/* ═══════════════════════════════════════════════
   Arcline Project — Fedora-inspired Stylesheet
   ═══════════════════════════════════════════════ */

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

/* ── Design Tokens ── */
/* Dark mode is the default */
:root {
  /* Colors */
  --color-bg:            #0d1117;
  --color-bg-alt:        #161b22;
  --color-bg-card:       #161b22;
  --color-bg-card-hover: #1c2333;
  --color-bg-dark:       #0b0c0e;

  --color-border:        #30363d;
  --color-border-hover:  #484f58;
  --color-border-light:  #21262d;

  --color-text:          #e6edf3;
  --color-text-soft:     #8b949e;
  --color-text-faint:    #6e7681;
  --color-text-inverse:  #e6edf3;

  --color-accent:        #0acf97;
  --color-accent-dim:    hsl(162 88% 43%);
  --color-accent-bg:     hsla(162 88% 43% / 0.10);
  --color-accent-border: hsla(162 88% 43% / 0.22);

  --color-cta-text:      #0b0c0e;

  --color-nav-bg:        rgba(13, 17, 23, 0.92);
  --color-hero-gradient: linear-gradient(180deg, #0d1117 0%, #161b22 50%, #0d1117 100%);

  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "SF Mono", "Cascadia Code", monospace;

  /* Spacing */
  --w-main:      1120px;
  --w-narrow:    720px;
  --pad-section: 80px;
  --pad-card:    28px;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;

  /* Shadows */
  --shadow-card:  0 1px 3px rgba(0,0,0,0.24), 0 1px 2px rgba(0,0,0,0.16);
  --shadow-hover: 0 4px 14px rgba(0,0,0,0.32), 0 2px 4px rgba(0,0,0,0.16);
  --shadow-nav:   0 1px 3px rgba(0,0,0,0.24);

  /* Transitions */
  --ease: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light mode overrides */
[data-theme="light"] {
  --color-bg:            #ffffff;
  --color-bg-alt:        #f5f6f8;
  --color-bg-card:       #ffffff;
  --color-bg-card-hover: #f8f9fb;

  --color-border:        #e2e4e8;
  --color-border-hover:  #c8cad0;
  --color-border-light:  #eeeff2;

  --color-text:          #1a1c22;
  --color-text-soft:     #4a4e58;
  --color-text-faint:    #7c808a;
  --color-text-inverse:  #ffffff;

  --color-accent:        #0acf97;
  --color-accent-dim:    hsl(162 88% 33%);
  --color-accent-bg:     hsla(162 88% 43% / 0.07);
  --color-accent-border: hsla(162 88% 43% / 0.18);

  --color-cta-text:      #0d1117;

  --color-nav-bg:        rgba(255, 255, 255, 0.92);
  --color-hero-gradient: linear-gradient(180deg, #f8f9fb 0%, #ffffff 100%);

  --shadow-card:  0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-hover: 0 4px 14px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-nav:   0 1px 3px rgba(0,0,0,0.06);
}

/* ── Base ── */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ── Skip to Content ── */
.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 1000;
  padding: 10px 18px;
  background: var(--color-accent);
  color: var(--color-cta-text);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top 0.2s;
}

.skip-link:focus {
  top: 8px;
}

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

.nav-inner {
  max-width: var(--w-main);
  margin: 0 auto;
  padding: 0 28px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 650;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.logo-icon {
  flex-shrink: 0;
  border-radius: 4px;
}

.nav nav {
  display: flex;
  gap: 4px;
  align-items: center;
}

.nav nav a {
  color: var(--color-text-soft);
  text-decoration: none;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--ease), background var(--ease);
}

.nav nav a:hover,
.nav nav a:focus-visible {
  color: var(--color-text);
  background: var(--color-bg-alt);
}

.nav-cta {
  background: var(--color-accent) !important;
  color: var(--color-cta-text) !important;
  font-weight: 600 !important;
  margin-left: 8px;
}

.nav-cta:hover {
  background: var(--color-accent-dim) !important;
  color: var(--color-cta-text) !important;
}

/* ── Theme Toggle ── */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-text-soft);
  cursor: pointer;
  transition: color var(--ease), background var(--ease);
  margin-left: 8px;
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-bg-alt);
}

/* Show the sun icon (toggle to light) in dark mode, moon icon (toggle to dark) in light mode */
.theme-icon-dark  { display: none; }
.theme-icon-light { display: block; }

[data-theme="light"] .theme-icon-dark  { display: block; }
[data-theme="light"] .theme-icon-light { display: none; }

/* ── Hero ── */
.hero {
  padding: 90px 28px 70px;
  text-align: center;
  background: var(--color-hero-gradient);
  border-bottom: 1px solid var(--color-border-light);
}

.hero-inner {
  max-width: var(--w-narrow);
  margin: 0 auto;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 750;
  letter-spacing: -0.03em;
  line-height: 1.12;
  margin-bottom: 20px;
  color: var(--color-text);
}

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

.tagline {
  font-size: 1.1rem;
  color: var(--color-text-soft);
  margin-bottom: 36px;
  line-height: 1.7;
  max-width: 530px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.cta {
  display: inline-flex;
  align-items: center;
  background: var(--color-accent);
  color: var(--color-cta-text);
  padding: 14px 32px;
  font-size: 0.95rem;
  font-weight: 620;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--ease), transform var(--ease), box-shadow var(--ease);
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
  box-shadow: 0 2px 8px hsla(162 88% 43% / 0.25);
}

.cta:hover {
  background: var(--color-accent-dim);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px hsla(162 88% 43% / 0.35);
}

.cta-secondary {
  display: inline-flex;
  align-items: center;
  color: var(--color-text-soft);
  padding: 14px 32px;
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--ease), color var(--ease), background var(--ease);
}

.cta-secondary:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
  background: var(--color-bg-alt);
}

/* ── Sections ── */
.section {
  padding: var(--pad-section) 28px;
  text-align: center;
}

.section-alt {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border-light);
  border-bottom: 1px solid var(--color-border-light);
}

.section-inner {
  max-width: var(--w-main);
  margin: 0 auto;
}

.section-label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
  padding: 5px 14px;
  background: var(--color-accent-bg);
  border-radius: 20px;
}

.section-inner h2 {
  font-size: clamp(1.6rem, 3.2vw, 2.2rem);
  font-weight: 720;
  margin-bottom: 18px;
  margin-left: auto;
  margin-right: auto;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--color-text);
  max-width: 640px;
}

.section-desc {
  color: var(--color-text-soft);
  font-size: 1.02rem;
  max-width: 600px;
  margin-bottom: 48px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.7;
}

/* ── Edition Cards ── */
.editions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.edition-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px 28px;
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease), transform var(--ease);
  text-align: center;
}

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

.edition-icon {
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-bg);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
  color: var(--color-accent);
}

.edition-card h3 {
  font-size: 1.12rem;
  font-weight: 680;
  margin-bottom: 10px;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.edition-card p {
  color: var(--color-text-soft);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 22px;
  flex: 1;
}

.edition-card .card-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
}

.card-btn {
  display: inline-flex;
  align-items: center;
  padding: 9px 22px;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--ease), color var(--ease), border-color var(--ease);
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
}

.card-btn-primary {
  background: var(--color-accent);
  color: var(--color-cta-text);
}

.card-btn-primary:hover {
  background: var(--color-accent-dim);
}

.card-btn-secondary {
  color: var(--color-text-soft);
  border: 1.5px solid var(--color-border);
  background: transparent;
}

.card-btn-secondary:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
  background: var(--color-bg-alt);
}

/* ── Feature Grid ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 16px;
}

.feature-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-decoration: none;
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease);
  text-align: left;
}

.feature-card:hover {
  border-color: var(--color-accent-border);
  box-shadow: var(--shadow-hover);
}

.feature-card h4 {
  font-size: 0.94rem;
  font-weight: 650;
  color: var(--color-text);
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.feature-card p {
  font-size: 0.84rem;
  color: var(--color-text-soft);
  line-height: 1.55;
}

/* ── Principles Grid ── */
.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 16px;
}

.principle {
  display: flex;
  gap: 18px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--pad-card);
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease);
  text-align: left;
}

.principle:hover {
  border-color: var(--color-accent-border);
  box-shadow: var(--shadow-hover);
}

.principle-icon {
  flex-shrink: 0;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-bg);
  color: var(--color-accent);
  border-radius: var(--radius-sm);
  margin-top: 2px;
}

.principle h3 {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  font-weight: 640;
  margin-bottom: 5px;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.principle p {
  color: var(--color-text-soft);
  font-size: 0.86rem;
  line-height: 1.6;
}

/* ── Stack Grid ── */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.stack-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease);
  text-align: left;
}

.stack-card:hover {
  border-color: var(--color-accent-border);
  box-shadow: var(--shadow-hover);
}

.stack-header {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 650;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 22px 24px 10px 24px;
  color: var(--color-accent);
}

.stack-card ul {
  list-style: none;
  padding: 0 24px 24px 24px;
  margin: 0;
}

.stack-card li {
  position: relative;
  padding: 7px 0 7px 18px;
  color: var(--color-text-soft);
  font-size: 0.84rem;
  line-height: 1.5;
}

.stack-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 13px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0.5;
}

/* Edition Teaser */
.edition-teaser {
  margin-top: 24px;
  padding: 20px 28px;
  border: 1px dashed var(--color-accent-border);
  border-radius: var(--radius-md);
  background: var(--color-accent-bg);
  text-align: left;
}

.edition-teaser-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 600;
  color: var(--color-accent-dim);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.edition-teaser p {
  color: var(--color-text-soft);
  font-size: 0.9rem;
  line-height: 1.7;
  max-width: 700px;
}

.edition-teaser strong {
  color: var(--color-text);
  font-weight: 660;
}

/* ── Tool Grid ── */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 12px;
}

.tool {
  display: flex;
  flex-direction: column;
  gap: 6px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  text-align: left;
  transition: border-color var(--ease), box-shadow var(--ease);
}

.tool:hover {
  border-color: var(--color-accent-border);
  box-shadow: var(--shadow-card);
}

.tool code {
  font-family: var(--font-mono);
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--color-accent-dim);
  letter-spacing: -0.01em;
}

.tool span {
  color: var(--color-text-soft);
  font-size: 0.83rem;
  line-height: 1.55;
}

/* ── Compare Grid ── */
.compare-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 14px;
}

.compare-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  text-align: left;
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease);
}

.compare-card:hover {
  border-color: var(--color-accent-border);
  box-shadow: var(--shadow-hover);
}

.compare-highlight {
  border-color: var(--color-accent-border);
  border-width: 2px;
  background: linear-gradient(160deg, var(--color-bg-card) 0%, var(--color-accent-bg) 100%);
}

.compare-label {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 630;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 10px;
  color: var(--color-text-faint);
}

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

.compare-desc {
  color: var(--color-text-soft);
  font-size: 0.89rem;
  line-height: 1.6;
}

/* ── Contribute Grid ── */
.contribute-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.contribute-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  color: var(--color-text);
  text-decoration: none;
  box-shadow: var(--shadow-card);
  transition: border-color var(--ease), box-shadow var(--ease), transform var(--ease);
  text-align: left;
  position: relative;
}

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

.contribute-card::after {
  content: " →";
  position: absolute;
  right: 24px;
  top: 28px;
  font-family: var(--font-mono);
  color: var(--color-accent);
  opacity: 0;
  transform: translateX(-8px);
  transition: opacity var(--ease), transform var(--ease);
}

.contribute-card:hover::after {
  opacity: 1;
  transform: translateX(0);
}

.contribute-card span {
  font-size: 0.98rem;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.contribute-card small {
  color: var(--color-text-soft);
  font-size: 0.84rem;
  line-height: 1.5;
}

.contribute-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-bg);
  color: var(--color-accent);
  border-radius: var(--radius-sm);
  margin-bottom: 2px;
}

/* ── Inline Link ── */
.inline-link {
  color: var(--color-accent-dim);
  text-decoration: none;
  border-bottom: 1.5px solid var(--color-accent-border);
  padding-bottom: 1px;
  transition: border-color var(--ease), color var(--ease);
}

.inline-link:hover {
  border-bottom-color: var(--color-accent);
  color: var(--color-accent-dim);
}

/* ── Sponsor ── */
.sponsor-section .section-inner {
  text-align: left;
}

.sponsor-content {
  display: flex;
  flex-direction: column;
  gap: 22px;
  max-width: 640px;
}

.sponsor-desc {
  color: var(--color-text-soft);
  font-size: 0.95rem;
  line-height: 1.7;
}

.sponsor-desc strong {
  color: var(--color-text);
  font-weight: 660;
}

.sponsor-tagline {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-faint);
  padding: 8px 0;
  border-left: 3px solid var(--color-accent);
  padding-left: 14px;
}

/* ── Waitlist Form ── */
.waitlist-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 480px;
  margin: 0 auto;
}

.edition-checkboxes {
  border: none;
  padding: 0;
  display: flex;
  gap: 24px;
  justify-content: center;
}

.edition-checkboxes legend {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-soft);
  margin-bottom: 10px;
  padding: 0;
  float: left;
  width: 100%;
  text-align: center;
}

.edition-checkbox {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--color-text-soft);
  user-select: none;
  transition: color var(--ease);
}

.edition-checkbox:hover {
  color: var(--color-text);
}

.edition-checkbox input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-bg);
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
  transition: border-color var(--ease), background var(--ease);
}

.edition-checkbox input[type="checkbox"]:checked {
  border-color: var(--color-accent);
  background: var(--color-accent);
}

.edition-checkbox input[type="checkbox"]:checked::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 2px;
  width: 5px;
  height: 10px;
  border: solid var(--color-cta-text);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.input {
  padding: 13px 18px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 0.92rem;
  outline: none;
  transition: border-color var(--ease), box-shadow var(--ease);
  font-family: var(--font-mono);
}

.input::placeholder {
  color: var(--color-text-faint);
  font-family: var(--font-mono);
}

.input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-bg);
}

.btn {
  padding: 13px 30px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--color-accent);
  color: var(--color-cta-text);
  font-size: 0.92rem;
  font-weight: 620;
  cursor: pointer;
  transition: background var(--ease), transform var(--ease);
  font-family: var(--font-mono);
  letter-spacing: -0.01em;
}

.btn:hover {
  background: var(--color-accent-dim);
  transform: translateY(-1px);
}

.confirmation {
  margin-top: 18px;
  padding: 14px 22px;
  color: var(--color-accent-dim);
  background: var(--color-accent-bg);
  border: 1px solid var(--color-accent-border);
  border-radius: var(--radius-sm);
  font-weight: 520;
  font-size: 0.9rem;
  display: inline-block;
  font-family: var(--font-mono);
}

.waitlist-note {
  margin-top: 20px;
  font-size: 0.82rem;
  color: var(--color-text-faint);
}

/* ── Footer ── */
.footer {
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
  padding: 56px 28px 32px;
}

.footer-grid {
  max-width: var(--w-main);
  margin: 0 auto 36px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 650;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.footer-col p {
  color: hsla(0 0% 100% / 0.6);
  font-size: 0.88rem;
  line-height: 1.7;
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  color: hsla(0 0% 100% / 0.55);
  text-decoration: none;
  font-size: 0.87rem;
  transition: color var(--ease);
}

.footer-col a:hover {
  color: var(--color-accent);
}

.footer-logo {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 650;
  color: #ffffff;
  text-decoration: none;
  letter-spacing: -0.01em;
  display: inline-block;
  margin-bottom: 10px;
}

.footer-bottom {
  max-width: var(--w-main);
  margin: 0 auto;
  padding-top: 24px;
  border-top: 1px solid hsla(0 0% 100% / 0.08);
  text-align: center;
}

.footer-bottom p {
  font-family: var(--font-mono);
  color: hsla(0 0% 100% / 0.3);
  font-size: 0.76rem;
}

/* ── Responsive ── */
@media (max-width: 920px) {
  .stack-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .footer-col:first-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  :root {
    --pad-section: 56px;
  }

  .hero {
    padding: 60px 22px 50px;
  }

  .section {
    padding: var(--pad-section) 22px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .cta,
  .cta-secondary {
    justify-content: center;
    text-align: center;
  }

  .nav nav {
    gap: 0;
  }

  .nav nav a {
    padding: 6px 10px;
    font-size: 0.8rem;
  }

  .principles-grid {
    grid-template-columns: 1fr;
  }

  .tool-grid {
    grid-template-columns: 1fr;
  }

  .editions-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 580px) {
  .hero {
    padding: 44px 18px 36px;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .section {
    padding: 42px 18px;
  }

  .section-inner h2 {
    font-size: 1.35rem;
  }

  .nav-inner {
    padding: 0 14px;
  }

  .nav nav a {
    padding: 6px 7px;
    font-size: 0.74rem;
  }

  .input {
    min-width: 100%;
  }

  .btn {
    width: 100%;
  }

  .stack-grid {
    grid-template-columns: 1fr;
  }

  .compare-grid {
    grid-template-columns: 1fr;
  }

  .contribute-grid {
    grid-template-columns: 1fr;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}