:root {
  --bg: #0f1724;
  --card: #071027;
  --accent: #7c3aed;
  --muted: #9aa4b2;
  --white: #e6eef6;
  --danger: #ef4444;
  font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, Arial;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: #002252;
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 28px;
}

.card {
  width: min(820px, 96%);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(255, 255, 255, 0.01));
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 8px 30px rgba(2, 6, 23, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.03);
}

header {
  display: flex;
  gap: 14px;
  align-items: center;
}

.logo {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), #22c1c3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: 18px;
}

.lead {
  margin: 4px 0 12px;
  color: var(--muted);
  font-size: 14px;
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 18px;
  align-items: start;
}

@media (max-width:800px) {
  .calc-grid {
    grid-template-columns: 1fr;
  }
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.controls label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 14px;
  color: var(--muted);
}

.controls input[type="number"] {
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.04);
  background: transparent;
  color: inherit;
  outline: none;
}

.controls input:focus {
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.08);
  border-color: rgba(99, 102, 241, 0.6);
}

.tip-buttons .buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.tipBtn {
  padding: 10px 12px;
  border-radius: 8px;
  border: 0;
  background: linear-gradient(90deg, var(--accent), #22c1c3);
  color: white;
  font-weight: 600;
  cursor: pointer
}

.tipBtn.inactive {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--muted)
}

.tip-buttons input {
  padding: 8px 10px;
  min-width: 80px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.04);
  background: transparent;
  color: inherit;
}

.form-actions {
  display: flex;
  gap: 8px;
  margin-top: 6px;
}

.btn {
  padding: 10px 14px;
  border-radius: 10px;
  border: 0;
  background: linear-gradient(90deg, var(--accent), #22c1c3);
  color: white;
  font-weight: 600;
  cursor: pointer
}

.btn.secondary {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.06);
  color: var(--muted)
}

.results {
  background: rgba(255, 255, 255, 0.02);
  padding: 16px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.03);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.label {
  color: var(--muted);
  font-size: 14px;
}

.value {
  font-family: ui-monospace, monospace;
  font-size: 20px;
  font-weight: 700;
}

.muted {
  font-size: 12px;
  color: var(--muted)
}

.error {
  color: var(--danger);
  font-size: 13px;
  min-height: 18px
}

.small {
  font-size: 13px;
  color: var(--muted)
}