:root {
  --bg-main: #f0f9ff;
  /* Light Sky Tint */
  --accent: #0ea5e9;
  /* Sky Blue */
  --accent-soft: #e0f2fe;
  --text-main: #334155;
  /* Slate Gray */
  --text-soft: #64748b;
  --card-shadow: 0 10px 30px -5px rgba(14, 165, 233, 0.1);
  --header-font: 'Outfit', sans-serif;
}

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

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: 'Inter', -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.container {
  max-width: 600px;
  width: 100%;
  padding: 2rem 1.5rem;
}

.hero {
  text-align: center;
  margin-bottom: 2rem;
}

h1 {
  font-family: var(--header-font);
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.02em;
  margin-bottom: 0.2rem;
}

.hero p {
  font-size: 1rem;
  color: var(--text-soft);
}

.card {
  background: white;
  border-radius: 24px;
  padding: 2rem;
  box-shadow: var(--card-shadow);
  border: 1px solid #e0f2fe;
  margin-bottom: 2rem;
}

.input-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-soft);
  margin-bottom: 0.5rem;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  height: 6px;
  border-radius: 3px;
  background: #f1f5f9;
}

select {
  width: 100%;
  padding: 0.8rem 1rem;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
  background: #f8fafc;
  font-size: 1rem;
  color: var(--text-main);
  cursor: pointer;
  outline: none;
  transition: all 0.2s;
}

select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1);
}

.price-box {
  text-align: center;
  padding-top: 1.5rem;
  margin-top: 1.5rem;
  border-top: 2px solid #f0f9ff;
}

.price-value {
  font-size: 4rem;
  font-weight: 800;
  color: var(--accent);
  font-family: var(--header-font);
}

.price-unit {
  font-size: 0.75rem;
  color: var(--text-soft);
  font-weight: 700;
  letter-spacing: 0.1em;
}

.bundle-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

.bundle-card {
  padding: 1.25rem;
  border-radius: 16px;
  border: 2px solid #f1f5f9;
  cursor: pointer;
  transition: all 0.2s ease;
  background: white;
  text-align: center;
}

.bundle-card.active {
  border-color: var(--accent);
  background-color: var(--accent-soft);
}

.bundle-card h3 {
  font-size: 1.1rem;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.bundle-card p {
  font-size: 0.75rem;
  color: var(--text-soft);
  line-height: 1.3;
}

.btn {
  display: block;
  width: 100%;
  padding: 1.1rem;
  background-color: var(--accent);
  color: white;
  border: none;
  border-radius: 16px;
  font-weight: 700;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  cursor: pointer;
  margin-top: 1.5rem;
  box-shadow: 0 4px 14px 0 rgba(14, 165, 233, 0.39);
  transition: all 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(14, 165, 233, 0.23);
}

.btn:active {
  transform: scale(0.98);
}

footer {
  text-align: center;
  margin-top: 3rem;
  color: var(--text-soft);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}