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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  color: #222;
  background: #fff;
}

.site-header {
  width: 100%;
  height: 54px;
  padding: 0 30px;
  background: #fff;
  border-bottom: 1px solid #d9d9d9;

  display: flex;
  align-items: center;
  justify-content: space-between;

  position: sticky;
  top: 0;
  left: 0;
  z-index: 1000;
}

.logo {
  display: flex;
  align-items: center;
  height: 100%;
}

.logo img {
  width: 64px;
  height: auto;
  display: block;
}

.navbar {
  height: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
}

.navbar a {
  color: #222;
  font-size: 16px;
  line-height: 1;
  text-decoration: none;
  padding: 11px 13px;
  white-space: nowrap;
}

.navbar a.active {
  color: #fff;
  background: #111;
}

.search-btn {
  width: 42px;
  height: 54px;

  display: flex;
  align-items: center;
  justify-content: center;

  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;

  color: #111;
  font-size: 0;
}

.search-btn::before {
  content: "";
  width: 15px;
  height: 15px;

  border: 2px solid #111;
  border-radius: 50%;

  position: relative;
  display: block;
}

.search-btn::after {
  content: "";
  width: 8px;
  height: 2px;

  background: #111;

  position: absolute;
  transform: translate(8px, 8px) rotate(48deg);
}

.hero {
  position: relative;
  width: 100%;
  height: calc(100vh - 54px);
  overflow: hidden;
  background: #fff;
}

.hero-banner {
  position: absolute;
  top: 0;
  left: 0;

  width: 100%;
  height: 100%;

  display: block;
  object-fit: cover;
  object-position: center center;
}

.down-btn {
  position: absolute;
  left: 50%;
  bottom: 20px;

  transform: translateX(-50%) rotate(45deg);

  width: 20px;
  height: 20px;

  border: 0;
  border-right: 4px solid #444;
  border-bottom: 4px solid #444;

  background: transparent;
  cursor: pointer;

  font-size: 0;
  z-index: 10;
}

.content-section {
  padding: 42px 0 80px;
}

.article-box {
  width: 75%;
  max-width: 1280px;
  margin: 0 auto;
}

.article-box p {
  font-size: 18px;
  line-height: 1.55;
  letter-spacing: 0.2px;
  margin-bottom: 22px;
  text-align: justify;
}

.red-line {
  width: 75%;
  max-width: 1280px;
  height: 4px;
  background: #ff6b6b;
  margin: 38px auto 52px;
}

.cert-section {
  width: 75%;
  max-width: 1280px;
  margin: 0 auto;
  text-align: center;
}

.cert-section h2 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.4px;
  margin-bottom: 70px;
}

.cert-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 54px 34px;
  align-items: center;
  justify-items: center;
}

.cert-grid img {
  width: 100%;
  max-width: 410px;
  height: auto;
  display: block;
}

.cert-grid img:nth-child(7) {
  grid-column: 1 / 2;
  margin-left: 55%;
}

.cert-grid img:nth-child(8) {
  grid-column: 2 / 3;
  margin-left: 55%;
}

.content-section {
  padding: 42px 0 80px;
  scroll-margin-top: 54px;
}

@media (max-width: 1024px) {
  .article-box,
  .red-line,
  .cert-section {
    width: 86%;
  }

  .cert-grid {
    gap: 36px 24px;
  }
}

@media (max-width: 768px) {
  .site-header {
    height: auto;
    padding: 12px 18px;
    align-items: flex-start;
  }

  .navbar {
    gap: 6px;
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .navbar a {
    font-size: 14px;
    padding: 8px 9px;
  }

  .hero {
    min-height: auto;
  }

  .down-btn {
    font-size: 42px;
    bottom: 10px;
  }

  .article-box,
  .red-line,
  .cert-section {
    width: 90%;
  }

  .article-box p {
    font-size: 16px;
  }

  .cert-grid {
    grid-template-columns: 1fr;
  }

  .cert-grid img:nth-child(7),
  .cert-grid img:nth-child(8) {
    grid-column: auto;
    margin-left: 0;
  }
}