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

body {
  font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Roboto, Arial;
  color: #111;
  background: #fff;
  line-height: 1.6;
}

/* HEADER */
.header {
  position: fixed;
  top: 0;
  width: 100%;
  background: #fff;
  padding: 16px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 20px rgba(0,0,0,.06);
  z-index: 1000;
}

.logo {
  font-weight: 800;
  font-size: 18px;
}

.header nav a {
  margin-left: 20px;
  text-decoration: none;
  color: #111;
  font-weight: 500;
}

/* HERO */
.hero {
  height: 100vh;
  background: linear-gradient(120deg,#0f2027,#203a43,#2c5364);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  text-align: center;
  padding: 20px;
}

.hero h1 {
  font-size: 48px;
  margin-bottom: 12px;
}

/* SECTIONS */
.section {
  max-width: 1100px;
  margin: auto;
  padding: 100px 20px;
}

.section.gray {
  background: #f4f6f8;
}

.section h2 {
  font-size: 32px;
  margin-bottom: 24px;
}

/* CARDS */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit,minmax(260px,1fr));
  gap: 24px;
}

.card {
  background: #fff;
  padding: 30px;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0,0,0,.08);
}

/* LIST */
.list {
  list-style: none;
  font-size: 18px;
}

.list li {
  padding: 10px 0;
}

/* FOOTER */
.footer {
  text-align: center;
  padding: 30px;
  background: #111;
  color: #aaa;
}

/* MOBILE */
@media(max-width:768px) {
  .hero h1 {
    font-size: 32px;
  }
  .header nav {
    display: none;
  }
}