@import url('https://fonts.googleapis.com/css2?family=Exo+2:ital,wght@0,300;0,400;0,700;1,300&family=Inter:wght@300;400;500;600&display=swap');

:root {
  --bg:     #060612;
  --bg2:    #0c0c20;
  --card:   #0f0f24;
  --border: #1c1c38;
  --purple: #a855f7;
  --cyan:   #22d3ee;
  --pink:   #ec4899;
  --green:  #4ade80;
  --text:   #f0f0ff;
  --text2:  #8080b0;
  --muted:  #2a2a50;
}

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

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

/* ── HEADER ──────────────────────── */
.fr-header {
  position: relative;
  min-height: 380px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}

.fr-canvas-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.65;
}

.fr-header-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 40px 24px;
  max-width: 800px;
}

.fr-dept { font-size: 0.7rem; letter-spacing: 0.25em; text-transform: uppercase; color: var(--cyan); margin-bottom: 16px; font-weight: 600; }

.fr-title {
  font-family: 'Exo 2', sans-serif;
  font-size: clamp(3rem, 10vw, 6rem);
  font-weight: 700;
  color: var(--text);
  text-shadow: 0 0 40px rgba(168,85,247,.6), 0 0 80px rgba(34,211,238,.3);
  letter-spacing: -0.02em;
  line-height: 1;
}

.fr-tagline { margin-top: 16px; color: rgba(240,240,255,.7); font-size: 0.95rem; font-style: italic; }

.fr-header-stat-row { display: flex; justify-content: center; gap: 32px; margin-top: 24px; }
.fr-stat { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.fr-stat-n { font-family: 'Exo 2', monospace; font-size: 1.4rem; font-weight: 700; color: var(--purple); }
.fr-stat span:last-child { font-size: 0.72rem; color: var(--text2); }

/* ── NAV ─────────────────────────── */
.fr-nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(6,6,18,.9); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  display: flex; flex-wrap: wrap; justify-content: center;
}

.fr-nav-a {
  padding: 12px 16px; font-size: 0.78rem; font-weight: 500;
  text-decoration: none; color: var(--text2);
  border-bottom: 2px solid transparent; transition: all 0.2s; white-space: nowrap;
}
.fr-nav-a:hover { color: var(--purple); border-color: var(--purple); }
.fr-nav-a.active { color: var(--purple); border-color: var(--purple); }

/* ── MAIN ────────────────────────── */
.fr-main { max-width: 1000px; margin: 0 auto; padding: 48px 24px 80px; display: flex; flex-direction: column; gap: 52px; }

/* ── SECTION ─────────────────────── */
.fr-section { opacity: 0; transform: translateY(28px); transition: opacity .5s, transform .5s; }
.fr-section.visible { opacity: 1; transform: translateY(0); }

.fr-sec-head {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 22px; border-radius: 10px 10px 0 0;
  border-left: 4px solid transparent;
}
.fr-sec-head.purple { background: rgba(168,85,247,.1); border-color: var(--purple); }
.fr-sec-head.cyan   { background: rgba(34,211,238,.08); border-color: var(--cyan); }
.fr-sec-head.pink   { background: rgba(236,72,153,.08); border-color: var(--pink); }

.fr-sec-icon { font-size: 1.3rem; }
.fr-sec-head h2 { font-family: 'Exo 2', sans-serif; font-size: 1.3rem; font-weight: 700; color: var(--text); }

.fr-sec-body {
  background: var(--card); border: 1px solid var(--border);
  border-top: none; border-radius: 0 0 10px 10px; padding: 28px;
}

.fr-sec-body p { color: var(--text2); line-height: 1.82; font-size: 0.95rem; margin-bottom: 18px; }
.fr-sec-body p:last-child { margin-bottom: 0; }
.fr-sec-body strong { color: var(--text); }

/* ── DEF CARDS ───────────────────── */
.fr-def-cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; margin-top: 18px; }
.fr-def-c { background: rgba(168,85,247,.06); border: 1px solid rgba(168,85,247,.15); border-radius: 8px; padding: 16px; }
.fr-def-c h4 { font-size: 0.85rem; font-weight: 700; color: var(--purple); margin-bottom: 8px; }
.fr-def-c p  { font-size: 0.83rem; color: var(--text2); margin: 0; line-height: 1.7; }

/* ── TIMELINE ────────────────────── */
.fr-timeline { display: flex; flex-direction: column; gap: 12px; }
.fr-tl { display: flex; gap: 16px; align-items: flex-start; }
.fr-tl-y { font-family: 'Exo 2', monospace; font-size: 0.75rem; font-weight: 700; color: var(--cyan); width: 50px; flex-shrink: 0; padding-top: 3px; }
.fr-tl-c { flex: 1; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; padding: 12px 16px; font-size: 0.87rem; color: var(--text2); line-height: 1.7; }
.fr-tl-c strong { color: var(--text); }
.fr-tl-c em { color: var(--pink); font-style: italic; }

/* ── AUTOSIM GRID ────────────────── */
.fr-autosim-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; margin-bottom: 22px; }
.fr-as-card { background: rgba(236,72,153,.06); border: 1px solid rgba(236,72,153,.15); border-radius: 8px; padding: 16px; }
.fr-as-card h4 { font-size: 0.85rem; font-weight: 700; color: var(--pink); margin-bottom: 8px; }
.fr-as-card p  { font-size: 0.83rem; color: var(--text2); margin: 0; line-height: 1.7; }

.fr-examples-row { display: flex; gap: 16px; margin-top: 18px; }
.fr-ex { flex: 1; text-align: center; }
.fr-ex-art { height: 120px; background: var(--bg2); border: 1px solid var(--border); border-radius: 8px; display: flex; align-items: center; justify-content: center; margin-bottom: 8px; overflow: hidden; }
.fr-ex p { font-size: 0.78rem; color: var(--text2); }

/* ── DIMENSION ───────────────────── */
.fr-dim-formula {
  text-align: center; background: rgba(168,85,247,.08);
  border: 1px solid rgba(168,85,247,.2); border-radius: 10px; padding: 20px; margin: 18px 0;
}
.fr-dim-f-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--purple); margin-bottom: 8px; }
.fr-dim-f-eq { font-family: 'Exo 2', monospace; font-size: 1.5rem; font-weight: 700; color: var(--text); }
.fr-dim-f-exp { font-size: 0.78rem; color: var(--text2); margin-top: 6px; }

.fr-dim-table { border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.fr-dim-th { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; padding: 9px 14px; background: rgba(255,255,255,.04); font-size: 0.72rem; font-weight: 700; text-transform: uppercase; color: var(--text2); letter-spacing: 0.08em; }
.fr-dim-tr { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; padding: 9px 14px; border-top: 1px solid var(--border); font-size: 0.87rem; color: var(--text2); }
.fr-dim-tr:hover { background: rgba(255,255,255,.02); }
.dim-val { font-family: 'Exo 2', monospace; font-weight: 700; color: var(--cyan); }

/* ── MANDELBROT ──────────────────── */
.fr-mand-formula {
  font-family: 'Exo 2', monospace; font-size: 1.2rem;
  color: var(--cyan); text-align: center;
  background: rgba(34,211,238,.07); border: 1px solid rgba(34,211,238,.2);
  border-radius: 8px; padding: 14px; margin: 18px 0;
}

.fr-mandelbrot-interactive { margin: 18px 0; }
#mandelbrotMain { display: block; width: 100%; max-width: 560px; height: auto; border: 1px solid var(--border); border-radius: 8px; cursor: crosshair; }

.fr-mand-controls { display: flex; gap: 10px; align-items: center; margin-top: 10px; flex-wrap: wrap; }
.fr-mand-controls button {
  background: rgba(168,85,247,.15); border: 1px solid rgba(168,85,247,.3);
  color: var(--purple); padding: 6px 16px; border-radius: 6px;
  font-size: 0.82rem; cursor: pointer; transition: all 0.2s;
}
.fr-mand-controls button:hover { background: rgba(168,85,247,.3); }
.fr-mand-info { font-size: 0.78rem; color: var(--text2); }

/* ── IFS ─────────────────────────── */
.fr-ifs-grid { display: grid; grid-template-columns: auto 1fr; gap: 24px; align-items: start; }
.fr-ifs-canvas-wrap { text-align: center; }
#ferCanvas { display: block; border: 1px solid var(--border); border-radius: 8px; background: #000; }
.fr-canvas-label { font-size: 0.78rem; color: var(--text2); margin-top: 6px; }

.fr-ifs-table { width: 100%; border-collapse: collapse; font-size: 0.82rem; margin-bottom: 14px; }
.fr-ifs-table th { background: rgba(255,255,255,.04); color: var(--text2); padding: 7px 10px; text-align: left; border-bottom: 1px solid var(--border); font-size: 0.72rem; }
.fr-ifs-table td { padding: 7px 10px; border-bottom: 1px solid var(--border); color: var(--text2); font-family: 'Exo 2', monospace; }
.fr-ifs-table tr:last-child td { border-bottom: none; }
.fr-ifs-table-wrap p { font-size: 0.85rem; color: var(--text2); line-height: 1.7; margin: 0; }

/* ── NATURE ──────────────────────── */
.fr-nature-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; }
.fr-nat-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 10px; padding: 16px; }
.fr-nat-icon { font-size: 1.6rem; display: block; margin-bottom: 8px; }
.fr-nat-card h4 { font-size: 0.85rem; font-weight: 700; color: var(--green); margin-bottom: 6px; }
.fr-nat-card p  { font-size: 0.82rem; color: var(--text2); margin: 0; line-height: 1.7; }

/* ── APPLICATIONS ────────────────── */
.fr-app-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 12px; }
.fr-app-card { background: var(--bg2); border: 1px solid var(--border); border-radius: 10px; padding: 16px; }
.fr-app-card h4 { font-size: 0.85rem; font-weight: 700; color: var(--cyan); margin-bottom: 8px; }
.fr-app-card p  { font-size: 0.82rem; color: var(--text2); margin: 0; line-height: 1.7; }

/* ── FOOTER ──────────────────────── */
.fr-footer { border-top: 1px solid var(--border); background: var(--bg2); padding: 20px 32px; }
.fr-footer-inner { max-width: 1000px; margin: 0 auto; display: flex; align-items: center; gap: 14px; font-size: 0.8rem; color: var(--text2); }
.fr-footer-logo { font-size: 1.4rem; color: var(--purple); }

/* ── RESPONSIVE ──────────────────── */
@media (max-width: 768px) {
  .fr-def-cards, .fr-autosim-grid, .fr-nature-grid, .fr-app-grid { grid-template-columns: 1fr; }
  .fr-ifs-grid { grid-template-columns: 1fr; }
  .fr-examples-row { flex-direction: column; }
  .fr-dim-th, .fr-dim-tr { grid-template-columns: 2fr 1fr 1fr; }
  .fr-dim-tr span:nth-child(3) { display: none; }
}