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

:root {
  --bg: #f5f0eb;
  --card: #ffffff;
  --primary: #4a2c2a;
  --accent: #8b5e3c;
  --text: #2c1810;
  --muted: #7a6a63;
  --error: #c0392b;
  --radius: 12px;
  --shadow: 0 2px 8px rgba(74, 44, 42, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100dvh;
  padding: 1rem;
}

.container {
  max-width: 420px;
  margin: 0 auto;
  padding-bottom: 2rem;
}

header {
  text-align: center;
  padding: 1.5rem 0 1rem;
}

header h1 {
  font-size: 2rem;
  color: var(--primary);
}

.subtitle {
  color: var(--muted);
  font-size: 0.95rem;
  margin-top: 0.25rem;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
  margin-top: 1rem;
}

.card h2 {
  font-size: 1rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.input-group label {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-align: center;
  cursor: pointer;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  border-radius: 4px;
  background: linear-gradient(to right, var(--accent), var(--primary));
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

input[type="range"]::-moz-range-thumb {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.number-input {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.number-input input[type="number"] {
  width: 80px;
  padding: 0.5rem;
  font-size: 1.1rem;
  text-align: center;
  border: 2px solid var(--accent);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
}

.number-input input[type="number"]:focus {
  outline: none;
  border-color: var(--primary);
}

.number-input span {
  color: var(--muted);
  font-size: 0.95rem;
}

.water-display {
  text-align: center;
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary);
}

.water-display span:last-child {
  font-size: 1.2rem;
  color: var(--muted);
  font-weight: 400;
}

.split-result {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1rem;
}

.pour-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  background: var(--bg);
  border-radius: 8px;
}

.pour-item span:first-child {
  color: var(--muted);
}

.pour-item span:last-child {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.error {
  color: var(--error);
  font-size: 0.85rem;
  text-align: center;
  min-height: 1.2em;
}

.btn-split {
  display: block;
  width: 100%;
  margin-top: 1rem;
  padding: 1rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: background 0.2s;
}

.btn-split:hover {
  background: var(--primary);
}

.btn-split.active {
  background: var(--primary);
}

/* Hide number input spin buttons for cleaner look */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

input[type="number"] {
  -moz-appearance: textfield;
}