* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-top: #0f172a;
  --bg-bottom: #1e1b4b;
  --accent: #6366f1;
  --accent-2: #a78bfa;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --card: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.12);
  --danger: #fb7185;
}

body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--bg-top), var(--bg-bottom));
  color: var(--text);
  padding: 1.5rem;
}

.app {
  width: 100%;
  max-width: 560px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 1.5rem;
  padding: 2.5rem 2rem;
  backdrop-filter: blur(12px);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.4);
}

.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-2);
  background: rgba(167, 139, 250, 0.12);
  border: 1px solid rgba(167, 139, 250, 0.25);
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  margin-bottom: 1.1rem;
}

.header h1 {
  font-size: clamp(1.6rem, 4.5vw, 2.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.header p {
  color: var(--muted);
  margin-top: 0.5rem;
  font-size: 0.95rem;
  line-height: 1.5;
}

.form {
  margin-top: 1.8rem;
}

.form label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.input-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.input-row input {
  flex: 1;
  min-width: 180px;
  padding: 0.8rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.input-row input::-webkit-calendar-picker-indicator {
  filter: invert(1);
  cursor: pointer;
}

.input-row input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
}

.btn {
  padding: 0.8rem 1.6rem;
  font-size: 1rem;
  font-weight: 700;
  font-family: inherit;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border: none;
  border-radius: 0.75rem;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s;
  box-shadow: 0 8px 24px rgba(99, 102, 241, 0.4);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(99, 102, 241, 0.5);
}

.btn:active {
  transform: translateY(0);
}

.error {
  margin-top: 0.9rem;
  color: var(--danger);
  font-size: 0.88rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.result {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.9rem;
  margin-top: 2rem;
  animation: fade-up 0.5s ease;
}

.stat {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 1.2rem 0.6rem;
  text-align: center;
}

.stat-value {
  display: block;
  font-size: clamp(1.8rem, 6vw, 2.4rem);
  font-weight: 800;
  color: var(--accent-2);
  line-height: 1;
}

.stat-label {
  display: block;
  margin-top: 0.45rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.extra {
  margin-top: 1.4rem;
  animation: fade-up 0.5s ease;
}

.extra-line {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.6;
}

.extra-line span {
  color: var(--text);
  font-weight: 600;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 480px) {
  .card {
    padding: 1.8rem 1.2rem;
  }
  .input-row {
    flex-direction: column;
  }
  .input-row input,
  .btn {
    width: 100%;
  }
}