:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;

  --bg-page: #f3f4f6;
  --bg-card: #ffffff;
  --bg-muted: #fafafa;
  --bg-muted-2: #f0f0f0;

  --border-radius: 12px;
  --border-radius-sm: 8px;

  --shadow-card: 0 4px 18px rgba(0,0,0,0.1);

  --text-muted: #555;
  --border-default: #d1d5db;
}



* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: var(--bg-page);
}

h1, h2, h3 {
  margin-top: 0;
  text-align: center;
}



header {
  background-color: #007bff;
  color: #fff;
  padding: 15px 20px;
  text-align: center;
  font-size: 18px;
  font-weight: bold;
}

header a {
  color: inherit;
  text-decoration: none;
  margin: 0 10px;
}

header a:hover {
  text-decoration: underline;
}



.card {
  background: var(--bg-card);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-card);
}

.form-container {
  max-width: 400px;
  margin: 40px auto;
}

.table-container,
.chart-container {
  max-width: 900px;
  margin: 40px auto;
}

.chart-container {
  width: 100%;
}



.info-box {
  background: var(--primary-light);
  padding: 10px 15px;
  border-left: 4px solid var(--primary);
  border-radius: var(--border-radius-sm);
  margin-bottom: 20px;
}

.data-status {
  font-size: 0.85rem;
  background: #f6f6f6;
  border-left: 4px solid #4caf50;
  padding: 8px 12px;
  margin: 10px 0 16px;
  max-width: 520px;
}

.data-status strong {
  display: block;
  margin-bottom: 4px;
}



table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 15px;
}

th {
  background: #e5e7eb;
  padding: 8px;
  text-align: center;
  font-weight: bold;
}

td {
  padding: 8px;
  background: var(--bg-muted);
}

tr:nth-child(even) td {
  background: var(--bg-muted-2);
}



.activity-table th,
.activity-table td {
  padding: 6px 10px;
  font-size: 14px;
  border-bottom: 1px solid #eee;
}

.activity-table tr.week-separator td {
  border-top: 2px solid #444;
}

.activity-table tr.weekend {
  background: #f8f8f8;
}



.skinfold-section {
  background: #fef9c3;
  border: 1px solid #fde047;
  padding: 10px;
  border-radius: 10px;
  margin-top: 20px;
}

.muscle-group-section {
  background: var(--bg-page);
  padding: 15px;
  margin-bottom: 20px;
  border-radius: 10px;
  border: 1px solid var(--border-default);
}

.muscle-group-section.single-muscle {
  background: #fff4e6;
  border-color: #fcd34d;
}



input[type="number"],
input[type="date"],
select {
  width: 100%;
  padding: 6px 8px;
  border-radius: 6px;
  border: 1px solid #ccc;
}

.submit-btn {
  margin-top: 20px;
  width: 100%;
  padding: 12px;
  background: var(--primary);
  color: #fff;
  font-size: 16px;
  border: none;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
}

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



.switch {
  position: relative;
  width: 45px;
  height: 24px;
  display: inline-block;
}

.switch input {
  opacity: 0;
}

.slider {
  position: absolute;
  inset: 0;
  background: #ccc;
  border-radius: 24px;
  transition: .4s;
  cursor: pointer;
}

.slider::before {
  content: "";
  position: absolute;
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background: #fff;
  border-radius: 50%;
  transition: .4s;
}

input:checked + .slider {
  background: var(--primary);
}

input:checked + .slider::before {
  transform: translateX(21px);
}



.layout {
  display: grid;
  grid-template-columns: 400px 1fr;
  gap: 40px;
  max-width: 1600px;
  margin: 0 auto;
  padding: 20px;
  align-items: start;
}

.right-column {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

@media (max-width: 1100px) {
  .layout {
    grid-template-columns: 1fr;
  }
}