:root {
  --primary: #3a86ff;
  --primary-dark: #2667cc;
  --text: #2b2d42;
  --text-light: #8d99ae;
  --background: #f8f9fa;
  --card-bg: #ffffff;
  --border: #e9ecef;
}

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

body {
  font-family: 'Inter', sans-serif;
  color: var(--text);
  background-color: var(--background);
  line-height: 1.6;
  padding: 20px;
  max-width: 1200px;
  margin: 0 auto;
}

.header {
  text-align: center;
  margin-bottom: 40px;
}

.header h1 {
  font-size: 2.5rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--primary);
}

.nav {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 30px;
}

.nav-btn {
  padding: 10px 20px;
  background: none;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.nav-btn:hover {
  background-color: rgba(58, 134, 255, 0.1);
}

.nav-btn.active {
  background-color: var(--primary);
  color: white;
}

.section {
  display: none;
}

.section.active {
  display: block;
}

.calculator-card, .workout-editor {
  background-color: var(--card-bg);
  border-radius: 10px;
  padding: 25px;
  margin-bottom: 20px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.calculator-card h2, .workout-editor h2 {
  margin-bottom: 20px;
  font-size: 1.5rem;
  color: var(--primary);
}

.input-group {
  margin-bottom: 15px;
}

.input-group label {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
}

.input-group input, .input-group select {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
}

button {
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: 6px;
  padding: 10px 20px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

button:hover {
  background-color: var(--primary-dark);
}

.result {
  margin-top: 15px;
  padding: 15px;
  background-color: rgba(58, 134, 255, 0.1);
  border-radius: 6px;
  font-weight: 500;
}

.workout-controls {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.workout-day {
  background-color: var(--card-bg);
  border-radius: 8px;
  padding: 15px;
  margin-bottom: 15px;
  border: 1px solid var(--border);
}

.workout-day h3 {
  margin-bottom: 10px;
}

.exercise {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
  padding: 10px;
  background-color: var(--background);
  border-radius: 6px;
}

.exercise input {
  flex: 1;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
}

.remove-btn {
  background-color: #ff3a3a;
  padding: 8px 12px;
}

.add-exercise-btn {
  background-color: #4caf50;
  margin-top: 5px;
}