:root{
  --bg: #044702;         
  --card: #39ac17;       
  --muted: #94a3b8;      
  --text: #e5e7eb;       
  --primary: #22c55e;    
  --primary-strong: #16a34a; 
  --ring: rgba(34,197,94,0.35);
  --shadow: 0 10px 30px rgba(0,0,0,0.3);
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  background: radial-gradient(1200px 600px at 10% 0%, #0b1222 0%, var(--bg) 60%);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  line-height: 1.5;
}

.container {
  max-width: 980px;
  margin: 2rem auto 4rem;
  padding: 0 1rem;
}

.site-header {
  padding: 2rem 1rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand-icon {
  width: 54px; height: 54px;
  display: grid; place-items: center;
  font-size: 28px;
  background: linear-gradient(135deg, #22c55e, #a3e635);
  color: #0b1222;
  border-radius: 12px;
  box-shadow: var(--shadow);
}

h1 {
  font-size: clamp(1.6rem, 1.2rem + 2vw, 2.4rem);
  margin: 0;
  letter-spacing: 0.3px;
}
.tagline { color: var(--muted); margin: 0.2rem 0 0; }

.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
  backdrop-filter: blur(6px);
  margin-top: 1rem;
}

.intro p { margin-top: 0.25rem; color: #cbd5e1; }

.features {
  display: grid;
  gap: 0.4rem;
  padding-left: 1.1rem;
  margin: 0.8rem 0 0.2rem;
}
.features li { color: #d1d5db; }

.calculator h2, .intro h2 {
  margin: 0.25rem 0 0.75rem;
  font-size: 1.25rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

@media (max-width: 720px) {
  .grid { grid-template-columns: 1fr; }
}

.field {
  display: grid;
  gap: 0.5rem;
}

.field span {
  color: var(--muted);
  font-size: 0.9rem;
}

input[type="number"] {
  width: 100%;
  padding: 0.8rem 0.9rem;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(17,24,39,0.9);
  color: var(--text);
  outline: none;
  transition: border .2s, box-shadow .2s;
}

input[type="number"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--ring);
}

.actions {
  display: flex;
  gap: 0.8rem;
  margin-top: 1rem;
}

.btn {
  appearance: none;
  border: 1px solid rgba(255,255,255,0.12);
  padding: 0.75rem 1rem;
  border-radius: 12px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  transition: transform .06s ease-in-out, background .2s, border-color .2s;
}

.btn:hover {
  border-color: rgba(255,255,255,0.28);
  transform: translateY(-1px);
}

.btn.primary {
  background: linear-gradient(135deg, var(--primary), #a3e635);
  color: #08131f;
  border: none;
  font-weight: 600;
}
.btn.primary:hover { filter: brightness(1.05); }

.result {
  margin-top: 1.25rem;
  border-top: 1px dashed rgba(255,255,255,0.14);
  padding-top: 1rem;
}

.summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.summary .value {
  font-size: 1.25rem;
  margin-top: 0.15rem;
}

.summary .highlight {
  color: #052e16;
  background: linear-gradient(135deg, #bbf7d0, #86efac);
  border-radius: 10px;
  display: inline-block;
  padding: 0.25rem 0.5rem;
}

.breakdown {
  margin-top: 0.75rem;
  color: #d1d5db;
}

.breakdown summary {
  cursor: pointer;
  color: #c7f9cc;
}

.breakdown ul {
  margin: 0.5rem 0 0;
  padding-left: 1.1rem;
  color: #e5e7eb;
}

.note {
  margin-top: 0.8rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer {
  text-align: center;
  color: var(--muted);
  padding: 2rem 1rem 3rem;
  font-size: 0.9rem;
}