/* ---------- Color themes ---------- */
:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-2: #f0f2f5;
  --border: #e3e6eb;
  --text: #12141a;
  --muted: #5f6675;
  --accent: #a3e635;
  --accent-strong: #4d7c0f;
  --on-accent: #142004;
  --result-bg: linear-gradient(145deg, #12141a 0%, #1f2a10 100%);
  --result-text: #ffffff;
  --result-muted: #b6bcc8;
  --result-accent: #c6ff3d;
  --error: #d63c3c;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.04), 0 8px 24px rgba(16, 24, 40, 0.06);
  --radius: 20px;
  --radius-sm: 12px;
  --font-body: "Inter", "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  --font-display: "Barlow Condensed", "Arial Narrow", "Inter", sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0c0d11;
    --surface: #15171d;
    --surface-2: #1c1f27;
    --border: #262a34;
    --text: #f2f3f6;
    --muted: #979dab;
    --accent: #c6ff3d;
    --accent-strong: #c6ff3d;
    --on-accent: #142004;
    --result-bg: linear-gradient(145deg, #1a2309 0%, #15171d 100%);
    --result-text: #ffffff;
    --result-muted: #a3a9b6;
    --result-accent: #c6ff3d;
    --error: #ff7070;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 10px 30px rgba(0, 0, 0, 0.25);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #0c0d11;
  --surface: #15171d;
  --surface-2: #1c1f27;
  --border: #262a34;
  --text: #f2f3f6;
  --muted: #979dab;
  --accent: #c6ff3d;
  --accent-strong: #c6ff3d;
  --on-accent: #142004;
  --result-bg: linear-gradient(145deg, #1a2309 0%, #15171d 100%);
  --result-text: #ffffff;
  --result-muted: #a3a9b6;
  --result-accent: #c6ff3d;
  --error: #ff7070;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 10px 30px rgba(0, 0, 0, 0.25);
  color-scheme: dark;
}

/* ---------- Base ---------- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.3s ease, color 0.3s ease;
}

button {
  font: inherit;
  cursor: pointer;
}

:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg); /* fallback for older browsers */
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.logo-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--on-accent);
}

.logo-text {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: 0.01em;
  text-transform: uppercase;
}

.logo-text span {
  color: var(--muted);
  font-weight: 600;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Main menu: a dropdown on phones, a row of links on larger screens */
.site-nav {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  display: none;
  flex-direction: column;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  padding: 8px 16px 16px;
}

.site-nav.open {
  display: flex;
  animation: slideIn 0.2s ease;
}

.site-nav a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  padding: 12px 8px;
  border-radius: 10px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.site-nav a:hover {
  background: var(--surface-2);
}

.site-nav a[aria-current="page"] {
  color: var(--accent-strong);
}

.menu-toggle {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
}

.menu-toggle .icon-close,
.menu-toggle[aria-expanded="true"] .icon-menu {
  display: none;
}

.menu-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  transition: transform 0.2s ease, background-color 0.3s ease;
}

.theme-toggle:hover {
  transform: rotate(15deg);
}

.theme-toggle svg {
  grid-area: 1 / 1;
  transition: opacity 0.3s ease, transform 0.4s ease;
}

/* Show the moon in light mode, the sun in dark mode */
.icon-sun { opacity: 0; transform: rotate(-90deg) scale(0.6); }
.icon-moon { opacity: 1; transform: none; }

:root[data-theme="dark"] .icon-sun { opacity: 1; transform: none; }
:root[data-theme="dark"] .icon-moon { opacity: 0; transform: rotate(90deg) scale(0.6); }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { opacity: 1; transform: none; }
  :root:not([data-theme="light"]) .icon-moon { opacity: 0; transform: rotate(90deg) scale(0.6); }
}

/* ---------- Layout ---------- */
.container {
  flex: 1;
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding: 32px 16px 56px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero {
  text-align: center;
  max-width: 620px;
  margin: 8px auto 12px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-strong);
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  border-radius: 999px;
  padding: 5px 12px;
  margin-bottom: 16px;
}

h1 {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 10vw, 4rem);
  font-weight: 800;
  line-height: 1;
  text-transform: uppercase;
  letter-spacing: -0.005em;
}

.highlight {
  color: var(--accent-strong);
}

.subtitle {
  color: var(--muted);
  font-size: 1.05rem;
  margin-top: 14px;
}

.top-grid {
  display: grid;
  gap: 20px;
}

/* ---------- Cards ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: var(--shadow);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.card-head {
  margin-bottom: 18px;
}

h2 {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.card-sub {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 2px;
}

/* ---------- Inputs ---------- */
.inputs {
  display: grid;
  gap: 20px;
}

.field label,
.field .label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.hint {
  color: var(--muted);
  font-weight: 500;
  font-size: 0.8rem;
}

.input-wrap {
  position: relative;
}

input {
  width: 100%;
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  background: var(--surface-2);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  padding-block: 10px;
  padding-inline: 16px 70px;
  outline: none;
  transition: border-color 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

input::placeholder {
  color: var(--muted);
  opacity: 0.45;
}

input:focus {
  border-color: var(--accent-strong);
  background: var(--surface);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 25%, transparent);
}

input.invalid {
  border-color: var(--error);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--error) 15%, transparent);
}

.input-suffix {
  position: absolute;
  inset-inline-end: 16px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  font-weight: 600;
  font-size: 0.9rem;
  pointer-events: none;
}

.error {
  color: var(--error);
  font-size: 0.85rem;
  font-weight: 500;
  margin-top: 8px;
  animation: slideIn 0.25s ease;
}

.error:empty {
  display: none;
}

/* Unit toggle with a sliding highlight */
.toggle {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 4px;
}

.toggle-slider {
  position: absolute;
  top: 4px;
  bottom: 4px;
  inset-inline-start: 4px;
  width: calc(50% - 4px);
  border-radius: 9px;
  background: var(--accent);
  box-shadow: 0 2px 8px color-mix(in srgb, var(--accent) 40%, transparent);
  transition: transform 0.3s cubic-bezier(0.3, 0.7, 0.2, 1);
}

.toggle[data-active="lbs"] .toggle-slider,
.toggle[data-active="female"] .toggle-slider {
  transform: translateX(100%);
}

[dir="rtl"] .toggle[data-active="lbs"] .toggle-slider,
[dir="rtl"] .toggle[data-active="female"] .toggle-slider {
  transform: translateX(-100%);
}

/* Lift type dropdown */
.select-wrap {
  position: relative;
}

.select-wrap::after {
  content: "";
  position: absolute;
  inset-inline-end: 18px;
  top: 50%;
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: translateY(-70%) rotate(45deg);
  pointer-events: none;
}

select {
  width: 100%;
  appearance: none;
  -webkit-appearance: none;
  font-family: var(--font-body);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  background: var(--surface-2);
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  padding-block: 14px;
  padding-inline: 16px 44px;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

select:focus {
  border-color: var(--accent-strong);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 25%, transparent);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  line-height: 1.2;
  border-radius: 999px;
  padding: 12px;
  border: 1px solid transparent;
  transition: transform 0.15s ease, background-color 0.2s ease, opacity 0.2s ease;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

.btn-primary {
  background: var(--result-accent);
  color: var(--on-accent);
}

.btn-primary.copied {
  animation: pop 0.4s ease;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--result-text);
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
}

.result-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 22px;
}

/* Very small phones: drop the button icons so the words fit */
@media (max-width: 359px) {
  .result-actions .btn svg {
    display: none;
  }
}

.toggle-btn {
  position: relative;
  font-weight: 700;
  font-size: 1rem;
  color: var(--muted);
  background: transparent;
  border: none;
  border-radius: 9px;
  padding: 11px;
  transition: color 0.25s ease;
}

.toggle-btn.active {
  color: var(--on-accent);
}

/* ---------- Result card ---------- */
.result {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: center;
  background: var(--result-bg);
  color: var(--result-text);
  border-color: transparent;
  padding: 32px 20px;
}

.result::before {
  content: "";
  position: absolute;
  width: 280px;
  height: 280px;
  right: -90px;
  top: -110px;
  border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--result-accent) 35%, transparent), transparent 70%);
  pointer-events: none;
}

.result > * {
  position: relative;
}

.result-label {
  color: var(--result-muted);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

.result {
  container-type: inline-size;
}

.result-value {
  font-family: var(--font-display);
  font-size: clamp(3rem, 18vw, 6.5rem);
  font-size: min(6.5rem, 26cqi); /* scales with the card, so big numbers always fit */
  font-weight: 800;
  line-height: 1;
  color: var(--result-accent);
  margin: 10px 0 8px;
  font-variant-numeric: tabular-nums;
}

.result-value .unit {
  font-size: 0.32em;
  color: var(--result-text);
  margin-inline-start: 6px;
  font-weight: 700;
}

.result-value.pop {
  animation: pop 0.45s cubic-bezier(0.3, 0.7, 0.2, 1);
}

.result-note {
  color: var(--result-muted);
  font-size: 0.92rem;
}

.result-range {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  animation: fadeUp 0.35s ease;
}

.result-range[hidden] {
  display: none;
}

.range-label {
  display: block;
  color: var(--result-muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.range-value {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
}

/* ---------- Strength level ---------- */
.strength-inputs {
  display: grid;
  gap: 20px;
}

.strength-output {
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.strength-message {
  color: var(--muted);
  font-size: 0.95rem;
  text-align: center;
}

#strength-result {
  animation: fadeUp 0.35s ease;
}

.level-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 18px;
}

.level-badge {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  text-transform: uppercase;
  line-height: 1;
  color: var(--accent-strong);
}

.level-badge.pop {
  animation: pop 0.45s cubic-bezier(0.3, 0.7, 0.2, 1);
}

.level-ratio {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--muted);
  background: var(--surface-2);
  border-radius: 999px;
  padding: 6px 12px;
}

.level-bar,
.level-labels {
  direction: ltr;
}

.level-bar {
  position: relative;
  padding: 6px 0;
}

.level-segments {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
}

.level-segments span {
  height: 10px;
  border-radius: 99px;
  background: var(--accent);
}

.level-segments span:nth-child(1) { opacity: 0.2; }
.level-segments span:nth-child(2) { opacity: 0.4; }
.level-segments span:nth-child(3) { opacity: 0.6; }
.level-segments span:nth-child(4) { opacity: 0.8; }

.level-marker {
  position: absolute;
  top: 50%;
  left: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--surface);
  border: 4px solid var(--text);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
  transform: translate(-50%, -50%);
  transition: left 0.6s cubic-bezier(0.3, 0.7, 0.2, 1);
}

.level-labels {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 4px;
  margin-top: 8px;
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--muted);
  text-align: center;
}

.level-labels span.current {
  color: var(--text);
}

/* Short names on small phones so every label fits under its part of the bar */
@media (max-width: 759px) {
  .level-labels .label-full {
    display: none;
  }

  .level-labels > span::after {
    content: attr(data-short);
  }
}

.level-next {
  margin-top: 16px;
  font-size: 0.92rem;
  color: var(--muted);
}

.level-next strong {
  color: var(--text);
}

/* ---------- Formula grid ---------- */
.formula-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

.formula {
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  transition: background-color 0.3s ease;
}

.formula-name {
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 600;
}

.formula-value {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.2;
}

.formula-value small {
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  margin-inline-start: 3px;
}

.updated .formula-value,
.updated td {
  animation: fadeUp 0.35s ease both;
}

/* ---------- Table ---------- */
.table-wrap {
  overflow-x: auto;
  margin: 0 -4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
}

th {
  text-align: start;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0 4px 10px;
}

td {
  padding: 12px 4px;
  border-top: 1px solid var(--border);
  font-weight: 600;
  vertical-align: middle;
}

.num {
  text-align: end;
}

.pct-cell {
  display: flex;
  align-items: center;
  gap: 10px;
}

.pct-bar {
  flex: 0 0 48px;
  height: 6px;
  border-radius: 99px;
  background: var(--surface-2);
  overflow: hidden;
}

.pct-bar span {
  display: block;
  height: 100%;
  background: var(--accent);
  border-radius: inherit;
}

.weight-cell {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
}

.weight-cell small {
  font-family: var(--font-body);
  font-size: 0.78rem;
  color: var(--muted);
  font-weight: 500;
  margin-inline-start: 3px;
}

tbody tr:first-child .weight-cell {
  color: var(--accent-strong);
}

/* ---------- Language switcher ---------- */
.lang-switch {
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  height: 42px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
}

.lang-switch:focus-within {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}

.lang-code {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

/* The real dropdown sits invisibly on top, so phones show their own language picker */
.lang-switch select {
  position: absolute;
  inset: 0;
  width: 100%;
  opacity: 0;
  cursor: pointer;
  font-size: 16px;
}

.guide-note {
  max-width: 68ch;
  margin: 0 auto 24px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
}

.guide-note[hidden] {
  display: none;
}

/* ---------- Guide content ---------- */
html {
  scroll-behavior: smooth;
}

.content {
  padding: 28px 20px;
  font-size: 1.02rem;
  line-height: 1.7;
}

.content > section {
  max-width: 68ch;
  margin: 0 auto;
  scroll-margin-top: 80px; /* keeps headings visible below the sticky header */
}

.content > section + section {
  margin-top: 44px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}

.content h2 {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 6vw, 2.2rem);
  font-weight: 800;
  text-transform: uppercase;
  line-height: 1.1;
  letter-spacing: 0;
  margin-bottom: 14px;
}

.content h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 26px 0 8px;
}

.content p,
.content ul,
.content ol {
  margin-bottom: 14px;
}

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

.content ul,
.content ol {
  padding-left: 1.3em;
}

.content li {
  margin-bottom: 8px;
}

.content li::marker {
  color: var(--accent-strong);
  font-weight: 700;
}

.content a {
  color: var(--accent-strong);
  text-underline-offset: 3px;
}

.content strong {
  font-weight: 650;
}

.formula-box {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.92rem;
  background: var(--surface-2);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 10px 14px;
  overflow-x: auto;
  white-space: nowrap;
}

.tip {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 0.95rem;
}

/* Table of contents */
.toc {
  max-width: 68ch;
  margin: 0 auto 40px;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
}

.toc-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted);
  margin-bottom: 8px;
}

.toc ol {
  margin: 0;
  display: grid;
  gap: 2px;
}

.toc li {
  margin: 0;
}

.toc a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
}

.toc a:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

/* FAQ */
.faq details {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  background: var(--surface);
  transition: border-color 0.2s ease;
}

.faq details[open] {
  border-color: var(--accent-strong);
}

.faq summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
}

.faq summary::after {
  content: "+";
  flex: none;
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--surface-2);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--accent-strong);
  transition: transform 0.25s ease;
}

.faq details[open] summary::after {
  transform: rotate(45deg);
}

.faq details p {
  padding: 0 16px 16px;
  color: var(--muted);
  animation: fadeUp 0.3s ease;
}

@media (min-width: 760px) {
  .content {
    padding: 48px 40px;
  }

  .toc ol {
    grid-template-columns: 1fr 1fr;
    column-gap: 32px;
  }
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  transition: background-color 0.3s ease;
}

.footer-inner {
  max-width: 1000px;
  margin: 0 auto;
  padding: 28px 16px;
  text-align: center;
  display: grid;
  gap: 8px;
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.2rem;
  text-transform: uppercase;
}

.footer-brand span {
  color: var(--muted);
  font-weight: 600;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px 20px;
  margin: 4px 0;
}

.footer-links a {
  color: var(--text);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--accent-strong);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- Info pages (about, privacy, terms, contact) ---------- */
.updated-date {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 10px;
}

.contact-card {
  max-width: 68ch;
  margin: 0 auto;
  text-align: center;
}

.contact-email {
  display: inline-block;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 7vw, 2.4rem);
  font-weight: 700;
  color: var(--accent-strong);
  text-decoration: none;
  word-break: break-all;
  margin: 8px 0 20px;
}

.contact-card .btn-primary {
  background: var(--accent);
  text-decoration: none;
}

.footer-note {
  color: var(--muted);
  font-size: 0.85rem;
  max-width: 520px;
  margin: 0 auto;
}

.footer-copy {
  color: var(--muted);
  font-size: 0.8rem;
  opacity: 0.8;
}

/* ---------- Animations ---------- */
@keyframes pop {
  0% { transform: scale(0.94); opacity: 0.6; }
  60% { transform: scale(1.03); opacity: 1; }
  100% { transform: scale(1); }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: none; }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateY(-3px); }
  to { opacity: 1; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- Larger screens ---------- */
@media (min-width: 760px) {
  .container {
    padding-top: 48px;
    gap: 24px;
  }

  .top-grid {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .card {
    padding: 28px;
  }

  .formula-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
  }

  .strength-inputs {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .level-labels {
    font-size: 0.8rem;
  }

  .pct-bar {
    flex-basis: 90px;
  }
}

/* Full menu row on wide screens */
@media (min-width: 960px) {
  .site-nav {
    position: static;
    display: flex;
    flex-direction: row;
    gap: 2px;
    margin-inline-start: auto;
    margin-inline-end: 12px;
    padding: 0;
    background: none;
    border: none;
    box-shadow: none;
  }

  .site-nav a {
    padding: 8px 12px;
    font-size: 0.95rem;
    white-space: nowrap;
  }

  .menu-toggle {
    display: none;
  }
}

/* Phones: compact header so the logo, language, theme and menu buttons fit on one line */
.logo-text {
  white-space: nowrap;
}

@media (max-width: 480px) {
  .header-inner {
    gap: 8px;
  }

  .logo {
    gap: 8px;
  }

  .logo-text {
    font-size: 1.2rem;
  }

  .header-actions {
    gap: 6px;
  }

  .lang-switch {
    height: 38px;
    padding: 0 10px;
  }

  .theme-toggle,
  .menu-toggle {
    width: 38px;
    height: 38px;
  }
}

@media (max-width: 360px) {
  .logo-text span,
  .lang-switch svg {
    display: none;
  }
}