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

body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #1a1a2e, #16213e, #0f3460);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  overflow: hidden;
}

.card {
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 24px;
  padding: 48px 40px;
  text-align: center;
  max-width: 420px;
  width: 90%;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  color: #fff;
}

h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.subtitle {
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 28px;
  font-size: 0.95rem;
}

input[type="date"] {
  width: 100%;
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font-size: 1rem;
  margin-bottom: 16px;
  outline: none;
  transition: border 0.2s;
}

input[type="date"]:focus {
  border-color: rgba(255, 255, 255, 0.5);
}

input[type="date"]::-webkit-calendar-picker-indicator {
  filter: invert(1);
  cursor: pointer;
}

button {
  width: 100%;
  padding: 13px;
  border-radius: 12px;
  border: none;
  background: linear-gradient(135deg, #e94560, #f5a623);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.1s;
}

button:hover {
  opacity: 0.9;
}

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

.result {
  margin-top: 28px;
  padding: 20px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.result.hidden {
  display: none;
}

.result.birthday h2 {
  font-size: 1.6rem;
  color: #f5a623;
  margin-bottom: 8px;
}

.result.birthday p {
  color: rgba(255, 255, 255, 0.8);
  font-size: 0.95rem;
}

.result.countdown h2 {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 16px;
  font-weight: 400;
}

.countdown-boxes {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.box {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  padding: 12px 16px;
  min-width: 64px;
}

.box .num {
  font-size: 1.8rem;
  font-weight: 700;
  color: #e94560;
  line-height: 1;
}

.box .label {
  font-size: 0.7rem;
  color: rgba(255, 255, 255, 0.5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 4px;
}

.confetti-piece {
  position: fixed;
  width: 10px;
  height: 10px;
  top: -10px;
  border-radius: 2px;
  animation: fall linear forwards;
  pointer-events: none;
}

@keyframes fall {
  to {
    transform: translateY(110vh) rotate(720deg);
    opacity: 0;
  }
}