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

body {
  font-family: Arial, Helvetica, sans-serif;
  background: #111315;
  color: #f4f5f6;
  line-height: 1.6;
}

.container {
  width: 90%;
  max-width: 1280px;
  margin: auto;
}

/* HEADER */

.header {
  background: rgba(10, 10, 12, 0.94);
  border-bottom: 1px solid #222;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav {
  height: 90px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  flex-direction: column;
  line-height: 1;
}

.brand-main {
  font-size: 2rem;
  font-weight: 700;
  color: #7A102E;
  letter-spacing: 1px;
}

.brand-sub {
  font-size: 0.78rem;
  color: #888;
  margin-top: 8px;
  letter-spacing: 2px;
}

nav {
  display: flex;
  gap: 2rem;
}

nav a {
  color: #f4f5f6;
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.3s ease;
}

nav a:hover {
  color: #d40012;
}

/* HERO */

.hero {
  height: 85vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;

  background:
    linear-gradient(
      to right,
      rgba(8, 10, 12, 0.96) 0%,
      rgba(8, 10, 12, 0.88) 35%,
      rgba(8, 10, 12, 0.82) 100%
    ),
    url('./images/hero.jpg');

  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}

.hero-content {
  max-width: 760px;
}

.hero h1 {
  font-size: 5rem;
  line-height: 0.95;
  margin-bottom: 1.5rem;
  max-width: 700px;
}

.hero p {
  font-size: 1.2rem;
  color: #b5b9bd;
  margin-bottom: 2.5rem;
  max-width: 620px;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
}

.btn-primary,
.btn-secondary {
  padding: 14px 28px;
  text-decoration: none;
  border-radius: 0;
  transition: all 0.3s ease;
}

.btn-primary {
  background: #d40012;
  color: #ffffff;
}

.btn-primary:hover {
  background: #f00015;
}

.btn-secondary {
  border: 1px solid #555;
  color: #ffffff;
}

.btn-secondary:hover {
  border-color: #ffffff;
}

/* SECTIONS */

.section {
  padding: 100px 0;
}

.dark-section {
  background: #16191c;
}

.valve-io {
  background: #0d0f11;
}

.section-title {
  margin-bottom: 3rem;
}

.section-title h2 {
  font-size: 2.5rem;
}

.section-title h2::after {
  content: "";
  display: block;
  width: 70px;
  height: 2px;
  background: #d40012;
  margin-top: 14px;
}

.section-text {
  max-width: 760px;
  color: #aaa;
  font-size: 1.1rem;
  margin-bottom: 3rem;
}

/* CARDS */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.card {
  background: #1b1f23;
  padding: 2rem;
  border: 1px solid #222;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  border-color: #d40012;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

.card h3 {
  margin-bottom: 1rem;
}

.card p {
  color: #aaa;
}

/* FOOTER */

.footer {
  border-top: 1px solid #222;
  padding: 2rem 0;
  text-align: center;
  color: #777;
}

/* MOBILE */

@media(max-width: 900px) {
  .nav {
    flex-direction: column;
    height: auto;
    padding: 1rem 0;
    gap: 1rem;
  }

  nav {
    flex-wrap: wrap;
    justify-content: center;
  }

  .brand {
    align-items: center;
  }

  .brand-main {
    font-size: 1.7rem;
  }

  .brand-sub {
    font-size: 0.68rem;
  }

  .hero {
    height: 80vh;
  }

  .hero h1 {
    font-size: 2.8rem;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: flex-start;
  }
}