:root {
  --bg-color: #f8f9fa;
  --container-bg: #ffffff;
  --text-color: #2d3436;
  --border-color: #dfe6e9;
  --accent-color: #0984e3;
  --header-bg: #ffffff;
  --hover-color: #f1f2f6;
  --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

body.dark-mode {
  --bg-color: #1a1a1b;
  --container-bg: #2d2d2e;
  --text-color: #e4e6eb;
  --border-color: #3e4042;
  --accent-color: #74b9ff;
  --header-bg: #2d2d2e;
  --hover-color: #3a3b3c;
  --shadow: 0 4px 6px rgba(0,0,0,0.3);
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

header {
  background-color: var(--header-bg);
  padding: 1rem 2rem;
  box-shadow: var(--shadow);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 10;
}

h1 { margin: 0; font-size: 1.5rem; }

.controls {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

#current-date {
  font-weight: 500;
  color: var(--accent-color);
}

button {
  background-color: var(--accent-color);
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 500;
  transition: opacity 0.2s;
}

button:hover { opacity: 0.9; }

main {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 2rem;
}

.attendance-container {
  background-color: var(--container-bg);
  width: 100%;
  max-width: 600px;
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 1.5rem;
  height: fit-content;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
}

th {
  text-align: left;
  padding: 12px;
  border-bottom: 2px solid var(--border-color);
  color: var(--accent-color);
}

td {
  padding: 12px;
  border-bottom: 1px solid var(--border-color);
}

tr:hover {
  background-color: var(--hover-color);
}

.stats {
  display: flex;
  justify-content: space-around;
  padding-top: 1rem;
  border-top: 2px solid var(--border-color);
  font-weight: 600;
}

/* Custom Checkbox Styling */
input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--accent-color);
}