:root{
  --bg: #0b1220;
  --surface: #0f1b33;
  --text: #e6eaf2;
  --muted: rgba(230,234,242,0.75);
  --border: rgba(255,255,255,0.10);
  --accent: #4f7cff; /* blue */
}

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

body{
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}

a{ color: var(--accent); }
a:hover{ filter: brightness(1.08); }

header, footer{
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
footer{
  border-top: 1px solid var(--border);
  border-bottom: 0;
}

main{
  width: min(1000px, 92%);
  margin: 0 auto;
  padding: 24px 0;
}

nav a{
  display: inline-block;
  color: var(--text);
  text-decoration: none;
  padding: 8px 10px;
  margin-right: 10px;
  border-radius: 10px;
}
nav a:hover{
  background: rgba(255,255,255,0.08);
}

section{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin: 16px 0;
}

button, .btn{
  background: var(--accent);
  color: white;
  border: 0;
  border-radius: 12px;
  padding: 10px 12px;
  font-weight: 600;
  cursor: pointer;
}
button:hover, .btn:hover{ filter: brightness(1.05); }

input, textarea{
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.04);
  color: var(--text);
}
label{ color: var(--muted); }

/* Keep your calculator layout working */
.calculator {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}
.calculator input { padding: 10px; font-size: 18px; }
.calculator button { padding: 10px; font-size: 18px; cursor: pointer; }