; margin-top: 0.3rem; }
.form-check { display: flex; align-items: center; gap: 0.5em; margin-bottom: 0.9rem; }
.form-check input { accent-color: var(--color-accent); }
.form-check label { font-weight: 400; margin: 0; }

.admin-section { margin-top: 2.75rem; padding-top: 1.75rem; border-top: 1px solid var(--color-border); }
.admin-section h2 { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }

.choice-row { display: flex; align-items: center; gap: 0.6rem; margin-bottom: 0.5rem; }
.choice-row input[type=checkbox] { accent-color: var(--color-accent); }
.choice-row input[type=text] { flex: 1; }

.login-box {
  max-width: 380px;
  margin: 3.5rem auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow-md);
}
.login-box h1 { font-size: 1.4rem; margin-bottom: 1.3rem; }