/* ========================================================================
   SLR Watch — Static Research Microsite Stylesheet
   ======================================================================== */

/* --- Custom Properties (Light) ---------------------------------------- */
:root {
  /* Surfaces */
  --bg-primary: #FAFAF7;
  --bg-secondary: #F0EFE9;
  --bg-surface: #FFFFFF;
  --bg-surface-raised: #FFFFFF;
  --bg-code: #F5F4EF;
  --bg-nav: rgba(250, 250, 247, 0.85);

  /* Text */
  --text-primary: #1B1B1F;
  --text-secondary: #4A4A56;
  --text-tertiary: #6E6E7A;
  --text-inverse: #FAFAF7;

  /* Accent */
  --accent: #1A365D;
  --accent-light: #2B6CB0;
  --accent-muted: #E8EEF5;
  --accent-hover: #2C5282;

  /* Data colors */
  --data-positive: #276749;
  --data-positive-bg: #C6F6D5;
  --data-negative: #9B2C2C;
  --data-negative-bg: #FED7D7;
  --data-neutral: #975A16;
  --data-neutral-bg: #FEFCBF;

  /* Chart palette */
  --chart-1: #2B6CB0;
  --chart-2: #D69E2E;
  --chart-3: #9B2C2C;
  --chart-4: #276749;
  --chart-dot-fill: #2B6CB0;
  --chart-dot-stroke: #2B6CB0;
  --chart-dot-hollow: transparent;
  --chart-grid: #E2E8F0;
  --chart-axis: #A0AEC0;
  --chart-label: #4A4A56;
  --chart-bg: #FFFFFF;

  /* Borders */
  --border: #E2E8F0;
  --border-strong: #CBD5E0;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.08);

  /* Heatmap */
  --heatmap-pos-strong: #276749;
  --heatmap-pos-light: #C6F6D5;
  --heatmap-neg-strong: #9B2C2C;
  --heatmap-neg-light: #FED7D7;
  --heatmap-zero: var(--bg-surface);
  --heatmap-text-strong: #FFFFFF;
  --heatmap-text-light: var(--text-primary);

  /* Misc */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --transition: 0.25s ease;
  --max-width: 1120px;
  --nav-height: 60px;

  color-scheme: light;
}

/* --- Custom Properties (Dark) ----------------------------------------- */
[data-theme="dark"] {
  --bg-primary: #0D1117;
  --bg-secondary: #161B22;
  --bg-surface: #1C2128;
  --bg-surface-raised: #242A33;
  --bg-code: #1C2128;
  --bg-nav: rgba(13, 17, 23, 0.88);

  --text-primary: #E6EDF3;
  --text-secondary: #8B949E;
  --text-tertiary: #6E7681;
  --text-inverse: #0D1117;

  --accent: #79C0FF;
  --accent-light: #58A6FF;
  --accent-muted: #1A2740;
  --accent-hover: #A5D6FF;

  --data-positive: #3FB950;
  --data-positive-bg: rgba(63,185,80,0.15);
  --data-negative: #F85149;
  --data-negative-bg: rgba(248,81,73,0.15);
  --data-neutral: #D29922;
  --data-neutral-bg: rgba(210,153,34,0.15);

  --chart-1: #58A6FF;
  --chart-2: #D29922;
  --chart-3: #F85149;
  --chart-4: #3FB950;
  --chart-dot-fill: #58A6FF;
  --chart-dot-stroke: #58A6FF;
  --chart-dot-hollow: transparent;
  --chart-grid: #30363D;
  --chart-axis: #484F58;
  --chart-label: #8B949E;
  --chart-bg: #1C2128;

  --border: #30363D;
  --border-strong: #484F58;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.25);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.3);

  --heatmap-pos-strong: #3FB950;
  --heatmap-pos-light: rgba(63,185,80,0.15);
  --heatmap-neg-strong: #F85149;
  --heatmap-neg-light: rgba(248,81,73,0.15);
  --heatmap-zero: var(--bg-surface);
  --heatmap-text-strong: #FFFFFF;
  --heatmap-text-light: var(--text-primary);

  color-scheme: dark;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 24px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img, svg.chart-svg {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--accent-light);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* --- Typography ------------------------------------------------------- */
h1, h2, h3, h4 {
  font-family: 'Source Serif 4', 'Georgia', 'Times New Roman', serif;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2.4rem, 5vw, 3.6rem); }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: 0.6em; }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); margin-bottom: 0.5em; }
h4 { font-size: 1.1rem; margin-bottom: 0.4em; font-weight: 600; }

p { margin-bottom: 1em; }
p:last-child { margin-bottom: 0; }

.label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-light);
}

.lead {
  font-size: 1.15rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.small {
  font-size: 0.875rem;
  color: var(--text-tertiary);
}

.mono {
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
}

/* --- Layout ----------------------------------------------------------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section + .section {
  border-top: 1px solid var(--border);
}

.section-header {
  margin-bottom: 48px;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

/* --- Navigation ------------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: var(--nav-height);
  transition: background-color var(--transition), border-color var(--transition);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-family: 'Source Serif 4', Georgia, serif;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.02em;
}
.nav-brand:hover {
  color: var(--accent-light);
  text-decoration: none;
}
.nav-brand span {
  color: var(--accent-light);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
  background: var(--bg-secondary);
  text-decoration: none;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: color var(--transition), border-color var(--transition), background var(--transition);
  font-size: 1.1rem;
  flex-shrink: 0;
}
.theme-toggle:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
  background: var(--bg-secondary);
}

.nav-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 1.2rem;
}

/* --- Hero ------------------------------------------------------------- */
.hero {
  padding: 72px 0 48px;
  text-align: center;
}

.hero h1 {
  margin-bottom: 16px;
}

.hero .thesis {
  max-width: 740px;
  margin: 0 auto 20px;
  font-size: 1.2rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

.hero .byline {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-tertiary);
  letter-spacing: 0.02em;
}

/* --- Highlight Cards -------------------------------------------------- */
.highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.highlight-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  transition: box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
}
.highlight-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-strong);
}

.highlight-card .stat {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 8px;
}
.highlight-card .stat.positive { color: var(--data-positive); }
.highlight-card .stat.negative { color: var(--data-negative); }
.highlight-card .stat.neutral { color: var(--accent-light); }

.highlight-card .stat-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.highlight-card .stat-desc {
  font-size: 0.82rem;
  color: var(--text-tertiary);
  line-height: 1.5;
}

/* --- Content Card ----------------------------------------------------- */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
}
.card:hover {
  box-shadow: var(--shadow-sm);
}

.card h4 {
  font-family: 'Inter', sans-serif;
}

/* --- Chart Container -------------------------------------------------- */
.chart-wrapper {
  background: var(--chart-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 24px 0;
  transition: background-color var(--transition), border-color var(--transition);
}

.chart-title {
  font-family: 'Inter', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.chart-subtitle {
  font-size: 0.8rem;
  color: var(--text-tertiary);
  margin-bottom: 20px;
}

.chart-container {
  width: 100%;
  overflow-x: auto;
}

.chart-container svg {
  width: 100%;
  height: auto;
  display: block;
}

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.chart-legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.chart-legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.chart-legend-line {
  width: 16px;
  height: 2px;
  flex-shrink: 0;
}

/* --- Heatmap ---------------------------------------------------------- */
.heatmap-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 3px;
  font-size: 0.9rem;
}

.heatmap-table th {
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--text-tertiary);
  text-align: center;
  padding: 10px 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.heatmap-table th:first-child {
  text-align: left;
}

.heatmap-table td {
  text-align: center;
  padding: 14px 12px;
  border-radius: var(--radius-sm);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background-color var(--transition), color var(--transition);
}

.heatmap-table td:first-child {
  text-align: left;
  font-family: 'Inter', sans-serif;
  font-weight: 500;
  color: var(--text-primary);
  background: none;
}

.heatmap-cell-pos-strong {
  background: var(--heatmap-pos-strong);
  color: var(--heatmap-text-strong);
}
.heatmap-cell-pos-light {
  background: var(--heatmap-pos-light);
  color: var(--data-positive);
}
.heatmap-cell-neg-strong {
  background: var(--heatmap-neg-strong);
  color: var(--heatmap-text-strong);
}
.heatmap-cell-neg-light {
  background: var(--heatmap-neg-light);
  color: var(--data-negative);
}
.heatmap-cell-zero {
  background: var(--bg-secondary);
  color: var(--text-tertiary);
}

/* --- Stat Grid -------------------------------------------------------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: background-color var(--transition), border-color var(--transition);
}

.stat-item .stat-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-light);
  margin-bottom: 4px;
}

.stat-item .stat-label {
  font-size: 0.82rem;
  color: var(--text-tertiary);
}

/* --- Caveat / Note ---------------------------------------------------- */
.caveat {
  background: var(--accent-muted);
  border-left: 3px solid var(--accent-light);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin: 24px 0;
  transition: background-color var(--transition), border-color var(--transition), color var(--transition);
}

.caveat strong {
  color: var(--text-primary);
}

/* --- Source Cards ------------------------------------------------------ */
.source-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
}
.source-card:hover {
  box-shadow: var(--shadow-sm);
  border-color: var(--border-strong);
}

.source-card .source-id {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--accent-light);
  margin-bottom: 6px;
}

.source-card h4 {
  margin-bottom: 8px;
  font-size: 1rem;
}

.source-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.source-card .source-meta {
  margin-top: 12px;
  font-size: 0.78rem;
  color: var(--text-tertiary);
  display: flex;
  gap: 16px;
}

/* --- Report Link Cards ------------------------------------------------ */
.report-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  transition: box-shadow var(--transition), border-color var(--transition), background-color var(--transition);
}
.report-card:hover {
  box-shadow: var(--shadow-sm);
  border-color: var(--border-strong);
}

.report-card .report-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-muted);
  border-radius: var(--radius-sm);
  color: var(--accent-light);
}

.report-card .report-body h4 {
  margin-bottom: 4px;
}

.report-card .report-body p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* --- Method Flow ------------------------------------------------------ */
.method-flow {
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
  margin: 32px 0;
}

.method-step {
  display: flex;
  gap: 20px;
  position: relative;
  padding-bottom: 32px;
}

.method-step:last-child {
  padding-bottom: 0;
}

.method-step::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 40px;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.method-step:last-child::before {
  display: none;
}

.method-step .step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent-muted);
  color: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
  border: 2px solid var(--accent-light);
}

.method-step .step-content h4 {
  margin-top: 8px;
}

.method-step .step-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* --- Footer ----------------------------------------------------------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-tertiary);
  transition: border-color var(--transition), color var(--transition);
}

.footer a {
  color: var(--text-secondary);
}

/* --- Scroll Reveal Animation ------------------------------------------ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive ------------------------------------------------------- */
@media (max-width: 900px) {
  .grid-2, .grid-3, .grid-4, .highlights {
    grid-template-columns: 1fr;
  }
  .section { padding: 56px 0; }
  .hero { padding: 56px 0 40px; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-nav);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 12px 24px 20px;
    border-bottom: 1px solid var(--border);
    gap: 4px;
  }
  .nav-links.open {
    display: flex;
  }
  .nav-links a {
    display: block;
    padding: 10px 12px;
  }
  .nav-menu-btn {
    display: flex;
  }
}

@media (max-width: 600px) {
  .container { padding: 0 16px; }
  h1 { font-size: 1.8rem; }
  .hero .thesis { font-size: 1.05rem; }
  .highlight-card { padding: 20px 18px; }
  .highlight-card .stat { font-size: 1.6rem; }
  .chart-wrapper { padding: 16px; }
  .heatmap-table { font-size: 0.8rem; }
  .heatmap-table td { padding: 10px 8px; }
}

/* --- Accessibility ---------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { transition-duration: 0.01ms !important; }
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-primary: #0D1117;
    --bg-secondary: #161B22;
    --bg-surface: #1C2128;
    --bg-surface-raised: #242A33;
    --bg-code: #1C2128;
    --bg-nav: rgba(13, 17, 23, 0.88);
    --text-primary: #E6EDF3;
    --text-secondary: #8B949E;
    --text-tertiary: #6E7681;
    --text-inverse: #0D1117;
    --accent: #79C0FF;
    --accent-light: #58A6FF;
    --accent-muted: #1A2740;
    --accent-hover: #A5D6FF;
    --data-positive: #3FB950;
    --data-positive-bg: rgba(63,185,80,0.15);
    --data-negative: #F85149;
    --data-negative-bg: rgba(248,81,73,0.15);
    --chart-1: #58A6FF;
    --chart-2: #D29922;
    --chart-3: #F85149;
    --chart-4: #3FB950;
    --chart-dot-fill: #58A6FF;
    --chart-dot-stroke: #58A6FF;
    --chart-grid: #30363D;
    --chart-axis: #484F58;
    --chart-label: #8B949E;
    --chart-bg: #1C2128;
    --border: #30363D;
    --border-strong: #484F58;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.25);
    --heatmap-pos-strong: #3FB950;
    --heatmap-pos-light: rgba(63,185,80,0.15);
    --heatmap-neg-strong: #F85149;
    --heatmap-neg-light: rgba(248,81,73,0.15);
    color-scheme: dark;
  }
}

/* --- Focus Styles ----------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--accent-light);
  outline-offset: 2px;
}

/* --- Print ------------------------------------------------------------ */
@media print {
  .nav, .theme-toggle, .scroll-hint, .nav-menu-btn { display: none; }
  .section { padding: 24px 0; }
  .reveal { opacity: 1; transform: none; }
  body { background: white; color: black; font-size: 11pt; }
}

/* --- Two-column content layout --------------------------------------- */
.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 40px;
  align-items: start;
}

.content-with-sidebar .sidebar {
  position: sticky;
  top: calc(var(--nav-height) + 24px);
}

@media (max-width: 900px) {
  .content-with-sidebar {
    grid-template-columns: 1fr;
  }
  .content-with-sidebar .sidebar {
    position: static;
  }
}

/* --- Divider ---------------------------------------------------------- */
.divider {
  height: 1px;
  background: var(--border);
  margin: 48px 0;
}

/* --- Badge ------------------------------------------------------------ */
.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 4px;
  background: var(--accent-muted);
  color: var(--accent-light);
}

/* --- Subsection heading ----------------------------------------------- */
.subsection {
  margin-top: 56px;
}

.subsection:first-child {
  margin-top: 0;
}

/* --- Inline code ------------------------------------------------------ */
code {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85em;
  background: var(--bg-code);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--accent-light);
}

/* --- Lists inside cards ----------------------------------------------- */
.card ul, .source-card ul {
  list-style: none;
  padding: 0;
}
.card ul li, .source-card ul li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 6px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.card ul li::before, .source-card ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-light);
}

/* --- Gap utility ------------------------------------------------------ */
.gap-sm { gap: 12px; }
.gap-md { gap: 24px; }
.gap-lg { gap: 40px; }
.mt-sm { margin-top: 16px; }
.mt-md { margin-top: 32px; }
.mt-lg { margin-top: 48px; }
.mb-sm { margin-bottom: 16px; }
.mb-md { margin-bottom: 32px; }