:root {
  --navy: #0d1b2a;
  --navy-2: #1b263b;
  --ink: #e0e6ed;
  --green: #2ec4a5;
  --green-dim: #1a7f6b;
  --warn: #ffd166;
  --max-w: 720px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--navy);
  color: var(--ink);
  line-height: 1.65;
  font-size: 18px;
}
header {
  background: var(--navy-2);
  padding: 1rem 1.5rem;
  border-bottom: 2px solid var(--green-dim);
}
header h1 { margin: 0; font-size: 1.4rem; }
header h1 a { color: var(--green); text-decoration: none; }
nav { margin-top: 0.5rem; }
nav a { color: var(--ink); text-decoration: none; margin-right: 1.25rem; }
nav a:hover, nav a:focus { color: var(--green); text-decoration: underline; }
main { max-width: var(--max-w); margin: 0 auto; padding: 1.5rem; }
h2 { color: var(--green); margin-top: 2rem; }
h3 { color: var(--ink); }
a { color: #6ec6ff; }
.tool-grid { display: grid; gap: 1rem; grid-template-columns: 1fr; }
@media (min-width: 640px) { .tool-grid { grid-template-columns: 1fr 1fr; } }
.card {
  background: var(--navy-2);
  border: 1px solid var(--green-dim);
  border-radius: 10px;
  padding: 1.25rem;
  display: block;
  color: var(--ink);
  text-decoration: none;
}
.card:hover, .card:focus { border-color: var(--green); }
.card strong { color: var(--green); display: block; font-size: 1.1rem; }
label { display: block; margin-top: 1rem; font-weight: 600; }
input, select {
  width: 100%;
  padding: 0.6rem;
  font-size: 1rem;
  border-radius: 6px;
  border: 1px solid #444;
  background: #10203a;
  color: var(--ink);
  margin-top: 0.3rem;
}
button {
  margin-top: 1.25rem;
  background: var(--green);
  color: var(--navy);
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 700;
  border-radius: 8px;
  cursor: pointer;
}
button:hover, button:focus { background: #3fd9b9; }
.result {
  margin-top: 1.25rem;
  background: #10203a;
  border-left: 4px solid var(--green);
  padding: 1rem;
  font-size: 1.15rem;
}
.result strong { color: var(--green); font-size: 1.4rem; }
.disclaimer {
  margin-top: 2.5rem;
  font-size: 0.85rem;
  color: #8fa3b8;
  border-top: 1px solid #2a3b55;
  padding-top: 1rem;
}
footer { text-align: center; padding: 2rem; color: #8fa3b8; font-size: 0.9rem; }
table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
th, td { border: 1px solid #2a3b55; padding: 0.5rem; text-align: left; }
th { background: var(--navy-2); color: var(--green); }