:root {
  --color-primary: #0b1f3a;
  --color-accent: #12aee6;
  --color-text: #1f2933;
  --color-muted: #667085;
  --color-border: #d9e0e8;
  --color-bg: #f3f6fa;
  --color-white: #ffffff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  color: var(--color-text);
  background:
    radial-gradient(circle at top left, rgba(18, 174, 230, 0.12), transparent 30rem),
    var(--color-bg);
}

a {
  color: inherit;
  text-decoration: none;
}

.catalog-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.9);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(18px);
}

.catalog-nav {
  width: min(100% - 32px, 1120px);
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: var(--color-primary);
  font-weight: 900;
}

.brand img {
  width: 58px;
  height: 58px;
  object-fit: contain;
}

.back-link {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(18, 174, 230, 0.28);
  border-radius: 10px;
  padding: 10px 14px;
  color: var(--color-primary);
  background: var(--color-white);
  font-weight: 800;
}

.catalog-wrap {
  width: min(100% - 32px, 1180px);
  margin: 0 auto;
  padding: 34px 0;
}

.catalog-title {
  margin-bottom: 22px;
}

.catalog-title p {
  margin: 0 0 8px;
  color: var(--color-accent);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.catalog-title h1 {
  margin: 0;
  color: var(--color-primary);
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  line-height: 1.08;
}

.pdf-frame {
  width: 100%;
  height: min(78vh, 920px);
  min-height: 620px;
  border: 1px solid var(--color-border);
  border-radius: 18px;
  overflow: hidden;
  background: var(--color-white);
  box-shadow: 0 24px 70px rgba(11, 31, 58, 0.14);
}

.pdf-frame iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

.fallback {
  margin: 14px 0 0;
  color: var(--color-muted);
  font-size: 0.94rem;
}

.fallback a {
  color: var(--color-primary);
  font-weight: 800;
}

@media (max-width: 720px) {
  .catalog-nav {
    min-height: 70px;
  }

  .brand span {
    max-width: 160px;
    line-height: 1.12;
  }

  .brand img {
    width: 48px;
    height: 48px;
  }

  .back-link {
    padding: 9px 12px;
    font-size: 0.9rem;
  }

  .pdf-frame {
    min-height: 72vh;
    border-radius: 14px;
  }
}