/* =====================================================
   aboutDegreesAndRadiansStyles.css
   History of Degrees & Radians — reference page
   Shares the same dark-blue theme as unitCircle2.
   ===================================================== */

/* ---------- Root / theme (identical to unitCircle2) ---------- */
:root {
  --uc-bg:        #1a1a2e;
  --uc-panel:     #16213e;
  --uc-card:      #0f3460;
  --uc-accent:    #e94560;
  --uc-accent2:   #f5a623;
  --uc-correct:   #28a745;
  --uc-text:      #e0e0e0;
  --uc-muted:     #8892a4;
  --uc-border:    #2a4a7f;
  --radius:       0.6rem;
}

/* ---------- Global ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background-color: var(--uc-bg);
  color: var(--uc-text);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  min-height: 100vh;
  line-height: 1.65;
}

/* ---------- Navbar ---------- */
.navbar { border-bottom: 2px solid var(--uc-border); }
.navbar-brand span { color: var(--uc-accent2); font-weight: 700; }

.btn-nav-link {
  background: var(--uc-card);
  border: 1px solid var(--uc-border);
  border-radius: var(--radius);
  color: var(--uc-muted);
  font-size: 0.83rem;
  padding: 0.28rem 0.75rem;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s, color 0.2s;
}
.btn-nav-link:hover { background: #1a3a6f; color: var(--uc-text); }

/* ---------- Hero ---------- */
.hero-section {
  background: linear-gradient(180deg, #0f3460 0%, var(--uc-bg) 100%);
  border-bottom: 1px solid var(--uc-border);
}
.hero-title {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--uc-accent2);
  margin-bottom: 0.3rem;
}
.hero-subtitle {
  font-size: 1.05rem;
  color: var(--uc-muted);
  margin-bottom: 1rem;
}
.hero-body {
  font-size: 1rem;
  color: var(--uc-text);
  max-width: 740px;
  margin: 0 auto;
}

/* ---------- Cards / panels ---------- */
.uc-card {
  background: var(--uc-panel);
  border: 1px solid var(--uc-border);
  border-radius: var(--radius);
  padding: 1rem;
}

/* ---------- Section headings ---------- */
.section-heading {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--uc-accent2);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  border-bottom: 1px solid var(--uc-border);
  padding-bottom: 0.45rem;
}
.section-number {
  background: var(--uc-accent);
  color: #fff;
  font-size: 0.88rem;
  font-weight: 700;
  border-radius: 50%;
  width: 1.75rem;
  height: 1.75rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.section-intro {
  color: var(--uc-muted);
  margin-bottom: 1.25rem;
  font-size: 0.97rem;
}

/* ---------- Timeline ---------- */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  position: relative;
  padding-left: 1.2rem;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 0.45rem;
  top: 0.5rem;
  bottom: 0.5rem;
  width: 2px;
  background: linear-gradient(180deg, var(--uc-accent2), var(--uc-accent));
  border-radius: 1px;
}
.timeline-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  padding-left: 0.9rem;
  position: relative;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -0.2rem;
  top: 0.55rem;
  width: 0.65rem;
  height: 0.65rem;
  background: var(--uc-accent2);
  border-radius: 50%;
  border: 2px solid var(--uc-bg);
}
.timeline-date {
  min-width: 7.5rem;
  color: var(--uc-accent2);
  font-size: 0.8rem;
  font-weight: 700;
  padding-top: 0.8rem;
  text-align: right;
  flex-shrink: 0;
}
.timeline-content { flex: 1; }
.timeline-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--uc-text);
  margin-bottom: 0.5rem;
}
.timeline-content p {
  font-size: 0.92rem;
  color: var(--uc-text);
  margin-bottom: 0.5rem;
}
.timeline-content p:last-child { margin-bottom: 0; }

/* ---------- Callout boxes ---------- */
.callout {
  border-radius: var(--radius);
  padding: 0.65rem 0.9rem;
  font-size: 0.88rem;
  margin-top: 0.65rem;
}
.callout-accent2 {
  background: rgba(245, 166, 35, 0.11);
  border-left: 3px solid var(--uc-accent2);
  color: var(--uc-text);
}
.callout-accent {
  background: rgba(233, 69, 96, 0.11);
  border-left: 3px solid var(--uc-accent);
  color: var(--uc-text);
}
.callout-muted {
  background: rgba(136, 146, 164, 0.11);
  border-left: 3px solid var(--uc-muted);
  color: var(--uc-text);
}

/* ---------- Card headings ---------- */
.card-heading {
  font-size: 1rem;
  font-weight: 700;
  color: var(--uc-accent2);
  margin-bottom: 0.6rem;
}

/* ---------- History list ---------- */
.history-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}
.history-list li {
  display: flex;
  gap: 0.7rem;
  font-size: 0.9rem;
  align-items: flex-start;
}
.history-year {
  background: var(--uc-card);
  border: 1px solid var(--uc-border);
  border-radius: 0.35rem;
  color: var(--uc-accent2);
  font-size: 0.76rem;
  font-weight: 700;
  padding: 0.1rem 0.4rem;
  flex-shrink: 0;
  align-self: flex-start;
  margin-top: 0.1rem;
  white-space: nowrap;
}

/* ---------- Formula display box ---------- */
.formula-box {
  background: #0d1b2a;
  border: 1px solid var(--uc-border);
  border-radius: var(--radius);
  padding: 0.6rem 1rem;
  text-align: center;
  margin: 0.5rem 0;
  overflow-x: auto;
}
/* KaTeX display blocks inside formula-box get some breathing room */
.formula-box .katex-display { margin: 0.2rem 0; }

/* ---------- Reason cards (Section 3) ---------- */
.reason-card {
  position: relative;
  padding-top: 1.1rem;
}
.reason-number {
  position: absolute;
  top: -0.65rem;
  left: 1rem;
  background: var(--uc-accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.82rem;
  border-radius: 50%;
  width: 1.45rem;
  height: 1.45rem;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}
.reason-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--uc-accent2);
  margin-bottom: 0.5rem;
  margin-top: 0.15rem;
}
.reason-compare {
  font-size: 0.85rem;
  color: var(--uc-muted);
  margin-top: 0.4rem;
  line-height: 2.1;
}
.label-rad { color: var(--uc-correct); font-weight: 600; }
.label-deg { color: var(--uc-muted); }

/* ---------- Conversion table ---------- */
.conversion-table {
  border-collapse: collapse;
  font-size: 0.9rem;
  width: 100%;
}
.conversion-table th {
  background: var(--uc-card);
  color: var(--uc-accent2);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  padding: 0.6rem 0.8rem;
  text-align: center;
  border-bottom: 2px solid var(--uc-border);
  text-transform: uppercase;
}
.conversion-table td {
  padding: 0.42rem 0.8rem;
  text-align: center;
  border-bottom: 1px solid var(--uc-border);
  color: var(--uc-text);
  font-size: 0.87rem;
}
.conversion-table tr:last-child td { border-bottom: none; }
.conversion-table tbody tr:hover td { background: rgba(42, 74, 127, 0.3); }
.conversion-table .highlight-row td {
  background: rgba(245, 166, 35, 0.09);
  color: var(--uc-accent2);
  font-weight: 600;
}

/* ---------- CTA section ---------- */
.cta-card { border-color: var(--uc-accent2); }
.cta-text {
  font-size: 1.1rem;
  color: var(--uc-text);
  margin-bottom: 0.85rem;
}
.btn-cta {
  background: var(--uc-accent2);
  border: none;
  border-radius: var(--radius);
  color: #0f3460;
  font-weight: 700;
  font-size: 1rem;
  padding: 0.55rem 2.2rem;
  text-decoration: none;
  display: inline-block;
  transition: background 0.2s, transform 0.1s;
}
.btn-cta:hover { background: #e09820; color: #0f3460; transform: scale(1.03); }

/* ---------- Responsive tweaks ---------- */
@media (max-width: 768px) {
  .hero-title { font-size: 1.75rem; }
  .timeline { padding-left: 0.8rem; }
  .timeline-date { min-width: 5.5rem; font-size: 0.75rem; }
  .timeline-item { gap: 0.6rem; }
}