:root {
  --bg: #0f1115;
  --card: #1a1d24;
  --text: #e8e8ea;
  --muted: #9a9ca3;
  --accent: #5b8def;
  --accent-hover: #4a78d4;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

header {
  padding: 2rem 1rem 1rem;
  text-align: center;
}

header h1 {
  font-size: 1.8rem;
  margin-bottom: 0.3rem;
}

header p {
  color: var(--muted);
}

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.card {
  background: var(--card);
  border-radius: 12px;
  padding: 1.2rem;
  text-decoration: none;
  color: var(--text);
  display: block;
  border: 1px solid #2a2d36;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.card h2 {
  font-size: 1.05rem;
  margin-bottom: 0.3rem;
}

.card p {
  color: var(--muted);
  font-size: 0.9rem;
}

.tool-box {
  background: var(--card);
  border-radius: 12px;
  padding: 1.5rem;
  border: 1px solid #2a2d36;
  max-width: 500px;
  margin: 0 auto;
}

.tool-box label {
  display: block;
  margin-bottom: 0.4rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.tool-box input {
  width: 100%;
  padding: 0.6rem;
  border-radius: 8px;
  border: 1px solid #2a2d36;
  background: #0f1115;
  color: var(--text);
  font-size: 1rem;
  margin-bottom: 1rem;
}

.tool-box button {
  background: var(--accent);
  color: white;
  border: none;
  padding: 0.7rem 1.2rem;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  width: 100%;
}

.tool-box button:hover {
  background: var(--accent-hover);
}

.result {
  margin-top: 1.2rem;
  padding: 1rem;
  background: #0f1115;
  border-radius: 8px;
  font-size: 1.1rem;
  text-align: center;
  min-height: 1.5rem;
}

.back-link {
  display: inline-block;
  margin-bottom: 1.2rem;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}

.back-link:hover { color: var(--accent); }

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
  padding: 2rem 1rem;
}