:root {
  --bg: #101826;
  --panel: #19263d;
  --panel-2: #223354;
  --accent: #f5a524;
  --text: #f2f6ff;
  --danger: #ff5d73;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 20% 20%, #2c3d63, var(--bg) 50%);
}

.app {
  width: min(92vw, 420px);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.6rem 0.2rem;
}

.topbar h1 {
  margin: 0;
  font-size: 1.1rem;
  letter-spacing: 0.04em;
}

.topbar p {
  margin: 0;
  color: var(--accent);
  font-weight: 700;
}

.calculator {
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 16px;
  padding: 1rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
}

#display {
  width: 100%;
  margin-bottom: 0.9rem;
  border: none;
  border-radius: 10px;
  padding: 0.9rem;
  font-size: 1.6rem;
  text-align: right;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
}

.buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.buttons button {
  border: none;
  border-radius: 10px;
  padding: 0.85rem;
  font-size: 1rem;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
  cursor: pointer;
  transition: transform 0.08s ease, background 0.2s ease;
}

.buttons button:hover {
  background: rgba(255, 255, 255, 0.16);
}

.buttons button:active {
  transform: scale(0.98);
}

.equals {
  grid-row: span 2;
  background: var(--accent);
  color: #1d1610;
  font-weight: 700;
}

.zero {
  grid-column: span 2;
}

.paywall {
  position: fixed;
  inset: 0;
  background: rgba(10, 15, 30, 0.8);
  display: grid;
  place-items: center;
  padding: 1rem;
  z-index: 999;
}

.paywall-card {
  width: min(92vw, 430px);
  background: linear-gradient(180deg, #ffffff 0%, #f7efe4 100%);
  color: #1f1a14;
  border-radius: 20px;
  padding: 1.2rem;
  border: 1px solid rgba(23, 21, 17, 0.08);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
  animation: pop 0.22s ease;
}

@keyframes pop {
  from { transform: scale(0.9); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.paywall-head h2 {
  margin: 0.2rem 0 0.4rem;
  font-family: "Georgia", "Times New Roman", serif;
  font-size: 1.75rem;
  letter-spacing: 0.01em;
}

.eyebrow {
  margin: 0;
  font-size: 0.72rem;
  color: #7f6a4c;
  letter-spacing: 0.12em;
  font-weight: 700;
}

#paywallMessage {
  margin: 0;
  color: #46331a;
  line-height: 1.45;
}

.plans {
  display: grid;
  gap: 0.6rem;
  margin: 1rem 0 0.9rem;
}

.plan {
  border: 1px solid #efd9bc;
  border-radius: 12px;
  background: #fffaf2;
  color: #302211;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.2rem 0.4rem;
  text-align: left;
  padding: 0.75rem 0.8rem;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.plan:hover {
  border-color: #d5b78d;
  background: #fff4e2;
}

.plan-name {
  font-weight: 700;
  letter-spacing: 0.01em;
}

.plan-price {
  font-weight: 700;
}

.plan-tag {
  grid-column: span 2;
  font-size: 0.72rem;
  color: #0f3f2f;
  background: #c4f5dc;
  border-radius: 999px;
  width: fit-content;
  padding: 0.14rem 0.5rem;
}

.featured {
  border-color: #daa561;
  background: #fff0d8;
}

.buy-btn {
  width: 100%;
  border: none;
  border-radius: 12px;
  padding: 0.8rem 0.9rem;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(90deg, #101010, #2e2e2e);
  cursor: pointer;
}

.buy-btn:hover {
  filter: brightness(1.08);
}

.secure-note {
  margin: 0.62rem 0 0.8rem;
  font-size: 0.78rem;
  color: #6e5a41;
  text-align: center;
}

.close-btn {
  width: 100%;
  border: none;
  border-radius: 12px;
  padding: 0.72rem;
  background: #efe4d5;
  color: #5a4833;
  font-weight: 600;
  cursor: pointer;
}

.close-btn:hover {
  background: #e7d9c8;
}

.hidden {
  display: none;
}