:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --primary: #1f4cff;
  --text: #172033;
  --muted: #606d85;
  --line: #dfe8f6;
  --shadow: 0 18px 45px rgba(23, 32, 51, 0.08);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.container {
  width: min(1100px, calc(100% - 28px));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(244, 247, 251, 0.9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.bar {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  text-decoration: none;
  color: var(--text);
  font-weight: 800;
}

nav {
  display: flex;
  align-items: center;
  gap: 18px;
}

nav a {
  text-decoration: none;
  color: var(--muted);
}

.demo-shell {
  padding: 42px 0 80px;
}

.page-header {
  margin-bottom: 20px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.72rem;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(2.1rem, 4vw, 3.3rem);
  letter-spacing: -0.05em;
}

.two-column {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 24px;
}

.panel-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 14px;
}

.activity-list,
.report ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.output-panel h3 {
  margin: 16px 0 8px;
}

.report p,
.report li {
  color: var(--muted);
}

.actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  font-weight: 700;
  text-decoration: none;
  padding: 14px 22px;
}

.button.primary {
  background: var(--primary);
  color: #fff;
}

.button.secondary {
  background: #edf2ff;
  border: 1px solid var(--line);
  color: var(--text);
}

@media (max-width: 768px) {
  .two-column {
    grid-template-columns: 1fr;
  }

  .bar {
    flex-direction: column;
    justify-content: center;
    padding: 12px 0;
  }
}