/* ============================================================
   Natural Elite — style.css
   Theme driven by CSS custom properties updated via main.js
   ============================================================ */

/* ---- Reset -------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
ul { list-style: none; }
a { text-decoration: none; }

/* ---- Custom Properties -------------------------------------- */
:root {
  --bg:           #1e1c1a;
  --accent:       #f0b429;
  --text:         rgba(255, 255, 255, 0.92);
  --text-muted:   rgba(255, 255, 255, 0.45);
  --card-bg:      rgba(255, 255, 255, 0.04);
  --card-border:  rgba(255, 255, 255, 0.08);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

/* ---- Base --------------------------------------------------- */
html { font-size: 16px; }

body {
  font-family: var(--font);
  font-weight: 400;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  /* Background color transitions with worldview shift */
  transition: background-color 0.5s ease;
  /* Future: blur/gradient morphing between worldviews can be layered here */
}

/* ---- Navigation --------------------------------------------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 3rem;
  background: linear-gradient(to bottom, rgba(0,0,0,0.35) 0%, transparent 100%);
}

.nav-logo {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.05em;
  transition: color 0.45s ease;
}

.nav-links {
  display: flex;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.8125rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  transition: color 0.2s ease;
}

.nav-links a:hover { color: var(--text); }

/* ---- Hero --------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 8rem 2rem 4rem;
  text-align: center;
  max-width: 820px;
  margin: 0 auto;
}

/* ---- Worldview Selector ------------------------------------- */
.worldview-selector {
  width: 100%;
  max-width: 460px;
  margin-bottom: 4.5rem;
}

.selector-top {
  height: 1.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.125rem;
}

.selector-label {
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  transition: color 0.45s ease;
}

/* Track — large hit area, thin visual line via ::before */
.slider-track {
  position: relative;
  height: 40px;       /* hit area — easy to click and drag */
  background: transparent;
  cursor: pointer;
  outline: none;
  display: flex;
  align-items: center;
}

/* Visual 1px line */
.slider-track::before {
  content: '';
  position: absolute;
  left: 0; right: 0;
  top: 50%;
  height: 1px;
  background: var(--card-border);
  transform: translateY(-50%);
  transition: background 0.45s ease;
  pointer-events: none;
}

.slider-track:focus-visible::before {
  box-shadow: 0 0 0 2px var(--accent);
}

/* Marker dots */
.slider-marker {
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--card-border);
  pointer-events: none;
  transition: background 0.3s ease;
}

.slider-marker.active {
  background: var(--accent);
  transition: background 0.45s ease;
}

/* Handle */
.slider-handle {
  position: absolute;
  top: 50%;
  left: 0%;
  transform: translate(-50%, -50%);
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--accent);
  pointer-events: none;
  /* Smooth snap between positions */
  transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.45s ease;
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.06);
}

.selector-bottom {
  display: flex;
  justify-content: space-between;
  margin-top: 0.875rem;
}

.axis-label {
  font-size: 0.625rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

/* ---- Hero Content ------------------------------------------- */
.hero-content {
  transition: opacity 0.18s ease;
}

.hero-content.fade-out {
  opacity: 0;
}

.eyebrow {
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.75rem;
  transition: color 0.45s ease;
}

.headline {
  font-size: clamp(2.75rem, 6vw, 4.25rem);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 1.75rem;
}

.body-copy {
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto 2.75rem;
}

.cta {
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--accent);
  transition: color 0.45s ease, opacity 0.18s ease;
}

.cta:hover { opacity: 0.65; }

/* ---- Concept Cards ------------------------------------------ */
.cards-section {
  padding: 0 2rem 7rem;
  max-width: 1200px;
  margin: 0 auto;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--card-border);
  border-radius: 3px;
  overflow: hidden;
  transition: border-color 0.45s ease;
}

/* Dividers between cards */
.card + .card {
  border-left: 1px solid var(--card-border);
  transition: border-color 0.45s ease;
}

/* Top border on second row of cards */
.card:nth-child(n+5) {
  border-top: 1px solid var(--card-border);
}

/* Remove left border on first card of each row */
.card:nth-child(4n+1) {
  border-left: none;
}

.card {
  padding: 2.5rem 2rem;
  background: var(--card-bg);
  transition: background 0.45s ease, opacity 0.18s ease;
}

.card.fade-out { opacity: 0; }

.card-category {
  font-size: 0.5625rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.125rem;
  transition: color 0.45s ease;
}

.card-title {
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: 0.875rem;
}

.card-desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ---- Responsive --------------------------------------------- */
@media (max-width: 900px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Reset desktop border logic, reapply for 2-column */
  .card:nth-child(4n+1) { border-left: 1px solid var(--card-border); }
  .card:nth-child(2n+1) { border-left: none; }
  .card:nth-child(n+5)  { border-top: none; }
  .card:nth-child(n+3)  { border-top: 1px solid var(--card-border); }
}

@media (max-width: 600px) {
  .nav { padding: 1.25rem 1.5rem; }
  .nav-links { gap: 1.75rem; }

  .hero { padding: 7rem 1.5rem 3rem; }

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

  /* Reset all custom borders, use simple top dividers */
  .card + .card {
    border-left: none;
    border-top: 1px solid var(--card-border);
  }
  .card:nth-child(4n+1) { border-left: none; }
  .card:nth-child(2n+1) { border-left: none; }
  .card:nth-child(n+3)  { border-top: 1px solid var(--card-border); }
  .card:nth-child(n+5)  { border-top: 1px solid var(--card-border); }
}