body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background-color: #0f172a;
  color: #e2e8f0;
  padding: 2rem;
}
header {
  text-align: center;
  margin-bottom: 2rem;
}
h1 {
  font-size: 2.2rem;
  color: #38bdf8;
}
.subtitle {
  font-size: 1rem;
  color: #94a3b8;
}
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}
.tool-card {
  background-color: #1e293b;
  border-radius: 10px;
  padding: 1.5rem;
  box-shadow: 0 0 0 1px #334155;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.3s ease;
}
.tool-card:hover {
  transform: scale(1.03);
}
.tool-card h3 {
  color: #f1f5f9;
  margin-top: 0;
}
.tool-card p {
  color: #cbd5e1;
  margin: 0.5rem 0 1rem;
}
.btn-open {
  background-color: #3b82f6;
  color: white;
  padding: 0.5rem 1rem;
  text-decoration: none;
  border-radius: 5px;
  text-align: center;
  transition: background-color 0.3s;
}
.btn-open:hover {
  background-color: #2563eb;
}
footer {
  text-align: center;
  margin-top: 4rem;
  font-size: 0.85rem;
  color: #64748b;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
}

.topbar .brand {
  font-size: 20px;
  font-weight: bold;
  text-decoration: none;
  color: var(--muted);
}

.topbar .btn {
  background: var(--card);
  border: 1px solid var(--line);
  color: var(--white);
  padding: 8px 14px;
  border-radius: 8px;
  text-decoration: none;
  transition: all 0.2s ease;
}

.topbar .btn:hover {
  background: var(--hover);
}

.btn-primary {
  background-color: #2563eb;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  display: inline-block;
  transition: background-color 0.2s ease;
}
.btn-primary:hover {
  background-color: #1e40af;
}