:root {
  --bg: #0f0f0f;
  --card: #501818;
  --text: #10beea;
  --muted: #9ca3af;
  --accent: #426cb0;
  --green: #316d47;
  --border: #2d2d2d;
}

body.light {
  --bg: #f9f9f9;
  --card: #ffffff;
  --text: #222222;
  --muted: #555555;
  --accent: #2563eb;
  --green: #16a34a;
  --border: #dddddd;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background 0.3s, color 0.3s;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--card);
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--text);
}

.menu-btn, .toggle-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
  color: var(--text);
}

.menu-panel {
  position: absolute;
  top: 60px;
  left: 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: none;
  flex-direction: column;
  padding: 10px;
}

.menu-panel.show { display: flex; }

.menu-panel ul { list-style: none; margin: 0; padding: 0; }
.menu-panel li { margin: 8px 0; }
.menu-panel a { text-decoration: none; color: var(--muted); font-weight: 500; }
.menu-panel a:hover { color: var(--accent); }

.hero {
  text-align: center;
  padding: 60px 20px;
  background: var(--card);
  margin-bottom: 20px;
}
.hero h1 { font-size: 2rem; margin-bottom: 10px; }
.hero p { color: var(--muted); font-size: 1.1rem; }

.container {
  max-width: 1024px;
  margin: 32px auto;
  padding: 0 16px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  margin-bottom: 18px;
  transition: background 0.3s, border 0.3s;
}

h1, h2 { margin: 0 0 12px; }
form { margin-top: 8px; }

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.field { display: flex; flex-direction: column; gap: 6px; }
label { color: var(--muted); font-size: 0.95rem; }
input, select {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  outline: none;
}
input:focus, select:focus { border-color: var(--accent); }

.primary {
  margin-top: 14px;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 10px 16px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 600;
}
.primary:hover { opacity: 0.95; }

.results {
  margin-top: 12px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}
.metric {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
}
.metric .label { color: var(--muted); }
.metric .value { font-weight: 600; font-size: 1.1rem; color: var(--green); }

.side-by-side {
  display: flex;
  gap: 20px;
}
.results-card, .chart-card {
  flex: 1;
}

@media (max-width: 900px) {
  .side-by-side { flex-direction: column; }
}