/* =========================================================
   FNF Mod Installer — GitHub Pages
   Material Design 3 · Shared Stylesheet
   ========================================================= */

/* ---------- Custom Properties (MD3 Tokens) ---------- */
:root {
  /* Seed colour: Purple */
  --md-sys-color-primary:             #9C4DCC;
  --md-sys-color-on-primary:          #FFFFFF;
  --md-sys-color-primary-container:   #F1DDFF;
  --md-sys-color-on-primary-container:#2A0052;

  --md-sys-color-secondary:           #7965A0;
  --md-sys-color-on-secondary:        #FFFFFF;
  --md-sys-color-secondary-container: #EBDEFF;
  --md-sys-color-on-secondary-container:#251443;

  --md-sys-color-surface:             #FDF7FF;
  --md-sys-color-surface-variant:     #EFE0F8;
  --md-sys-color-on-surface:          #1D1A22;
  --md-sys-color-on-surface-variant:  #4D4357;
  --md-sys-color-outline:             #7E7389;
  --md-sys-color-outline-variant:     #D0C3DC;

  --md-sys-color-background:          #FDF7FF;
  --md-sys-color-on-background:       #1D1A22;

  --md-sys-color-error:               #B3261E;
  --md-sys-color-on-error:            #FFFFFF;

  /* Elevation (MD3 uses tonal surfaces) */
  --md-elevation-1: 0 1px 2px rgba(0,0,0,.15), 0 1px 3px 1px rgba(0,0,0,.10);
  --md-elevation-2: 0 1px 2px rgba(0,0,0,.20), 0 2px 6px 2px rgba(0,0,0,.15);
  --md-elevation-3: 0 4px 8px 3px rgba(0,0,0,.15), 0 1px 3px rgba(0,0,0,.20);

  /* Shape */
  --shape-corner-extra-small: 4px;
  --shape-corner-small:       8px;
  --shape-corner-medium:      12px;
  --shape-corner-large:       16px;
  --shape-corner-extra-large: 28px;
  --shape-corner-full:        9999px;

  /* Typescale */
  --font-display-large:  clamp(3rem, 6vw, 3.5625rem);
  --font-display-medium: clamp(2.25rem, 4.5vw, 2.8125rem);
  --font-display-small:  clamp(1.75rem, 3.5vw, 2.25rem);
  --font-headline-large: clamp(1.5rem, 3vw, 2rem);
  --font-headline-medium:clamp(1.25rem, 2.5vw, 1.75rem);
  --font-headline-small: clamp(1.125rem, 2.2vw, 1.5rem);
  --font-title-large:    1.375rem;
  --font-title-medium:   1rem;
  --font-body-large:     1rem;
  --font-body-medium:    0.875rem;
  --font-label-large:    0.875rem;
  --font-label-medium:   0.75rem;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Roboto', sans-serif;
  background: var(--md-sys-color-background);
  color: var(--md-sys-color-on-background);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img { max-width: 100%; display: block; }
a   { color: var(--md-sys-color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Top App Bar ---------- */
.top-app-bar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--md-sys-color-surface);
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  box-shadow: var(--md-elevation-1);
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.top-app-bar__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: var(--font-title-large);
  font-weight: 600;
  color: var(--md-sys-color-on-surface);
  text-decoration: none;
}

.top-app-bar__brand:hover { text-decoration: none; }

.top-app-bar__brand img {
  width: 40px;
  height: 40px;
  border-radius: var(--shape-corner-small);
}

.top-app-bar__brand .brand-emoji {
  font-size: 2rem;
  line-height: 1;
}

.top-app-bar__nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 16px;
  border-radius: var(--shape-corner-full);
  font-size: var(--font-label-large);
  font-weight: 500;
  color: var(--md-sys-color-on-surface-variant);
  transition: background 0.2s, color 0.2s;
}

.nav-link:hover {
  background: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface);
  text-decoration: none;
}

.nav-link.active {
  color: var(--md-sys-color-primary);
  background: var(--md-sys-color-primary-container);
}

/* Hamburger for mobile */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--shape-corner-full);
  color: var(--md-sys-color-on-surface);
  font-size: 1.5rem;
  transition: background 0.2s;
}
.nav-toggle:hover { background: var(--md-sys-color-surface-variant); }

@media (max-width: 640px) {
  .nav-toggle { display: flex; align-items: center; }
  .top-app-bar__nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--md-sys-color-surface);
    padding: 8px 16px 16px;
    flex-direction: column;
    align-items: flex-start;
    border-bottom: 1px solid var(--md-sys-color-outline-variant);
    box-shadow: var(--md-elevation-2);
  }
  .top-app-bar__nav.open { display: flex; }
  .nav-link { width: 100%; padding: 12px 16px; }
}

/* ---------- Main Content ---------- */
main { flex: 1; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: var(--shape-corner-full);
  font-size: var(--font-label-large);
  font-weight: 600;
  letter-spacing: 0.03em;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: box-shadow 0.2s, opacity 0.2s, background 0.2s;
}

.btn-filled {
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  box-shadow: var(--md-elevation-1);
}
.btn-filled:hover {
  box-shadow: var(--md-elevation-2);
  opacity: 0.92;
  text-decoration: none;
}

.btn-tonal {
  background: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}
.btn-tonal:hover {
  box-shadow: var(--md-elevation-1);
  text-decoration: none;
}

.btn-outlined {
  background: transparent;
  color: var(--md-sys-color-primary);
  border: 1px solid var(--md-sys-color-outline);
}
.btn-outlined:hover {
  background: var(--md-sys-color-primary-container);
  text-decoration: none;
}

/* ---------- Cards ---------- */
.card {
  background: var(--md-sys-color-surface);
  border-radius: var(--shape-corner-medium);
  padding: 24px;
  box-shadow: var(--md-elevation-1);
  transition: box-shadow 0.2s;
}
.card:hover { box-shadow: var(--md-elevation-2); }

.card-elevated {
  background: var(--md-sys-color-surface);
  box-shadow: var(--md-elevation-2);
}

.card-filled {
  background: var(--md-sys-color-surface-variant);
  box-shadow: none;
}

/* ---------- Section Layout ---------- */
.section {
  padding: 80px 24px;
}

.section--alt {
  background: var(--md-sys-color-surface-variant);
}

.container {
  max-width: 1100px;
  margin: 0 auto;
}

.container--narrow {
  max-width: 760px;
  margin: 0 auto;
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(
    145deg,
    #2A0052 0%,
    #4A0080 40%,
    #7B1FA2 75%,
    #9C4DCC 100%
  );
  color: #fff;
  text-align: center;
  padding: 100px 24px 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero__logo {
  width: 96px;
  height: 96px;
  margin: 0 auto 24px;
  border-radius: var(--shape-corner-large);
  background: rgba(255,255,255,0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
  backdrop-filter: blur(4px);
  border: 2px solid rgba(255,255,255,0.25);
  position: relative;
}

.hero__eyebrow {
  font-size: var(--font-label-large);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.8;
  margin-bottom: 12px;
  position: relative;
}

.hero__title {
  font-size: var(--font-display-medium);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 20px;
  position: relative;
}

.hero__subtitle {
  font-size: var(--font-headline-small);
  font-weight: 400;
  opacity: 0.9;
  max-width: 560px;
  margin: 0 auto 40px;
  position: relative;
}

.hero__actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  position: relative;
}

/* ---------- Feature Grid ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 48px;
}

.feature-card {
  background: var(--md-sys-color-surface);
  border-radius: var(--shape-corner-large);
  padding: 28px 24px;
  box-shadow: var(--md-elevation-1);
  transition: box-shadow 0.25s, transform 0.25s;
  border: 1px solid var(--md-sys-color-outline-variant);
}

.feature-card:hover {
  box-shadow: var(--md-elevation-3);
  transform: translateY(-2px);
}

.feature-card__icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
  display: block;
}

.feature-card__title {
  font-size: var(--font-title-large);
  font-weight: 600;
  color: var(--md-sys-color-on-surface);
  margin-bottom: 8px;
}

.feature-card__body {
  font-size: var(--font-body-large);
  color: var(--md-sys-color-on-surface-variant);
  line-height: 1.6;
}

/* ---------- Engine chips ---------- */
.engines-section { text-align: center; }

.engines-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 32px;
}

.engine-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: var(--shape-corner-full);
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  font-weight: 600;
  font-size: var(--font-label-large);
  border: 1px solid var(--md-sys-color-outline-variant);
  transition: background 0.2s, box-shadow 0.2s;
}

.engine-chip:hover {
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  box-shadow: var(--md-elevation-1);
}

/* ---------- Section headings ---------- */
.section-label {
  font-size: var(--font-label-large);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--md-sys-color-primary);
  font-weight: 600;
  margin-bottom: 8px;
}

.section-title {
  font-size: var(--font-headline-large);
  font-weight: 700;
  color: var(--md-sys-color-on-surface);
  margin-bottom: 16px;
  line-height: 1.25;
}

.section-body {
  font-size: var(--font-body-large);
  color: var(--md-sys-color-on-surface-variant);
  max-width: 620px;
}

/* ---------- Step List ---------- */
.step-list {
  list-style: none;
  counter-reset: step;
  margin-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.step-list li {
  counter-increment: step;
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.step-list li::before {
  content: counter(step);
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: var(--shape-corner-full);
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--font-title-medium);
}

.step-list li > div { flex: 1; }

.step-title {
  font-size: var(--font-title-medium);
  font-weight: 600;
  color: var(--md-sys-color-on-surface);
}

.step-body {
  font-size: var(--font-body-medium);
  color: var(--md-sys-color-on-surface-variant);
  margin-top: 4px;
}

/* ---------- Download Banner ---------- */
.download-banner {
  background: linear-gradient(135deg, #4A0080, #9C4DCC);
  color: #fff;
  text-align: center;
  padding: 72px 24px;
}

.download-banner__title {
  font-size: var(--font-headline-large);
  font-weight: 700;
  margin-bottom: 12px;
}

.download-banner__sub {
  font-size: var(--font-body-large);
  opacity: 0.88;
  margin-bottom: 36px;
}

.btn-on-dark {
  background: #fff;
  color: #4A0080;
  padding: 14px 32px;
  font-size: 1rem;
  box-shadow: 0 4px 12px rgba(0,0,0,.25);
}
.btn-on-dark:hover {
  box-shadow: 0 6px 18px rgba(0,0,0,.35);
  text-decoration: none;
  opacity: 0.95;
}

/* ---------- Legal Pages ---------- */
.page-hero {
  background: linear-gradient(145deg, #2A0052, #7B1FA2);
  color: #fff;
  padding: 72px 24px 56px;
  text-align: center;
}

.page-hero__title {
  font-size: var(--font-display-small);
  font-weight: 700;
  margin-bottom: 8px;
}

.page-hero__subtitle {
  font-size: var(--font-body-large);
  opacity: 0.8;
}

.legal-content {
  padding: 56px 24px 80px;
}

.legal-content .container--narrow { }

.legal-article {
  background: var(--md-sys-color-surface);
  border-radius: var(--shape-corner-large);
  padding: 40px 48px;
  box-shadow: var(--md-elevation-1);
  border: 1px solid var(--md-sys-color-outline-variant);
}

@media (max-width: 640px) {
  .legal-article { padding: 24px 20px; }
}

.legal-article h2 {
  font-size: var(--font-headline-medium);
  font-weight: 700;
  color: var(--md-sys-color-on-surface);
  margin: 40px 0 12px;
  padding-top: 8px;
  border-top: 1px solid var(--md-sys-color-outline-variant);
}

.legal-article h2:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.legal-article h3 {
  font-size: var(--font-title-large);
  font-weight: 600;
  color: var(--md-sys-color-primary);
  margin: 24px 0 8px;
}

.legal-article p {
  font-size: var(--font-body-large);
  color: var(--md-sys-color-on-surface-variant);
  line-height: 1.7;
  margin-bottom: 16px;
}

.legal-article ul, .legal-article ol {
  padding-left: 24px;
  margin-bottom: 16px;
}

.legal-article li {
  font-size: var(--font-body-large);
  color: var(--md-sys-color-on-surface-variant);
  line-height: 1.7;
  margin-bottom: 6px;
}

.legal-article strong {
  color: var(--md-sys-color-on-surface);
  font-weight: 600;
}

.last-updated-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--font-body-medium);
  color: var(--md-sys-color-on-surface-variant);
  background: var(--md-sys-color-surface-variant);
  padding: 6px 14px;
  border-radius: var(--shape-corner-full);
  margin-bottom: 32px;
}

/* ---------- Footer ---------- */
footer {
  background: #1D1A22;
  color: #E6DFF0;
  padding: 48px 24px 32px;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px 64px;
  align-items: start;
}

@media (max-width: 640px) {
  .footer-inner { grid-template-columns: 1fr; }
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  font-size: var(--font-title-large);
  font-weight: 600;
  color: #fff;
}

.footer-desc {
  font-size: var(--font-body-medium);
  color: #B0A8C0;
  max-width: 380px;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: #B0A8C0;
  font-size: var(--font-body-medium);
  transition: color 0.2s;
}

.footer-links a:hover { color: #fff; text-decoration: none; }

.footer-divider {
  max-width: 1100px;
  margin: 32px auto 20px;
  border: none;
  border-top: 1px solid #2D2834;
}

.footer-copy {
  max-width: 1100px;
  margin: 0 auto;
  font-size: var(--font-body-medium);
  color: #7B7088;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- 404 Page ---------- */
.error-page {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 80px 24px;
  background: var(--md-sys-color-background);
}

.error-code {
  font-size: clamp(6rem, 20vw, 10rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: var(--font-headline-medium);
  font-weight: 700;
  color: var(--md-sys-color-on-surface);
  margin-bottom: 12px;
}

.error-body {
  font-size: var(--font-body-large);
  color: var(--md-sys-color-on-surface-variant);
  max-width: 480px;
  margin: 0 auto 36px;
}

/* ---------- Divider ---------- */
.divider {
  border: none;
  border-top: 1px solid var(--md-sys-color-outline-variant);
  margin: 0;
}

/* ---------- Chip strip (badges) ---------- */
.badge-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  border-radius: var(--shape-corner-full);
  font-size: var(--font-label-medium);
  font-weight: 500;
  background: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}

/* ---------- Ripple-like focus ring (accessibility) ---------- */
:focus-visible {
  outline: 3px solid var(--md-sys-color-primary);
  outline-offset: 2px;
}

/* ---------- Scroll-reveal utility ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
.reveal.visible {
  opacity: 1;
  transform: none;
}