/* ============================================================
   BOTR AC TRAINING — STYLESHEET
   Design system: Course Management Platform palette
   ============================================================ */

:root {
  --accent:          #0078d4;
  --accent-dark:     #106ebe;
  --accent-subtle:   rgba(0,120,212,0.08);
  --title-top:       #EAF4FF;
  --title-bottom:    #D8E9FF;
  --title-border:    #AFC8E8;
  --surface:         #F8F8F8;
  --white:           #FFFFFF;
  --border:          #C0C0C0;
  --border-soft:     #E0E0E0;
  --text-primary:    #333333;
  --text-secondary:  #555555;
  --text-muted:      #888888;
  --green:           #2E7D32;
  --green-light:     #4CAF50;
  --yellow:          #F9A825;
  --red:             #E53935;
  --red-dark:        #C62828;
  --danger-bg:       #ffe6e6;
  --danger-border:   #ffcccc;
  --danger-text:     #cc0000;
}

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

body {
  font-family: 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--white);
  min-height: 100vh;
}

/* --- TOP HEADER --- */
.site-header {
  background: linear-gradient(to bottom, var(--title-top), var(--title-bottom));
  border-bottom: 2px solid var(--title-border);
  padding: 0 32px;
  display: flex;
  align-items: center;
  gap: 20px;
  height: 60px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header .logo {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  text-decoration: none;
}

.site-header .logo:hover { color: var(--accent-dark); }

.site-header .logo span { color: var(--text-secondary); }

.breadcrumb {
  color: var(--text-muted);
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb b { color: var(--text-secondary); }

.home-link {
  margin-left: auto;
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
}

.home-link:hover { color: var(--accent-dark); }

.header-badge {
  margin-left: 16px;
  background: var(--accent);
  color: white;
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 3px;
}

/* --- LAYOUT --- */
.layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - 60px);
}

/* --- SIDEBAR --- */
.sidebar {
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 16px 0;
  position: sticky;
  top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
}

.sidebar-section-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: 12px 16px 4px;
  margin-top: 8px;
}

.sidebar a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s;
  border-left: 3px solid transparent;
}

.sidebar a:hover, .sidebar a.active {
  background: var(--title-top);
  color: var(--accent);
  border-left-color: var(--accent);
}

.sidebar a .icon {
  font-size: 15px;
  width: 20px;
  text-align: center;
}

.sidebar a .step-num {
  background: var(--border-soft);
  color: var(--text-muted);
  font-size: 10px;
  font-weight: 700;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-left: auto;
}

.sidebar a.active .step-num {
  background: var(--accent);
  color: white;
}

/* --- MAIN CONTENT --- */
.main {
  padding: 36px 52px;
  background: var(--white);
}

/* --- PAGE HEADER --- */
.page-header {
  margin-bottom: 36px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-soft);
}

.page-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
}

.page-title {
  font-size: 36px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--accent);
  margin-bottom: 10px;
  border-bottom: 2px solid var(--title-border);
  padding-bottom: 10px;
}

.page-title span { color: var(--text-primary); }

.page-meta {
  color: var(--text-muted);
  font-size: 13px;
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.page-meta span { display: flex; align-items: center; gap: 6px; }

/* --- SECTION HEADER --- */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border-soft);
}

.section-desc {
  color: var(--text-secondary);
  font-size: 15px;
  margin-bottom: 24px;
  max-width: 680px;
}

/* --- CALLOUT BOXES --- */
.instructor-note {
  background-color: var(--title-top);
  border: 1px solid var(--title-border);
  border-left: 4px solid var(--accent);
  border-radius: 0 4px 4px 0;
  padding: 14px 18px;
  margin-bottom: 20px;
  font-size: 14px;
}

.instructor-note strong {
  display: block;
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.instructor-note p { color: var(--text-secondary); margin: 0; }

.safety-note {
  background-color: #fff5f5;
  border: 1px solid #ffcccc;
  border-left: 4px solid var(--red);
  border-radius: 0 4px 4px 0;
  padding: 14px 18px;
  margin-bottom: 20px;
  font-size: 14px;
}

.safety-note strong {
  display: block;
  color: var(--red-dark);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.tip-note {
  background-color: #f0fff4;
  border: 1px solid #c8e6c9;
  border-left: 4px solid var(--green);
  border-radius: 0 4px 4px 0;
  padding: 14px 18px;
  margin-bottom: 20px;
  font-size: 14px;
  color: var(--text-secondary);
}

.tip-note strong {
  display: block;
  color: var(--green);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 4px;
}

/* --- CARDS --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 18px 20px;
  margin: 8px 0;
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}

.card-accent {
  background: var(--white);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  padding: 18px 20px;
  margin: 8px 0;
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}

.card-icon {
  font-size: 26px;
  margin-bottom: 10px;
}

.card-title {
  color: var(--accent);
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-soft);
}

.card p { color: var(--text-secondary); font-size: 13px; line-height: 1.5; margin: 0; }

/* --- PANEL (gradient title bar) --- */
.panel { border: 1px solid var(--border); border-radius: 6px; overflow: hidden; margin: 8px 0; }

.panel-title {
  background: linear-gradient(to bottom, var(--title-top), var(--title-bottom));
  border-bottom: 1px solid var(--title-border);
  padding: 6px 14px;
  font-weight: 700;
  font-size: 13px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.panel-body { background: var(--surface); padding: 14px; }

/* --- STEPS --- */
.steps { margin-bottom: 24px; }

.step {
  display: flex;
  gap: 16px;
  margin-bottom: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--title-border);
  border-radius: 0 6px 6px 0;
  padding: 14px 18px;
}

.step-number {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  min-width: 28px;
  line-height: 1;
  margin-top: 2px;
}

.step-number.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.logo:hover { color: var(--accent); }

.step-label {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.step-body { color: var(--text-secondary); font-size: 14px; }

.step-body ul {
  margin: 6px 0 0 16px;
  list-style: disc;
}

.step-body li { margin-bottom: 2px; }

/* --- TABLES --- */
table {
  border-collapse: collapse;
  width: 100%;
  margin-bottom: 24px;
  font-size: 15px;
}

th {
  text-align: left;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-primary);
  background: linear-gradient(to bottom, var(--title-top), var(--title-bottom));
  border-bottom: 2px solid var(--title-border);
  padding: 10px 14px;
}

td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: top;
}

tr:nth-child(even) td { background-color: var(--surface); }
tr:hover td { background-color: var(--title-top); }

td.topic { color: var(--text-primary); font-weight: 500; }

td.time {
  color: var(--accent);
  font-weight: 600;
  white-space: nowrap;
}

td .badge {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 2px;
  margin-top: 4px;
}

.badge-hands   { background: #C8E6C9; color: var(--green);  border: 1px solid #81C784; }
.badge-discuss { background: var(--title-top); color: var(--accent); border: 1px solid var(--title-border); }
.badge-demo    { background: #fffbeb; color: #a07000; border: 1px solid #f0d060; }

/* --- SPEC TABLE --- */
.spec-table td:first-child { color: var(--text-primary); font-weight: 500; width: 40%; }
.spec-table td:last-child  { color: var(--accent); font-size: 15px; font-weight: 600; }

/* --- CHECKLIST --- */
.checklist { list-style: none; margin-bottom: 24px; }

.checklist li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 9px 0;
  border-bottom: 1px solid var(--border-soft);
  color: var(--text-secondary);
  font-size: 14px;
  cursor: pointer;
  transition: color 0.15s;
}

.checklist li:hover { color: var(--text-primary); }

.checklist li input[type="checkbox"] {
  margin-top: 2px;
  accent-color: var(--accent);
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  cursor: pointer;
}

.checklist li label { cursor: pointer; flex: 1; }
.checklist li.checked label { text-decoration: line-through; color: var(--text-muted); }

/* --- REFRIGERANT CYCLE DIAGRAM --- */
.cycle-diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 28px;
  margin-bottom: 24px;
  text-align: center;
}

.cycle-svg-wrap { max-width: 600px; margin: 0 auto; }

/* --- EXERCISE BLOCK --- */
.exercise-block {
  background: var(--white);
  border: 1px solid var(--border);
  border-top: 3px solid var(--green-light);
  border-radius: 6px;
  padding: 18px 22px;
  margin-bottom: 16px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.06);
}

.exercise-block .ex-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.exercise-block .ex-icon { font-size: 20px; }

.exercise-block .ex-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
}

.exercise-block .ex-machine {
  margin-left: auto;
  font-size: 11px;
  color: var(--green);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: #C8E6C9;
  border: 1px solid #81C784;
  padding: 3px 10px;
  border-radius: 3px;
}

.exercise-block ul {
  margin-left: 20px;
  color: var(--text-secondary);
  font-size: 14px;
}

.exercise-block li { margin-bottom: 4px; }

.exercise-block .ex-goal {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border-soft);
  font-size: 13px;
  color: var(--text-muted);
  font-style: italic;
}

/* --- TWO COLUMN --- */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 24px; }

/* --- NAV BUTTONS --- */
.nav-buttons {
  display: flex;
  justify-content: space-between;
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--border-soft);
}

/* --- BUTTONS --- */
.btn {
  background-color: #F0F0F0;
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 8px 20px;
  font-family: inherit;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn:hover  { background-color: #E0E0E0; border-color: var(--accent); }
.btn:active { background-color: #D0D0D0; }

.btn-primary {
  background-color: var(--accent);
  color: white;
  border: 1px solid var(--accent);
  border-radius: 3px;
  padding: 8px 22px;
  font-family: inherit;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-primary:hover  { background-color: var(--accent-dark); border-color: var(--accent-dark); }
.btn-primary:active { background-color: #005fa3; }

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 8px 20px;
  font-family: inherit;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-ghost:hover { background: var(--surface); color: var(--text-primary); border-color: var(--accent); }

.btn-danger {
  background-color: var(--danger-bg);
  color: var(--danger-text);
  border: 1px solid var(--danger-border);
  border-radius: 4px;
  padding: 8px 20px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-danger:hover  { background-color: #ffcccc; border-color: #ff9999; }
.btn-danger:active { background-color: #ffb3b3; }

/* --- TYPOGRAPHY --- */
h1 { color: var(--accent); border-bottom: 2px solid var(--title-border); padding-bottom: 10px; margin-top: 0; margin-bottom: 16px; }
h2 { color: var(--text-primary); font-weight: 700; margin-top: 24px; margin-bottom: 12px; }
h3 { color: var(--text-secondary); font-size: 16px; font-weight: 700; margin: 20px 0 8px; }

p  { margin-bottom: 12px; color: var(--text-secondary); font-size: 15px; }
ul, ol { margin: 8px 0 8px 20px; }
li { margin: 4px 0; color: var(--text-secondary); font-size: 14px; }

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

code {
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 2px 6px;
  border-radius: 3px;
  font-family: Consolas, monospace;
  font-weight: 700;
  font-size: 0.9em;
}

/* --- FORM INPUTS --- */
input[type="text"], input[type="search"], textarea, select {
  width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 3px;
  font-family: inherit;
  font-size: 14px;
  background-color: white;
  transition: border-color 0.15s;
}

input[type="text"]:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0,120,212,0.12);
}

input[type="checkbox"] { accent-color: var(--accent); }

/* --- RESPONSIVE --- */
@media (max-width: 768px) {
  /* Top header bar */
  .site-header {
    padding: 0 16px;
    height: 52px;
    gap: 12px;
  }
  .breadcrumb { display: none; }
  .header-badge { display: none; }
  .logo span { display: none; }

  /* Sidebar becomes a horizontal scroll strip */
  .layout {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
  .sidebar {
    position: static;
    height: auto;
    min-width: 0;
    border-right: none;
    border-bottom: 1px solid var(--border);
    display: flex;
    flex-direction: row;
    overflow-x: auto;
    padding: 0;
    -webkit-overflow-scrolling: touch;
  }
  .sidebar-section-label { display: none; }
  .sidebar a {
    flex-shrink: 0;
    border-left: none;
    border-bottom: 3px solid transparent;
    padding: 10px 14px;
  }
  .sidebar a:hover, .sidebar a.active {
    border-left-color: transparent;
    border-bottom-color: var(--accent);
  }
  .sidebar a .step-num { display: none; }

  /* Page content */
  .main { padding: 20px 16px; min-width: 0; overflow-x: hidden; }
  .page-title { font-size: 26px; }
  .two-col { grid-template-columns: 1fr; }

  /* Tables scroll horizontally rather than overflowing */
  table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}