/* ============================================================
   ORBIT COURSE - course.css
   21-Day Astronomy Course | RiSa Astronomy
   Extends shared.css (loaded from /assets/css/shared.css)
   ============================================================ */

/* --- Malayalam Font (not in shared.css) --- */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+Malayalam:wght@400;600;700&display=swap');

/* --- Course-Specific Tokens --- */
:root {
  --course-green: #3fb950;
  --course-green-bg: rgba(63, 185, 80, 0.08);
  --course-gold-bg: rgba(212, 160, 23, 0.08);
  --course-blue-bg: rgba(30, 91, 184, 0.08);
  --font-ml: 'Noto Sans Malayalam', sans-serif;
  --lesson-max-width: 720px;
  --embed-height-desktop: 600px;
  --embed-height-mobile: 70vh;
}

/* ============================================================
   LANGUAGE TOGGLE
   ============================================================ */
.ml-text { display: none; }
.ml-inline { display: none; }
.en-inline { display: inline; }

body.ml { font-family: var(--font-ml); line-height: 1.85; }
body.ml .en-text { display: none; }
body.ml .ml-text { display: block; }
body.ml .en-inline { display: none; }
body.ml .ml-inline { display: inline; }

/* ============================================================
   COURSE BAR (sub-header below main nav)
   ============================================================ */
.course-bar {
  position: fixed;
  top: calc(var(--header-height) + var(--nav-height));
  left: 0;
  right: 0;
  height: 40px;
  background: rgba(17, 24, 39, 0.95);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-subtle);
  z-index: calc(var(--z-header) - 2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-4);
  max-width: 100%;
}

.course-bar__brand {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-blue-300);
  text-decoration: none;
  letter-spacing: 0.5px;
}

.course-bar__brand:hover {
  color: var(--color-blue-200);
  text-decoration: none;
}

.course-bar__day {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--text-tertiary);
}

.course-bar__controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.course-bar__lang-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 32px;
  padding: 0 var(--space-3);
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.course-bar__lang-btn:hover {
  border-color: var(--border-default);
  color: var(--text-primary);
}

/* Adjust orbit-main margin to account for course-bar */
.course-page .orbit-main {
  margin-top: calc(var(--header-height) + var(--nav-height) + 40px);
}

/* ============================================================
   BUTTONS (course-specific)
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  height: 34px;
  padding: 0 var(--space-3);
  background: var(--bg-surface-raised);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.btn:hover {
  background: var(--bg-surface-hover);
  border-color: var(--border-default);
  color: var(--text-primary);
  text-decoration: none;
}

.btn--complete {
  background: rgba(63, 185, 80, 0.12);
  border-color: var(--course-green);
  color: var(--course-green);
}

.btn--complete:hover {
  background: rgba(63, 185, 80, 0.2);
}

.btn--completed {
  background: rgba(63, 185, 80, 0.15);
  border-color: var(--course-green);
  color: var(--course-green);
  cursor: default;
  opacity: 0.8;
}

/* ============================================================
   LESSON CONTAINER
   ============================================================ */
.lesson-container {
  max-width: var(--lesson-max-width);
  margin: 0 auto;
  padding: var(--space-8) var(--space-4) var(--space-16);
}

.week-banner {
  margin-bottom: var(--space-8);
  padding: var(--space-4) 0;
  border-top: 2px solid var(--color-gold-500);
}

.week-banner h2 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-gold-400);
  margin-bottom: var(--space-1);
}

.week-banner p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  font-style: italic;
}

.lesson-day-label {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-blue-300);
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.lesson-container h1 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: var(--space-6);
  line-height: var(--leading-tight);
}

.lesson-container h4 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-gold-400);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.lesson-container p { margin-bottom: var(--space-4); }
.lesson-container ul, .lesson-container ol { margin: var(--space-3) 0 var(--space-4) var(--space-5); }
.lesson-container li { margin-bottom: var(--space-2); }
.lesson-container strong { color: var(--text-heading); }
.lesson-container em { color: var(--color-blue-200); font-style: italic; }

/* ============================================================
   CALLOUT BOXES
   ============================================================ */
.callout {
  padding: var(--space-3) var(--space-4);
  margin: var(--space-4) 0;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

.callout strong { display: block; margin-bottom: var(--space-1); }
.callout--exercise { background: var(--course-green-bg); border-left: 3px solid var(--course-green); }
.callout--exercise strong { color: var(--course-green); }
.callout--takeaway { background: var(--course-gold-bg); border-left: 3px solid var(--color-gold-500); }
.callout--takeaway strong { color: var(--color-gold-400); }

/* ============================================================
   ORBIT EMBED COMPONENT
   ============================================================ */
.orbit-embed {
  margin: var(--space-5) 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-default);
  transition: border-color var(--transition-base);
}

.orbit-embed:hover { border-color: var(--color-blue-500); }

.orbit-embed__trigger {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-4);
  background: var(--bg-surface);
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  font-size: var(--text-base);
  transition: background var(--transition-fast);
}

.orbit-embed__trigger:hover { background: var(--bg-surface-raised); }

.orbit-embed__icon {
  font-size: var(--text-xl);
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--course-blue-bg);
  border-radius: var(--radius-md);
}

.orbit-embed__info { flex: 1; min-width: 0; }
.orbit-embed__info strong { display: block; color: var(--color-blue-300); font-size: var(--text-sm); font-weight: 600; }
.orbit-embed__hint { display: block; font-size: var(--text-xs); color: var(--text-tertiary); margin-top: 2px; }
.orbit-embed__arrow { flex-shrink: 0; font-size: var(--text-sm); color: var(--text-tertiary); transition: transform var(--transition-base); }
.orbit-embed[data-expanded="true"] .orbit-embed__arrow { transform: rotate(180deg); }

.orbit-embed__panel { overflow: hidden; max-height: 0; transition: max-height 0.4s ease; }
.orbit-embed[data-expanded="true"] .orbit-embed__panel { max-height: calc(var(--embed-height-desktop) + 60px); }
.orbit-embed__iframe-wrap { position: relative; height: var(--embed-height-desktop); background: var(--bg-space); }
.orbit-embed__iframe-wrap iframe { width: 100%; height: 100%; border: none; }

.orbit-embed__loader { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; flex-direction: column; gap: var(--space-3); color: var(--text-tertiary); font-size: var(--text-sm); }
.orbit-embed__loader .spinner { width: 32px; height: 32px; border: 3px solid var(--border-default); border-top-color: var(--color-blue-400); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.orbit-embed__loader.loaded { display: none; }

.orbit-embed__footer { display: flex; align-items: center; justify-content: space-between; padding: var(--space-2) var(--space-4); background: var(--bg-surface); border-top: 1px solid var(--border-subtle); font-size: var(--text-xs); }
.orbit-embed__fullscreen { color: var(--text-link); font-size: var(--text-xs); }
.orbit-embed__collapse { background: none; border: none; color: var(--text-tertiary); cursor: pointer; font-size: var(--text-xs); font-family: inherit; padding: var(--space-1) var(--space-2); }
.orbit-embed__collapse:hover { color: var(--text-primary); }

/* ============================================================
   ILLUSTRATIONS
   ============================================================ */
.illustration { margin: var(--space-6) 0; text-align: center; }
.illustration svg { max-width: 100%; height: auto; }
.illustration figcaption { margin-top: var(--space-2); font-size: var(--text-xs); color: var(--text-tertiary); font-style: italic; }

/* ============================================================
   LESSON NAVIGATION
   ============================================================ */
.lesson-nav {
  max-width: var(--lesson-max-width);
  margin: 0 auto;
  padding: var(--space-6) var(--space-4) var(--space-12);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-subtle);
}

.lesson-nav__prev, .lesson-nav__next {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.lesson-nav__prev:hover, .lesson-nav__next:hover {
  background: var(--bg-surface-raised);
  border-color: var(--border-default);
  color: var(--text-primary);
  text-decoration: none;
}

.lesson-nav__center { display: flex; gap: var(--space-2); align-items: center; }

/* ============================================================
   COURSE OVERVIEW PAGE
   ============================================================ */
.overview-container { max-width: var(--container-lg); margin: 0 auto; padding: var(--space-4); }

.course-hero { text-align: center; padding: var(--space-12) 0 var(--space-8); border-bottom: 1px solid var(--border-subtle); margin-bottom: var(--space-8); }
.course-hero h1 { font-family: var(--font-display); font-size: var(--text-4xl); font-weight: 700; color: var(--text-heading); margin-bottom: var(--space-2); }
.course-hero .subtitle { font-size: var(--text-lg); color: var(--text-secondary); margin-bottom: var(--space-4); }
.course-hero .tagline { font-size: var(--text-sm); color: var(--text-tertiary); font-style: italic; max-width: 520px; margin: 0 auto; line-height: var(--leading-relaxed); }

.progress-bar { max-width: 400px; margin: var(--space-6) auto var(--space-2); }
.progress-bar__track { height: 6px; background: var(--bg-surface); border-radius: var(--radius-full); overflow: hidden; }
.progress-bar__fill { height: 100%; background: var(--course-green); border-radius: var(--radius-full); transition: width 0.4s ease; width: 0%; }
.progress-bar__label { text-align: center; font-size: var(--text-xs); color: var(--text-tertiary); margin-top: var(--space-2); }

.intro-box { background: var(--bg-surface); border: 1px solid var(--border-subtle); border-radius: var(--radius-md); padding: var(--space-4); margin-bottom: var(--space-8); font-size: var(--text-sm); color: var(--text-secondary); line-height: var(--leading-relaxed); max-width: var(--lesson-max-width); margin-left: auto; margin-right: auto; }
.intro-box strong { color: var(--text-primary); }

.week-section { margin-bottom: var(--space-10); }
.week-section__header { padding: var(--space-3) 0; border-top: 2px solid var(--color-gold-500); margin-bottom: var(--space-4); }
.week-section__header h2 { font-family: var(--font-display); font-size: var(--text-xl); font-weight: 700; color: var(--color-gold-400); margin-bottom: var(--space-1); }
.week-section__header p { font-size: var(--text-sm); color: var(--text-secondary); font-style: italic; }

.day-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: var(--space-4); }

.day-card { display: flex; align-items: flex-start; gap: var(--space-3); padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border-subtle); border-radius: var(--radius-md); text-decoration: none; color: var(--text-primary); transition: all var(--transition-fast); }
.day-card:hover { background: var(--bg-surface-raised); border-color: var(--border-default); box-shadow: var(--shadow-sm); text-decoration: none; }
.day-card__number { flex-shrink: 0; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; border-radius: var(--radius-full); background: var(--bg-surface-raised); border: 1px solid var(--border-default); font-family: var(--font-display); font-size: var(--text-sm); font-weight: 700; color: var(--text-secondary); }
.day-card--completed .day-card__number { background: rgba(63, 185, 80, 0.15); border-color: var(--course-green); color: var(--course-green); }
.day-card__content h3 { font-family: var(--font-display); font-size: var(--text-sm); font-weight: 600; color: var(--text-heading); margin-bottom: 2px; }
.day-card__content p { font-size: var(--text-xs); color: var(--text-tertiary); line-height: 1.4; }

.bonus-section { margin-top: var(--space-10); padding-top: var(--space-6); border-top: 2px solid var(--color-blue-500); }
.bonus-section h2 { font-family: var(--font-display); font-size: var(--text-xl); font-weight: 700; color: var(--color-blue-300); margin-bottom: var(--space-4); }

/* ============================================================
   TABLES
   ============================================================ */
.lesson-container table { width: 100%; border-collapse: collapse; margin: var(--space-4) 0; font-size: var(--text-sm); }
.lesson-container th { background: var(--bg-surface); color: var(--color-gold-400); text-align: left; padding: var(--space-2) var(--space-3); border: 1px solid var(--border-default); font-weight: 600; }
.lesson-container td { padding: var(--space-2) var(--space-3); border: 1px solid var(--border-default); }
.lesson-container tr:nth-child(even) td { background: var(--bg-surface); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .course-hero h1 { font-size: var(--text-2xl); }
  .lesson-container h1 { font-size: var(--text-2xl); }
  .day-grid { grid-template-columns: 1fr; }
  .orbit-embed__iframe-wrap { height: var(--embed-height-mobile); }
  .orbit-embed[data-expanded="true"] .orbit-embed__panel { max-height: calc(var(--embed-height-mobile) + 60px); }
  .lesson-nav { flex-direction: column; align-items: stretch; }
  .lesson-nav__prev, .lesson-nav__next { justify-content: center; }
  .lesson-nav__center { justify-content: center; }
}

@media (max-width: 480px) {
  .lesson-container { padding: var(--space-6) var(--space-3) var(--space-12); }
  .course-bar__day { display: none; }
}