/* Brand */
:root {
  --primary: #49d7ac;
  --bg: #1d252e;
  --text: #fff;
  --muted: rgba(255,255,255,.7);
  --line: rgba(255,255,255,.12);
  --header-offset: 80px; /* adjust if header height changes */
}

/* Base */
* { box-sizing: border-box; }
html, body {
  margin: 0;
  padding: 0;
  font-family: Poppins, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}
html { scroll-behavior: smooth; }

/* Layout helpers */
.container { max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.row { display: flex; gap: 12px; }
.center { align-items: center; }
.between { justify-content: space-between; }
.small { font-size: 12px; opacity: .8; }
.grid2 { display: grid; grid-template-columns: 1fr; gap: 28px; }
.grid3 { display: grid; grid-template-columns: 1fr; gap: 16px; }
@media (min-width: 900px) {
  .grid2 { grid-template-columns: 1.2fr .8fr; align-items: center; }
  .grid3 { grid-template-columns: repeat(3, 1fr); }
}

/* Header */
.topbar {
  position: sticky; top: 0; z-index: 50;
  border-bottom: 1px solid var(--line);
  background: rgba(29,37,46,.6);
  backdrop-filter: blur(8px);
}
.topbar .brand { font-weight: 600; }
.topbar .nav a { color: var(--muted); text-decoration: none; margin-left: 16px; }
.topbar .nav a:hover { color: var(--text); }
.logo-img { height: 70px; width: auto; margin-right: 8px; display: block; }

/* Hero */
.hero { padding: 56px 0; }
.hero h1 { font-size: 40px; margin: 0 0 12px; }
.hero p { opacity: .8; margin: 0 0 20px; }
.hero-center {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
  padding: 60px 20px 40px;
}

/* Sections */
section { scroll-margin-top: var(--header-offset); }
.section { padding: 48px 0; border-top: 1px solid var(--line); }
.section.alt { background: #11171d; }

/* Content blocks */
.feature h3 { margin: 0 0 6px; font-size: 18px; }
.feature p { margin: 0; opacity: .8; }

.card-lite {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  background: rgba(255,255,255,.03);
}
.use-case-blocks { text-align: center; margin-top: -30px; }
.use-case-blocks .card-lite {
  padding: 24px 16px;
  border-radius: 12px;
  font-size: 18px;
  font-weight: 600;
}

/* Forms & footer */
.form { display: grid; gap: 10px; grid-template-columns: 1fr; }
.form input {
  width: 100%;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.04);
  color: var(--text);
}
.social { gap: 16px; margin-top: 12px; }
.social a { color: var(--muted); text-decoration: none; }
.social a:hover { color: var(--text); }
.footer { border-top: 1px solid var(--line); padding: 16px 0; }

/* Buttons */
.btn {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 10px;
  text-decoration: none;
  border: 1px solid transparent;
  font-weight: 600;
}
.btn.btn-primary { background: var(--primary); color: #1d252e; }

/* Login page */
.login-container {
  max-width: 400px;
  margin: 120px auto;
  padding: 40px;
  background: #1d252e;
  border: 1px solid var(--line);
  border-radius: 12px;
  text-align: center;
  color: var(--text);
}
.login-container h1 { margin-bottom: 20px; }
.login-form { display: grid; gap: 12px; }
.login-form input {
  padding: 12px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.05);
  color: var(--text);
}
.back-link { display: block; margin-top: 16px; color: var(--primary); text-decoration: none; }
.back-link:hover { text-decoration: underline; }

/* Mobile header layout */
@media (max-width: 640px) {
  .topbar .container {
    flex-direction: column;   /* stack brand and nav */
    align-items: stretch;
    gap: 8px;
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .logo-img { height: 48px; }              /* slightly smaller logo */
  .topbar .brand { font-size: 18px; }

  .topbar .nav {
    display: flex;
    flex-wrap: wrap;                        /* allow wrapping */
    gap: 10px 14px;
    justify-content: space-between;
  }

  .topbar .nav a {                          /* smaller link text */
    margin: 0;
    font-size: 14px;
  }

  .btn.btn-primary {                        /* shrink the big green button */
    padding: 8px 10px;
    border-radius: 12px;
  }
}