/* ============================================================
   VIM LONGEVITY — H2 Evidence Library — Design Tokens & Components
   Brand aesthetic — mint/teal/deep-blue gradient on near-black,
   single-family typography: Plus Jakarta Sans.
   ============================================================ */

:root,
[data-theme='light'] {
  /* Surfaces */
  --color-bg: #f4faf9;
  --color-surface: #ffffff;
  --color-surface-2: #eef7f6;
  --color-surface-offset: #e1f1ee;
  --color-surface-offset-2: #cfe7e2;
  --color-surface-dynamic: #bddcd5;
  --color-divider: #d7ece7;
  --color-border: #c2ddd6;

  /* Text */
  --color-text: #0a2224;
  --color-text-muted: #4c6d6f;
  --color-text-faint: #86a3a3;
  --color-text-inverse: #f4faf9;

  /* Primary accent — VIM Deep Blue */
  --color-primary: #1e6082;
  --color-primary-hover: #175070;
  --color-primary-active: #12405a;
  --color-primary-highlight: #d7ecf2;

  /* Functional tag hues */
  --color-blue: #4b94a2;
  --color-blue-highlight: #d9eeec;
  --color-purple: #5b4be0;
  --color-purple-highlight: #e5e1fb;
  --color-warning: #a3660c;
  --color-warning-highlight: #f0e0c4;
  --color-success: #3a7a3e;
  --color-success-highlight: #d6e9d3;
  --color-error: #a52f4e;
  --color-error-highlight: #f0d3dc;

  /* Brand gradient (darkened for light-bg contrast) */
  --brand-grad: linear-gradient(100deg, #2f7f8c, #1e6082 55%, #12405a);

  --radius-sm: 0.375rem;
  --radius-md: 0.625rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  --shadow-sm: 0 1px 2px oklch(0.2 0.03 210 / 0.06);
  --shadow-md: 0 6px 16px oklch(0.2 0.03 210 / 0.08);
  --shadow-lg: 0 16px 40px oklch(0.2 0.03 210 / 0.14);

  --content-narrow: 640px;
  --content-default: 980px;
  --content-wide: 1240px;
  --content-full: 100%;

  --font-display: 'Plus Jakarta Sans', 'Segoe UI', sans-serif;
  --font-body: 'Plus Jakarta Sans', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

[data-theme='dark'] {
  --color-bg: #05070b;
  --color-surface: #0b0e14;
  --color-surface-2: #10141b;
  --color-surface-offset: #141a22;
  --color-surface-offset-2: #1a212b;
  --color-surface-dynamic: #212a36;
  --color-divider: #1c232c;
  --color-border: #2a333f;

  --color-text: #f4f7fa;
  --color-text-muted: #97a3b4;
  --color-text-faint: #6b7688;
  --color-text-inverse: #05070b;

  --color-primary: #80d0c7;
  --color-primary-hover: #97dad2;
  --color-primary-active: #64c0b5;
  --color-primary-highlight: #16302d;

  --color-blue: #4b94a2;
  --color-blue-highlight: #14282c;
  --color-purple: #8f7ff2;
  --color-purple-highlight: #211c3f;
  --color-warning: #e0a94f;
  --color-warning-highlight: #3a2c17;
  --color-success: #7fbf83;
  --color-success-highlight: #1e3320;
  --color-error: #e07996;
  --color-error-highlight: #3a1e26;

  --brand-grad: linear-gradient(100deg, #80d0c7, #4b94a2 55%, #1e6082);

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.3);
  --shadow-md: 0 6px 16px oklch(0 0 0 / 0.35);
  --shadow-lg: 0 16px 40px oklch(0 0 0 / 0.5);
}

/* ============ Type Scale ============ */
:root {
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.1rem);
  --text-2xl: clamp(1.9rem, 1.3rem + 2.5vw, 3.1rem);

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;
}

/* ============ Global ============ */
body {
  background-image:
    radial-gradient(circle at 12% 8%, oklch(from var(--color-primary) l c h / 0.08), transparent 45%),
    radial-gradient(circle at 88% 0%, oklch(from var(--color-blue) l c h / 0.06), transparent 40%);
  background-attachment: fixed;
}

.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}
.container--narrow {
  max-width: var(--content-default);
}

section {
  padding-block: clamp(var(--space-12), 7vw, var(--space-24));
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  letter-spacing: -0.01em;
}

a {
  color: var(--color-primary);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
}
.eyebrow::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--color-primary);
}

.section-title {
  font-size: var(--text-xl);
  font-weight: 650;
  margin-block: var(--space-3) var(--space-4);
}
.section-lede {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 68ch;
}
.section-head {
  margin-bottom: var(--space-10);
}

/* ============ Header ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: oklch(from var(--color-bg) l c h / 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-divider);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  padding-block: var(--space-3);
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-text);
  white-space: nowrap;
  text-decoration: none;
}
.brand__logo {
  height: 32px;
  width: auto;
  flex-shrink: 0;
  display: block;
}
.brand__text small {
  display: block;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  overflow-x: auto;
  scrollbar-width: none;
  flex: 1;
  justify-content: center;
}
.main-nav::-webkit-scrollbar { display: none; }
.main-nav a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-full);
  white-space: nowrap;
}
.main-nav a:hover {
  color: var(--color-text);
  background: var(--color-surface-offset);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}
.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  background: var(--color-surface);
}
.icon-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.nav-toggle { display: none; }
.icon-btn svg { width: 18px; height: 18px; }

/* ============ Hero ============ */
.hero {
  padding-block: clamp(var(--space-16), 10vw, var(--space-32)) clamp(var(--space-12), 6vw, var(--space-20));
  position: relative;
}
.hero__grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--space-16);
  align-items: center;
}
.hero h1 {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-block: var(--space-5) var(--space-5);
}
.hero h1 em {
  font-style: normal;
  background: var(--brand-grad);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  color: var(--color-primary);
}
.hero p.lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 56ch;
  font-weight: 400;
}
.hero__actions {
  display: flex;
  gap: var(--space-4);
  margin-top: var(--space-8);
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  border: 1px solid transparent;
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-sm);
}
.btn--primary:hover { background: var(--color-primary-hover); }
.btn--ghost {
  border-color: var(--color-border);
  color: var(--color-text);
  background: var(--color-surface);
}
.btn--ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }

.hero__disclaimer {
  margin-top: var(--space-8);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 56ch;
  border-left: 2px solid var(--color-border);
  padding-left: var(--space-3);
}

.hero__visual {
  position: relative;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.molecule-art {
  width: 100%;
  height: 100%;
  max-width: 420px;
}

/* Stat strip */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
  margin-top: var(--space-16);
  padding-top: var(--space-12);
  border-top: 1px solid var(--color-divider);
}
.stat h3 {
  font-size: var(--text-xl);
  color: var(--color-primary);
  font-weight: 700;
}
.stat span {
  display: block;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* ============ Mechanism ============ */
.mech-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
}
.mech-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}
.mech-card__icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-4);
}
.mech-card__icon svg { width: 20px; height: 20px; }
.mech-card h4 {
  font-size: var(--text-base);
  font-weight: 650;
  margin-bottom: var(--space-2);
}
.mech-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.mech-card__links {
  margin-top: var(--space-3);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.mech-card__links a {
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-decoration: none;
  border-bottom: 1px dotted var(--color-primary);
}

/* ============ Launch CTA ============ */
.launch-cta-section {
  padding-block: 0 clamp(var(--space-8), 4vw, var(--space-12));
}
.launch-cta {
  background: var(--color-primary-highlight);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: clamp(var(--space-8), 5vw, var(--space-12));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
  box-shadow: var(--shadow-sm);
}
.launch-cta__copy { max-width: 46ch; }
.launch-cta__copy h2 {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-block: var(--space-3) var(--space-3);
}
.launch-cta__copy p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.launch-cta__action {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}
.launch-cta .btn {
  white-space: nowrap;
}
.launch-cta__note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ============ Caveat callout ============ */
.callout {
  background: var(--color-warning-highlight);
  border: 1px solid oklch(from var(--color-warning) l c h / 0.35);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  gap: var(--space-4);
}
.callout__icon {
  color: var(--color-warning);
  flex-shrink: 0;
  width: 24px;
  height: 24px;
}
.callout h4 {
  font-size: var(--text-base);
  margin-bottom: var(--space-2);
}
.callout ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.callout li::before {
  content: '— ';
  color: var(--color-warning);
}

/* ============ Filter bar ============ */
.filter-bar {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin-bottom: var(--space-10);
  position: sticky;
  top: 64px;
  z-index: 40;
  background: oklch(from var(--color-bg) l c h / 0.92);
  backdrop-filter: blur(10px);
  padding-block: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}
.filter-row {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  align-items: center;
}
.filter-row__label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-faint);
  margin-right: var(--space-2);
  flex-shrink: 0;
}
.pill {
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
}
.pill:hover { border-color: var(--color-primary); color: var(--color-primary); }
.pill.is-active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
  font-weight: 600;
}
.search-input-wrap {
  position: relative;
  flex: 1;
  min-width: 220px;
}
.search-input-wrap svg {
  position: absolute;
  left: var(--space-3);
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--color-text-faint);
}
.search-input {
  width: 100%;
  padding: var(--space-3) var(--space-4) var(--space-3) var(--space-10);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: var(--text-sm);
}
.search-input:focus { border-color: var(--color-primary); outline: none; }
.results-count {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ============ Evidence category groups ============ */
.category-group {
  margin-bottom: var(--space-12);
}
.category-group__head {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-divider);
}
.category-group__head h3 {
  font-size: var(--text-lg);
  font-weight: 650;
}
.category-group__head .count {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  background: var(--color-surface-offset);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
}

.study-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
}
.study-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.study-card__badges {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.badge {
  font-size: var(--text-xs);
  font-weight: 600;
  padding: 0.2em 0.7em;
  border-radius: var(--radius-full);
}
.badge--inhale { background: var(--color-blue-highlight); color: var(--color-blue); }
.badge--water { background: var(--color-primary-highlight); color: var(--color-primary); }
.badge--both { background: var(--color-purple-highlight); color: var(--color-purple); }
.badge--other { background: var(--color-warning-highlight); color: var(--color-warning); }
.badge--year {
  background: var(--color-surface-offset);
  color: var(--color-text-muted);
  font-weight: 500;
}
.study-card h4 {
  font-size: var(--text-base);
  font-weight: 650;
  line-height: 1.35;
}
.study-card__meta {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-style: italic;
}
.study-card__finding {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  flex: 1;
}
.study-card__finding strong {
  color: var(--color-text);
  font-weight: 700;
}
.study-card__source {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  margin-top: auto;
}
.study-card__source svg { width: 12px; height: 12px; }

.empty-state {
  text-align: center;
  padding: var(--space-16) var(--space-6);
  color: var(--color-text-muted);
}

/* ============ Videos ============ */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}
.video-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.video-card__embed {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--color-surface-offset-2);
}
.video-card__embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.video-card__embed--fallback {
  display: flex;
  align-items: center;
  justify-content: center;
  background-size: cover;
  background-position: center;
  position: relative;
  text-decoration: none;
}
.video-card__embed--fallback::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, oklch(0 0 0 / 0.1), oklch(0 0 0 / 0.55));
}
.video-card__play {
  position: relative;
  z-index: 1;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  background: oklch(1 0 0 / 0.92);
  color: var(--color-error);
  display: flex;
  align-items: center;
  justify-content: center;
}
.video-card__play svg { width: 22px; height: 22px; margin-left: 2px; }
.video-card__watch-badge {
  position: absolute;
  z-index: 1;
  bottom: var(--space-3);
  right: var(--space-3);
  background: oklch(0 0 0 / 0.65);
  color: #fff;
  font-size: var(--text-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
}
.video-card__body {
  padding: var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  flex: 1;
}
.video-card__badges {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}
.video-card h4 {
  font-size: var(--text-sm);
  font-weight: 650;
  line-height: 1.35;
}
.video-card__presenter {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.video-card p.desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  flex: 1;
}

/* ============ Reviews table ============ */
.reviews-list {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface);
}
.review-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-divider);
}
.review-row:last-child { border-bottom: none; }
.review-row:hover { background: var(--color-surface-offset); }
.review-row > div {
  flex: 1;
  min-width: 0;
}
.review-row__title {
  font-size: var(--text-sm);
  font-weight: 600;
}
.review-row__meta {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.review-row__link {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  flex-shrink: 0;
}
.review-row__link svg { width: 14px; height: 14px; flex-shrink: 0; }

/* ============ Footer ============ */
.site-footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-16) var(--space-10);
  background: var(--color-surface-2);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: var(--space-10);
}
.footer-grid h5 {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-faint);
  margin-bottom: var(--space-3);
}
.footer-grid a {
  display: block;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  margin-bottom: var(--space-2);
}
.footer-grid a:hover { color: var(--color-primary); }
.footer-disclaimer {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 62ch;
}
.footer-bottom {
  margin-top: var(--space-12);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

/* ============ Responsive ============ */
@media (max-width: 900px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__visual { max-width: 280px; margin-inline: auto; order: -1; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .mech-grid { grid-template-columns: repeat(2, 1fr); }
  .study-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  .launch-cta { flex-direction: column; text-align: center; }
  .launch-cta__action { width: 100%; }
  .launch-cta .btn { width: 100%; justify-content: center; }
}

/* Collapse the primary nav into a hamburger dropdown once it no longer
   fits the header in one row (measured overflow starts ~1050px). */
@media (max-width: 1024px) {
  .site-header__inner { position: relative; }
  .nav-toggle { display: inline-flex; order: 1; }
  .header-actions { order: 2; }
  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    overflow-x: visible;
    flex: none;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    padding: var(--space-2) var(--space-4);
  }
  .main-nav.is-open { display: flex; }
  .main-nav a {
    padding: var(--space-4) var(--space-2);
    border-radius: 0;
    border-bottom: 1px solid var(--color-divider);
    white-space: normal;
  }
  .main-nav a:last-child { border-bottom: none; }
}
@media (max-width: 600px) {
  .mech-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: 1fr; }
  .filter-bar { top: 0; }
  .review-row { flex-direction: column; align-items: flex-start; }
}