:root {
  --ink: #0d1e27;
  --sea: #0ea5b3;
  --sea-dark: #046b76;
  --foam: #e9faff;
  --bg: #f7fbff;
  --radius: 12px;
  --shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: system-ui, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  text-align: center;
}

.container {
  width: min(1000px, 92%);
  margin: 0 auto;
}

.header {
  position: sticky;
  top: 0;
  background: white;
  box-shadow: var(--shadow);
  z-index: 100;
}
.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
}
.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--sea);
}
nav a {
  text-decoration: none;
  color: var(--ink);
  margin-left: 1.2rem;
  font-weight: 600;
}
nav a:hover {
  color: var(--sea-dark);
}

.section {
  padding: 4rem 0;
}
.section.alt {
  background: var(--foam);
}
.section h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--sea-dark);
}
.section p {
  font-size: 1.05rem;
  max-width: 65ch;
  margin: 0 auto 1.5rem;
}

.tech-list {
  list-style: none;
  text-align: left;
  display: inline-block;
  margin: 0 auto;
  line-height: 1.8;
}
.tech-list li::before {
  content: "• ";
  color: var(--sea);
  font-weight: bold;
}

.example-video {
  margin-top: 1rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.btn.primary {
  display: inline-block;
  background: var(--sea);
  color: white;
  padding: 0.7rem 1.2rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s ease;
  margin-top: 1rem;
}
.btn.primary:hover {
  background: var(--sea-dark);
}

.footer {
  text-align: center;
  padding: 2rem 0;
  font-size: 0.95rem;
  color: #445;
  border-top: 1px solid #dde;
  background: white;
}