:root {
  --bg: #f3f5f7;
  --card: #ffffff;
  --ink: #1a202c;
  --muted: #5a6472;
  --primary: #0b6bcb;
  --accent: #0f9d8a;
  --danger: #b42318;
  --border: #d6dbe3;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% -10%, #dbeafe 0, transparent 40%),
    radial-gradient(circle at 90% 0%, #d1fae5 0, transparent 35%),
    var(--bg);
}

.app-shell {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

h1, h2, h3 { margin: 0 0 0.75rem; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1rem;
  box-shadow: 0 10px 30px rgba(2, 6, 23, 0.06);
  margin-bottom: 1rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.panel {
  background: #fbfcfe;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.9rem;
}

.register-details {
  margin-top: 0.8rem;
}

.register-details summary {
  cursor: pointer;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

label {
  display: block;
  margin-bottom: 0.6rem;
  color: var(--muted);
  font-size: 0.92rem;
}

input, select, button, textarea {
  width: 100%;
  margin-top: 0.25rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.6rem 0.7rem;
  font: inherit;
}

button {
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
}

button.ghost {
  background: #e8eef6;
  color: #1f2937;
}

button:disabled { opacity: 0.5; cursor: not-allowed; }

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tab {
  width: auto;
  background: #e8eef6;
  color: #1f2937;
  padding: 0.5rem 0.8rem;
}

.tab.active {
  background: var(--accent);
  color: #fff;
}

.tab-panel { display: none; }
.tab-panel.active { display: block; }

.list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.list li {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.7rem;
  font-size: 0.9rem;
}

.list-row {
  display: flex;
  justify-content: space-between;
  gap: 0.7rem;
  align-items: center;
}

.list-actions {
  display: flex;
  gap: 0.35rem;
}

.mini {
  width: auto;
  padding: 0.35rem 0.55rem;
  font-size: 0.82rem;
}

.calc-summary {
  background: #0b1020;
  color: #d7e2ff;
  border-radius: 10px;
  padding: 1rem;
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.8rem;
}

.calc-breakdown {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.5rem;
}

.calc-breakdown summary {
  cursor: pointer;
  font-weight: 600;
}

.message {
  position: sticky;
  bottom: 0;
  padding: 0.7rem 0.9rem;
  border-radius: 10px;
  background: #dbeafe;
  color: #1e3a8a;
  display: none;
}

.message.error {
  display: block;
  background: #fee2e2;
  color: var(--danger);
}

.message.success {
  display: block;
  background: #dcfce7;
  color: #166534;
}

.hidden { display: none; }

@media (min-width: 860px) {
  .grid-2 { grid-template-columns: 1fr 1fr; }
}