:root {
  --bg-color: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #0ea5e9;
  --danger: #ef4444;
  --input-bg: rgba(15, 23, 42, 0.6);
  --border: rgba(255, 255, 255, 0.1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
}

.blob-1 {
  top: -10%;
  left: -10%;
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, #3b82f6, #8b5cf6);
  animation: move1 20s infinite alternate;
}

.blob-2 {
  bottom: -10%;
  right: -10%;
  width: 40vw;
  height: 40vw;
  background: radial-gradient(circle, #ec4899, #f43f5e);
  animation: move2 15s infinite alternate;
}

@keyframes move1 {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(10%, 20%) scale(1.1); }
}

@keyframes move2 {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-10%, -20%) scale(1.2); }
}

.calculator-container {
  position: relative;
  z-index: 1;
  background: var(--card-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 48px;
  width: 100%;
  max-width: 500px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  animation: slideUp 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

h1 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 8px;
  text-align: center;
  background: linear-gradient(to right, #38bdf8, #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 32px;
  line-height: 1.5;
}

.input-group {
  margin-bottom: 20px;
}

.input-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.input-group input {
  width: 100%;
  padding: 16px;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text-primary);
  font-size: 16px;
  outline: none;
  transition: all 0.3s ease;
}

.input-group input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.1);
}

/* Hide number input spinners */
.input-group input::-webkit-outer-spin-button,
.input-group input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.input-group input[type=number] {
  -moz-appearance: textfield;
}

.actions {
  display: flex;
  gap: 16px;
  margin-top: 32px;
}

button {
  flex: 1;
  padding: 16px;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
}

.primary-btn {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 14px 0 rgba(56, 189, 248, 0.39);
}

.primary-btn:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.4);
}

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

.secondary-btn {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.secondary-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.error-message {
  margin-top: 16px;
  color: var(--danger);
  font-size: 14px;
  text-align: center;
  min-height: 20px;
}

@media (max-width: 600px) {
  .calculator-container {
    margin: 16px;
    padding: 32px 24px;
  }
}