:root {
  color-scheme: light;
  --ink: #121318;
  --muted: #5d6472;
  --line: #e4e8ef;
  --bg: #ffffff;
  --panel: #f7f9fc;
  --accent: #0a84ff;
  --accent-dark: #075fc0;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(18px);
}

.site-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 860px;
  margin: 0 auto;
  padding: 12px 20px;
}

.site-nav-brand {
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.site-nav-menu {
  position: relative;
}

.site-nav-menu summary {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--ink);
  font-weight: 700;
  list-style: none;
  cursor: pointer;
}

.site-nav-menu summary::-webkit-details-marker {
  display: none;
}

.site-nav-menu summary::after {
  content: "";
  width: 7px;
  height: 7px;
  margin-left: 8px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: translateY(-2px) rotate(45deg);
}

.site-nav-menu[open] summary::after {
  transform: translateY(2px) rotate(225deg);
}

.site-nav-dropdown {
  position: absolute;
  right: 0;
  top: calc(100% + 8px);
  width: min(320px, calc(100vw - 32px));
  max-height: min(72vh, 620px);
  overflow-y: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 8px;
  background: #fff;
  box-shadow: 0 18px 42px rgba(18, 19, 24, 0.14);
}

.site-nav-dropdown a {
  display: block;
  border-radius: 8px;
  padding: 10px;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.25;
  text-decoration: none;
}

.site-nav-dropdown a span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 500;
}

.site-nav-dropdown a:hover,
.site-nav-dropdown a:focus {
  outline: none;
  background: var(--panel);
}

main {
  max-width: 860px;
  margin: 0 auto;
  padding: 44px 20px 72px;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2.1rem, 7vw, 4rem);
  line-height: 1.02;
  letter-spacing: 0;
}

h2 {
  margin: 44px 0 14px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
  font-size: 1.45rem;
  line-height: 1.2;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  letter-spacing: 0;
}

p,
li {
  font-size: 1rem;
}

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

.lede {
  max-width: 700px;
  margin: 0 0 22px;
  color: var(--muted);
  font-size: 1.12rem;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 28px;
}

.pill {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 7px 11px;
  background: var(--panel);
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.92rem;
  white-space: nowrap;
}

.summary,
.summary-card,
.signup,
.signup-card,
.note,
.card,
.contents,
.workout-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
}

.summary-card {
  margin: 28px 0;
}

.summary-card p:last-child,
.signup-card p:last-child,
.workout-card p:last-child {
  margin-bottom: 0;
}

a.card {
  display: block;
  color: var(--ink);
  text-decoration: none;
}

a.card:hover,
a.card:focus {
  border-color: rgba(10, 132, 255, 0.4);
  outline: none;
}

.signup {
  margin: 30px 0;
  border-color: rgba(10, 132, 255, 0.28);
}

.signup-card {
  display: grid;
  gap: 16px;
  margin: 30px 0;
  border-color: rgba(10, 132, 255, 0.28);
}

.signup h2 {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.signup-card h2,
.contents h2 {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.signup-form {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}

.signup-form-row {
  display: grid;
  gap: 10px;
}

@media (min-width: 620px) {
  .signup-form-row {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
}

.signup label {
  display: block;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.signup input[type="email"] {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  background: #fff;
  color: var(--ink);
  font: inherit;
}

.signup input[type="email"]:focus {
  outline: 3px solid rgba(10, 132, 255, 0.18);
  border-color: var(--accent);
}

.signup-card form {
  display: grid;
  gap: 10px;
}

.signup-card input[type="email"] {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  background: #fff;
  color: var(--ink);
  font: inherit;
}

.signup-card input[type="email"]:focus {
  outline: 3px solid rgba(10, 132, 255, 0.18);
  border-color: var(--accent);
}

.signup-card button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  border: 0;
  border-radius: 8px;
  padding: 11px 15px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.signup-card button:hover,
.signup-card button:focus {
  background: var(--accent-dark);
}

.signup-note,
.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  border: 0;
  border-radius: 8px;
  padding: 11px 15px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}

.button:focus,
.button:hover {
  background: var(--accent-dark);
}

.grid {
  display: grid;
  gap: 14px;
}

.workout-grid {
  display: grid;
  gap: 14px;
}

@media (min-width: 680px) {
  .grid.two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .workout-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .signup-card {
    grid-template-columns: minmax(0, 1fr) minmax(260px, 320px);
    align-items: center;
  }
}

.workout-row {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}

.workout-row:first-of-type {
  border-top: 0;
}

.reps {
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  white-space: nowrap;
}

.toc {
  columns: 1;
  margin: 0;
  padding-left: 20px;
}

@media (min-width: 680px) {
  .toc {
    columns: 2;
  }
}

.references li {
  margin-bottom: 10px;
}

.contents {
  margin: 30px 0;
}

.contents ol {
  margin-bottom: 0;
  padding-left: 22px;
}

.faq-section details {
  border-top: 1px solid var(--line);
  padding: 14px 0;
}

.faq-section details:first-of-type {
  border-top: 0;
}

.faq-section summary {
  cursor: pointer;
  font-weight: 800;
}