/* ==========================================================================
   600IQ - QPI Calculator Scoped Stylesheet
   Designed for Vercel-inspired Aesthetics, Exceptional Mobile Responsiveness & High Performance
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design System Tokens & Base Layout Setup
   -------------------------------------------------------------------------- */
:root {
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, monospace;

  /* Colors (Light Theme Defaults) */
  --bg-canvas: #ffffff;
  --bg-canvas-soft: #fafafa;
  --bg-canvas-soft-2: #f5f5f5;
  --bg-card: #ffffff;
  --bg-card-hover: #fafafa;

  --text-primary: #171717;
  --text-secondary: #525252;
  --text-muted: #888888;

  --border-color: #ebebeb;
  --border-hover: #b5b5b5;
  --border-strong: #171717;

  --accent-primary: #171717;
  --accent-text: #ffffff;
  --accent-blue: #0070f3;
  --accent-blue-soft: rgba(0, 112, 243, 0.08);
  --accent-cyan: #50e3c2;
  --accent-violet: #7928ca;
  --accent-green: #10b981;
  --accent-green-soft: rgba(16, 185, 129, 0.1);
  --accent-amber: #f59e0b;
  --accent-red: #ef4444;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 20px rgba(0, 112, 243, 0.12);

  --header-bg: rgba(255, 255, 255, 0.85);
  --badge-bg: #f5f5f5;
  --badge-text: #404040;

  --input-bg: #ffffff;
  --input-border: #e5e5e5;
  --input-placeholder: #9ca3af;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme Overrides */
html[data-theme="dark"] {
  --bg-canvas: #0a0a0a;
  --bg-canvas-soft: #121212;
  --bg-canvas-soft-2: #181818;
  --bg-card: #141414;
  --bg-card-hover: #1f1f1f;

  --text-primary: #f5f5f5;
  --text-secondary: #a3a3a3;
  --text-muted: #737373;

  --border-color: #262626;
  --border-hover: #454545;
  --border-strong: #ffffff;

  --accent-primary: #ffffff;
  --accent-text: #0a0a0a;
  --accent-blue: #0070f3;
  --accent-blue-soft: rgba(0, 112, 243, 0.18);
  --accent-cyan: #50e3c2;
  --accent-violet: #a855f7;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 30px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 25px rgba(0, 112, 243, 0.25);

  --header-bg: rgba(10, 10, 10, 0.85);
  --badge-bg: #222222;
  --badge-text: #d4d4d4;

  --input-bg: #141414;
  --input-border: #262626;
  --input-placeholder: #525252;
}

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

html, body {
  overflow-x: hidden;
  width: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding-bottom: 5rem;
}

.font-mono {
  font-family: var(--font-mono);
}

/* Container Utility */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* --------------------------------------------------------------------------
   2. Sticky Header & Navigation Bar
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-smooth);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.brand-logo {
  font-weight: 800;
  font-size: 1.35rem;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.03em;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.brand-logo span {
  background: linear-gradient(135deg, var(--text-primary), var(--accent-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-primary);
}

.theme-toggle-btn {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--border-hover);
  background: var(--bg-canvas-soft-2);
}

/* --------------------------------------------------------------------------
   3. Main Hero & Page Introduction
   -------------------------------------------------------------------------- */
.main-wrapper {
  max-width: 1050px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem 1.25rem;
}

.hero-section {
  text-align: center;
  margin-bottom: 2.5rem;
}

.hero-title {
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.hero-title span {
  color: var(--accent-blue);
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-violet));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 1.25rem auto;
  line-height: 1.5;
}

.privacy-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid rgba(0, 112, 243, 0.2);
  max-width: 100%;
  word-break: break-word;
}

.privacy-icon {
  font-size: 0.95rem;
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   4. Main Calculator Container & Card UI
   -------------------------------------------------------------------------- */
.calculator-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 3rem;
  transition: border-color var(--transition-smooth);
}

.calculator-controls-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.form-select, .form-input {
  width: 100%;
  height: 2.75rem;
  padding: 0 0.85rem;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  outline: none;
}

.form-select:focus, .form-input:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px var(--accent-blue-soft);
}

.mode-tabs {
  display: flex;
  background: var(--bg-canvas-soft-2);
  padding: 0.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  gap: 0.25rem;
}

.mode-tab {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
}

.mode-tab:hover {
  color: var(--text-primary);
}

.mode-tab.active {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

.scale-legend {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.6rem 1rem;
  margin-bottom: 1.75rem;
  font-size: 0.85rem;
  flex-wrap: wrap;
}

.scale-title {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.scale-chips {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.scale-chip {
  background: var(--bg-canvas-soft-2);
  border: 1px solid var(--border-color);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--text-secondary);
}

/* --------------------------------------------------------------------------
   5. Dynamic Semester & Course Table Styles (Mobile Optimized)
   -------------------------------------------------------------------------- */
.semesters-container {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
  margin-bottom: 1.5rem;
}

.semester-block {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: border-color var(--transition-smooth);
}

/* Semester Header: Flexible & Wrap-Safe */
.semester-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.semester-title-input {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  border: none;
  background: transparent;
  font-family: var(--font-sans);
  padding: 0.2rem 0.4rem;
  border-radius: var(--radius-sm);
  outline: none;
  transition: background var(--transition-fast);
  flex: 1 1 160px;
  min-width: 120px;
  max-width: 100%;
}

.semester-title-input:hover, .semester-title-input:focus {
  background: var(--bg-card);
}

/* Subtotal Badge: Responsive & Overflow-Proof */
.semester-subtotal-badge {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  white-space: nowrap;
  max-width: 100%;
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
}

.semester-subtotal-badge strong {
  color: var(--accent-blue);
}

.course-table-header {
  display: grid;
  grid-template-columns: 2.5fr 1fr 1.25fr 40px;
  gap: 0.75rem;
  padding: 0 0.5rem 0.5rem 0.5rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.course-rows-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.course-row {
  display: grid;
  grid-template-columns: 2.5fr 1fr 1.25fr 40px;
  gap: 0.75rem;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.course-row:focus-within {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-sm);
}

.course-row .form-input, .course-row .form-select {
  height: 2.35rem;
  font-size: 0.9rem;
}

.btn-remove-row {
  width: 2.35rem;
  height: 2.35rem;
  border: 1px solid var(--border-color);
  background: var(--bg-canvas-soft);
  color: var(--text-muted);
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
}

.btn-remove-row:hover {
  background: #fee2e2;
  color: var(--accent-red);
  border-color: #fca5a5;
}

html[data-theme="dark"] .btn-remove-row:hover {
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
  border-color: rgba(239, 68, 68, 0.4);
}

.table-actions-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  height: 2.5rem;
  padding: 0 1.25rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  text-decoration: none;
}

.btn-primary {
  background: var(--text-primary);
  color: var(--bg-canvas);
  border-color: var(--text-primary);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--bg-canvas-soft-2);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-canvas-soft);
  border-color: var(--border-hover);
}

.btn-outline {
  background: transparent;
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-outline:hover {
  background: var(--bg-canvas-soft);
  border-color: var(--border-hover);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: var(--accent-red);
  background: rgba(239, 68, 68, 0.08);
}

.hidden {
  display: none !important;
}

/* --------------------------------------------------------------------------
   6. Results Dashboard & Summary Display
   -------------------------------------------------------------------------- */
.results-dashboard {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.result-card {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.result-card.main-qpi {
  background: linear-gradient(135deg, var(--bg-canvas-soft-2), var(--bg-canvas-soft));
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
}

.result-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.result-value {
  font-size: clamp(1.8rem, 6vw, 2.25rem);
  font-weight: 900;
  font-family: var(--font-mono);
  color: var(--text-primary);
  line-height: 1.1;
  margin-bottom: 0.25rem;
}

.result-card.main-qpi .result-value {
  font-size: clamp(2.2rem, 8vw, 2.75rem);
  color: var(--accent-blue);
}

.result-subtext {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.export-actions-bar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}

/* Breakdown Card */
.breakdown-card {
  background: var(--bg-canvas-soft-2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
}

.breakdown-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.breakdown-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.breakdown-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.breakdown-content {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.breakdown-placeholder {
  font-family: var(--font-sans);
  color: var(--text-muted);
  font-style: italic;
  font-size: 0.9rem;
}

.breakdown-item {
  padding: 0.35rem 0;
  border-bottom: 1px dashed var(--border-color);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
}

.breakdown-divider {
  border-top: 2px solid var(--border-color);
  margin: 0.75rem 0;
}

.breakdown-totals {
  font-weight: 700;
  color: var(--text-primary);
}

.breakdown-final-formula {
  margin-top: 0.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  color: var(--accent-blue);
  font-weight: 700;
  font-size: 0.95rem;
  word-break: break-word;
}

/* Planner Box */
.planner-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.planner-header {
  margin-bottom: 1.25rem;
}

.planner-title-group h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.2rem;
}

.planner-subtitle {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.planner-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.planner-result-box {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  word-break: break-word;
}

.planner-status-msg strong {
  color: var(--text-primary);
}

.planner-status-msg .highlight-target {
  color: var(--accent-blue);
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   7. Premium Redesigned Educational & Blog Content Cards
   -------------------------------------------------------------------------- */
.content-section {
  max-width: 950px;
  margin: 0 auto 4rem auto;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.content-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-smooth), box-shadow var(--transition-smooth);
}

.content-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.content-card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-bottom: 1.25rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.card-badge-icon {
  font-size: 1.6rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  background: var(--bg-canvas-soft-2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  flex-shrink: 0;
}

.content-card-header h2 {
  font-size: clamp(1.2rem, 4vw, 1.45rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.3;
}

.content-card-body {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.75;
}

.content-card-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 1.75rem 0 0.85rem 0;
}

.content-card-body p {
  margin-bottom: 1.25rem;
}

.content-card-body p:last-child {
  margin-bottom: 0;
}

.content-card-body code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background: var(--bg-canvas-soft-2);
  border: 1px solid var(--border-color);
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
}

.formula-box {
  background: var(--bg-canvas-soft-2);
  border-left: 4px solid var(--accent-blue);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-primary);
  word-break: break-word;
}

.formula-line {
  margin-bottom: 0.5rem;
}

.formula-line:last-child {
  margin-bottom: 0;
}

.formula-label {
  color: var(--accent-blue);
  font-weight: 700;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 1.5rem 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  -webkit-overflow-scrolling: touch;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.9rem;
}

.data-table th, .data-table td {
  padding: 0.85rem 1.1rem;
  border-bottom: 1px solid var(--border-color);
  white-space: nowrap;
}

.data-table th {
  background: var(--bg-canvas-soft-2);
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.data-table td {
  color: var(--text-secondary);
}

.data-table tbody tr:hover {
  background: var(--bg-canvas-soft);
}

.data-table tfoot td {
  background: var(--bg-canvas-soft-2);
  font-weight: 700;
  color: var(--text-primary);
}

.scale-comparison-table td:first-child {
  font-weight: 700;
}

.badge-grade {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
}

.grade-a { background: rgba(16, 185, 129, 0.15); color: #059669; }
.grade-bplus { background: rgba(0, 112, 243, 0.15); color: #0284c7; }

.example-result-card {
  background: var(--bg-canvas-soft-2);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-top: 1.5rem;
}

.example-header {
  background: var(--bg-canvas-soft);
  padding: 0.6rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.example-body {
  padding: 1.25rem;
}

.example-math {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--text-primary);
  word-break: break-word;
}

.qpi-highlight {
  color: var(--accent-blue);
  font-weight: 800;
  font-size: 1.1rem;
}

.styled-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin-top: 1rem;
}

.list-item-card {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.list-item-icon {
  flex-shrink: 0;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
  font-weight: 800;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.impact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin-top: 1.25rem;
}

.impact-box {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.impact-badge {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--accent-blue);
  margin-bottom: 0.5rem;
}

.impact-box p {
  margin: 0;
  font-size: 0.9rem;
}

.university-links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.uni-card {
  background: var(--bg-canvas-soft);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.uni-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.uni-badge {
  font-size: 0.75rem;
  font-weight: 800;
  color: var(--accent-blue);
  background: var(--accent-blue-soft);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  margin-bottom: 0.5rem;
}

.uni-card h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.uni-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0;
  line-height: 1.5;
}

/* --------------------------------------------------------------------------
   8. Premium FAQ Accordion Section
   -------------------------------------------------------------------------- */
.faq-card-wrapper {
  margin-bottom: 0;
}

.faq-accordion {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-item.open {
  border-color: var(--accent-blue);
  box-shadow: 0 4px 16px rgba(0, 112, 243, 0.08);
}

.faq-header {
  padding: 1.1rem 1.35rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  background: var(--bg-card);
  transition: background var(--transition-fast);
}

.faq-header:hover {
  background: var(--bg-canvas-soft-2);
}

.faq-q-title {
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.faq-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 800;
  background: var(--accent-blue-soft);
  color: var(--accent-blue);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.faq-icon {
  font-size: 0.75rem;
  color: var(--text-muted);
  transition: transform 0.25s ease, color 0.25s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(180deg);
  color: var(--accent-blue);
}

.faq-body {
  padding: 0.85rem 1.35rem 1.25rem 1.35rem;
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.7;
  border-top: 1px dashed var(--border-color);
  background: var(--bg-canvas-soft);
  display: none;
  word-break: break-word;
}

.faq-item.open .faq-body {
  display: block;
}

/* --------------------------------------------------------------------------
   9. Related Tools Section
   -------------------------------------------------------------------------- */
.related-tools-section {
  border-top: 1px solid var(--border-color);
  padding-top: 3rem;
  margin-top: 3rem;
}

.related-tools-section h2 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
}

.related-tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

.related-tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-decoration: none;
  color: var(--text-primary);
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}

.related-tool-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.related-tool-icon {
  font-size: 1.5rem;
}

.related-tool-title {
  font-weight: 700;
  font-size: 1rem;
}

.related-tool-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* --------------------------------------------------------------------------
   10. Standard 600IQ Premium Site Footer
   -------------------------------------------------------------------------- */
.site-footer {
  background: var(--bg-canvas-soft);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2.5rem 0;
  margin-top: 5rem;
  font-size: 0.9rem;
}

.footer-container {
  display: flex;
  justify-content: space-between;
  gap: 3rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.footer-brand {
  max-width: 340px;
}

.logo-badge {
  font-weight: 900;
  font-size: 1.5rem;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.logo-number { color: var(--text-primary); }
.logo-letters { color: var(--accent-blue); }

.footer-tagline {
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.5;
  margin-bottom: 1.25rem;
}

.footer-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3rem 0.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.status-indicator {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
}

.footer-links-group {
  display: flex;
  gap: 4rem;
  flex-wrap: wrap;
}

.footer-heading {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.1rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  transition: color var(--transition-fast), transform var(--transition-fast);
  display: inline-block;
}

.footer-links a:hover {
  color: var(--text-primary);
  transform: translateX(2px);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.copyright {
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   11. Floating Mobile QPI Bar & Toast Notifications
   -------------------------------------------------------------------------- */
.floating-qpi-bar {
  position: fixed;
  bottom: 1.25rem;
  right: 1.25rem;
  z-index: 90;
  background: var(--text-primary);
  color: var(--bg-canvas);
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.floating-qpi-bar:hover {
  transform: scale(1.04);
}

.floating-qpi-bar strong {
  color: var(--accent-cyan);
  font-family: var(--font-mono);
}

@media (min-width: 900px) {
  .floating-qpi-bar {
    display: none;
  }
}

.toast-msg {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text-primary);
  color: var(--bg-canvas);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  z-index: 200;
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease;
}

.toast-msg.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* --------------------------------------------------------------------------
   12. Comprehensive Mobile Responsive Breakpoints
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
  .calculator-controls-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .results-dashboard {
    grid-template-columns: 1fr;
    gap: 0.85rem;
  }

  .planner-grid {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .site-footer {
    padding: 2.5rem 0 1.5rem 0;
    margin-top: 3rem;
  }

  .footer-container {
    flex-direction: column;
    gap: 2rem;
    padding-bottom: 1.5rem;
  }

  .footer-brand {
    max-width: 100%;
  }

  .footer-links-group {
    gap: 2rem;
    flex-direction: column;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    padding-top: 1.25rem;
  }
}

@media (max-width: 600px) {
  .main-wrapper {
    padding: 1.25rem 0.85rem 3rem 0.85rem;
  }

  .container {
    padding: 0 0.85rem;
  }

  .header-container {
    padding: 0 0.85rem;
  }

  .calculator-card {
    padding: 1.25rem 0.85rem;
    border-radius: var(--radius-md);
  }

  .course-table-header {
    display: none;
  }

  .course-row {
    grid-template-columns: 1fr 1fr 38px;
    grid-template-areas:
      "name name remove"
      "units grade remove";
    gap: 0.5rem;
    padding: 0.65rem;
  }

  .course-name-col { grid-area: name; }
  .course-units-col { grid-area: units; }
  .course-grade-col { grid-area: grade; }
  .course-remove-col { grid-area: remove; justify-self: center; align-self: center; }

  .course-row .form-input, .course-row .form-select {
    height: 2.35rem;
    font-size: 0.85rem;
    padding: 0 0.6rem;
  }

  .btn-remove-row {
    width: 2.25rem;
    height: 2.25rem;
    font-size: 0.85rem;
  }

  .breakdown-card {
    padding: 1rem;
  }

  .breakdown-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.15rem;
    font-size: 0.82rem;
  }

  .breakdown-final-formula {
    font-size: 0.82rem;
    padding: 0.6rem 0.75rem;
  }

  .planner-card {
    padding: 1rem;
  }

  .planner-result-box {
    padding: 0.85rem;
    font-size: 0.85rem;
  }

  .content-card {
    padding: 1.1rem;
    border-radius: var(--radius-md);
  }

  .content-card-header {
    padding-bottom: 0.85rem;
    margin-bottom: 1rem;
    gap: 0.5rem;
  }

  .card-badge-icon {
    width: 2.25rem;
    height: 2.25rem;
    font-size: 1.25rem;
  }

  .content-card-body {
    font-size: 0.9rem;
    line-height: 1.65;
  }

  .formula-box {
    padding: 0.85rem 1rem;
    font-size: 0.82rem;
  }

  .data-table th, .data-table td {
    padding: 0.6rem 0.65rem;
    font-size: 0.8rem;
  }

  .impact-grid, .university-links-grid, .related-tools-grid {
    grid-template-columns: 1fr;
    gap: 0.85rem;
  }

  .faq-header {
    padding: 0.85rem 1rem;
  }

  .faq-q-title {
    font-size: 0.88rem;
    line-height: 1.4;
  }

  .faq-num {
    font-size: 0.7rem;
    padding: 0.1rem 0.4rem;
  }

  .faq-body {
    padding: 0.75rem 1rem 1rem 1rem;
    font-size: 0.85rem;
    line-height: 1.6;
  }
}

@media (max-width: 500px) {
  .mode-tabs {
    flex-wrap: wrap;
    gap: 0.25rem;
  }

  .mode-tab {
    font-size: 0.78rem;
    padding: 0.45rem 0.4rem;
    flex: 1 1 calc(50% - 0.25rem);
  }

  .mode-tab[data-mode="annual"] {
    flex: 1 1 100%;
  }

  .table-actions-bar {
    gap: 0.5rem;
  }

  .table-actions-bar .btn {
    flex: 1 1 calc(50% - 0.5rem);
    font-size: 0.82rem;
    padding: 0 0.65rem;
    height: 2.35rem;
  }

  .table-actions-bar #clear-all-btn {
    flex: 1 1 100%;
  }

  .export-actions-bar {
    flex-direction: column;
    width: 100%;
    gap: 0.5rem;
  }

  .export-actions-bar .btn {
    width: 100%;
  }
}

@media (max-width: 480px) {
  .semester-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.4rem;
  }

  .semester-title-input {
    width: 100%;
  }

  .semester-subtotal-badge {
    align-self: flex-start;
    font-size: 0.75rem;
    padding: 0.2rem 0.55rem;
  }
}

@media (max-width: 360px) {
  .course-row {
    grid-template-columns: 1fr 34px;
    grid-template-areas:
      "name remove"
      "units remove"
      "grade remove";
  }
}