:root {
  --bg: #050816;
  --bg-soft: rgba(12, 14, 34, 0.78);
  --panel: rgba(13, 17, 40, 0.94);
  --panel-border: rgba(147, 162, 255, 0.18);
  --text: #f2f5ff;
  --muted: #a7b2d8;
  --accent: #7aa2ff;
  --accent-strong: #b388ff;
  --accent-soft: #9dc5ff;
  --accent-pink: #cf89ff;
  --grid: rgba(148, 160, 221, 0.18);
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.36);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Space Grotesk", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(122, 162, 255, 0.18), transparent 32%),
    radial-gradient(circle at top right, rgba(179, 136, 255, 0.16), transparent 30%),
    radial-gradient(circle at bottom center, rgba(120, 74, 255, 0.12), transparent 28%),
    linear-gradient(145deg, #030510 0%, #060a18 42%, #0a1030 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='320' height='320' viewBox='0 0 320 320'%3E%3Cg fill='rgba(255,255,255,0.12)' font-family='Space Grotesk, sans-serif' font-size='14'%3E%3Ctext x='28' y='42'%3E%CF%80%3C/text%3E%3Ctext x='112' y='88'%3Ei%3C/text%3E%3Ctext x='202' y='52'%3E%2B%3C/text%3E%3Ctext x='260' y='112'%3E%CF%83%3C/text%3E%3Ctext x='56' y='152'%3E%CF%80%3C/text%3E%3Ctext x='154' y='182'%3Ex%3C/text%3E%3Ctext x='244' y='214'%3Ei%3C/text%3E%3Ctext x='84' y='248'%3E%2B%3C/text%3E%3Ctext x='184' y='278'%3E%CF%80%3C/text%3E%3Ctext x='276' y='286'%3Ex%3C/text%3E%3C/g%3E%3C/svg%3E");
  background-size: 320px 320px;
  opacity: 0.18;
  mask-image: radial-gradient(circle at center, black 48%, transparent 95%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 20% 30%, rgba(122, 162, 255, 0.14), transparent 22%),
    radial-gradient(circle at 78% 18%, rgba(179, 136, 255, 0.12), transparent 20%),
    radial-gradient(circle at 66% 74%, rgba(122, 162, 255, 0.1), transparent 24%);
  opacity: 0.5;
}

.page-shell {
  width: min(1380px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
}

.hero {
  display: block;
  margin-bottom: 24px;
}

.hero-copy,
.panel {
  border: 1px solid var(--panel-border);
  background: var(--bg-soft);
  backdrop-filter: blur(18px);
  box-shadow: var(--shadow);
}

.hero-copy {
  padding: 32px;
  border-radius: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.24em;
  font-size: 0.78rem;
  color: var(--accent);
}

h1,
h2 {
  font-family: "Unbounded", sans-serif;
  margin: 0;
}

h1 {
  font-size: clamp(3rem, 7vw, 5.5rem);
  line-height: 0.95;
}

.hero-text {
  max-width: 58ch;
  margin: 18px 0 0;
  font-size: 1.04rem;
  color: var(--muted);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  font: inherit;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button-primary {
  color: #f8fbff;
  background: linear-gradient(120deg, var(--accent) 0%, var(--accent-strong) 100%);
  box-shadow: 0 14px 34px rgba(122, 162, 255, 0.34);
}

.button-ghost {
  color: var(--text);
  background: rgba(122, 162, 255, 0.1);
  border: 1px solid rgba(162, 179, 255, 0.18);
}

.button.is-active {
  color: #f8fbff;
  background: linear-gradient(120deg, var(--accent) 0%, var(--accent-strong) 100%);
  box-shadow: 0 14px 34px rgba(122, 162, 255, 0.34);
}

.stat-label,
.panel-heading p,
.canvas-topline p,
.tips p,
.field span {
  color: var(--muted);
}


.playground {
  display: grid;
  grid-template-columns: minmax(320px, 420px) minmax(0, 1fr);
  gap: 24px;
}

.panel {
  border-radius: 28px;
  padding: 24px;
}

.panel-heading p,
.canvas-topline p,
.tips p {
  margin: 8px 0 0;
  line-height: 1.5;
}

.field {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

input[type="text"] {
  width: 100%;
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.09);
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
  font: inherit;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.slider-grid {
  margin-top: 10px;
}

.button-row {
  margin-top: 22px;
}

.tips {
  margin-top: 24px;
  padding: 18px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.04);
}

#status-message {
  color: var(--text);
  font-weight: 600;
}

.canvas-panel {
  min-width: 0;
}

.canvas-topline {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
}

#graph-canvas {
  width: 100%;
  display: block;
  border-radius: 24px;
  background:
    radial-gradient(circle at top, rgba(122, 162, 255, 0.1), transparent 30%),
    linear-gradient(180deg, rgba(7, 11, 28, 0.98), rgba(4, 7, 18, 1));
  border: 1px solid rgba(255, 255, 255, 0.07);
  cursor: grab;
}

#graph-canvas.dragging {
  cursor: grabbing;
}

code {
  color: var(--accent-soft);
}

@media (max-width: 1080px) {
  .playground {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(100% - 20px, 100%);
    padding-top: 12px;
  }

  .hero-copy,
  .panel {
    padding: 20px;
    border-radius: 22px;
  }

  h1 {
    font-size: clamp(2.5rem, 16vw, 4rem);
  }

  .canvas-topline {
    flex-direction: column;
  }
}