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

:root {
  --bg: #0d0d1a;
  --surface: #161628;
  --surface2: #1e1e38;
  --accent: #7c6cf5;
  --accent2: #4ecdc4;
  --text: #e8e8f0;
  --text-dim: #8888aa;
  --radius: 12px;
  --gap: 1rem;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', system-ui, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1.5rem 1rem 3rem;
}

/* ── Header ── */
header { text-align: center; margin-bottom: 2rem; }
header h1 { font-size: clamp(1.8rem, 5vw, 3rem); letter-spacing: -0.5px; }
.subtitle { color: var(--text-dim); margin-top: 0.4rem; font-size: 1rem; }

/* ── Home nav grid ── */
.module-nav {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--gap);
  width: 100%;
  max-width: 900px;
}

.nav-card {
  background: var(--surface);
  border: 1px solid var(--surface2);
  border-radius: var(--radius);
  padding: 1.5rem 1rem;
  text-decoration: none;
  color: var(--text);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  transition: background 0.2s, transform 0.15s;
}
.nav-card:hover { background: var(--surface2); transform: translateY(-3px); }
.nav-icon { font-size: 2rem; }
.nav-label { font-size: 0.9rem; font-weight: 600; text-align: center; }

/* ── Module page layout ── */
.module-page {
  width: 100%;
  max-width: 960px;
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}
.back-link:hover { text-decoration: underline; }

/* ── Canvas container ── */
.canvas-wrap {
  background: var(--surface);
  border: 1px solid var(--surface2);
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
  width: 100%;
}
.canvas-wrap canvas {
  display: block;
  width: 100%;
  height: auto;
}

/* ── Stats bar ── */
.stats-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  background: var(--surface);
  border: 1px solid var(--surface2);
  border-radius: var(--radius);
  padding: 0.8rem 1rem;
}
.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 90px;
}
.stat-label { font-size: 0.72rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.05em; }
.stat-value { font-size: 1.1rem; font-weight: 700; color: var(--accent2); }

/* ── Controls panel ── */
.controls-toggle {
  background: var(--surface2);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  padding: 0.5rem 1.2rem;
  color: var(--accent);
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  align-self: flex-start;
  transition: background 0.2s;
}
.controls-toggle:hover { background: var(--accent); color: #fff; }

.controls-panel {
  background: var(--surface);
  border: 1px solid var(--surface2);
  border-radius: var(--radius);
  padding: 1.2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}
.controls-panel.hidden { display: none; }

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.control-group label {
  font-size: 0.82rem;
  color: var(--text-dim);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.control-group input[type=range] {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
}
.control-group input[type=number],
.control-group select {
  background: var(--surface2);
  border: 1px solid var(--accent);
  border-radius: 6px;
  color: var(--text);
  padding: 0.3rem 0.5rem;
  font-size: 0.9rem;
  width: 100%;
}

/* ── Buttons ── */
.btn {
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: #fff;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.55rem 1.2rem;
  transition: opacity 0.2s;
}
.btn:hover { opacity: 0.85; }
.btn.secondary { background: var(--surface2); color: var(--accent); border: 1px solid var(--accent); }

/* ── Description box ── */
.description {
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 0.9rem 1.1rem;
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.6;
}

footer { margin-top: 3rem; color: var(--text-dim); font-size: 0.8rem; }

/* ── Mobile tweaks ── */
@media (max-width: 480px) {
  .stats-bar { justify-content: center; }
  .stat { min-width: 70px; }
  .stat-value { font-size: 0.95rem; }
}