body {
  font-family: "Segoe UI", sans-serif;
  margin: 0;
  padding: 0;
  background: #f0f4f8;
  color: #2c3e50;
  display: flex;
  min-height: 100vh;
}

header {
  background: linear-gradient(135deg, #1e88e5, #1565c0);
  color: white;
  padding: 2rem;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  margin-bottom: 3rem;
}

header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 600;
}

header p {
  margin: 0.5rem 0 0;
  opacity: 0.9;
}

.container {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.card {
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  padding: 1.5rem;
  margin-bottom: 2rem;
  margin-left: 2rem;
  transition: all 0.2s ease;
  position: relative;
  z-index: 1;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.1);
}

.card h3 {
  color: #1e88e5;
  margin-top: 0;
  font-size: 1.25rem;
  border-bottom: 2px solid #e3f2fd;
  padding-bottom: 0.5rem;
}

.card canvas {
  max-width: 100%;
  height: auto;
}

.checkboxes {
  background: white;
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 2rem;
  margin-left: 2rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.checkboxes strong {
  display: block;
  margin-bottom: 0.5rem;
  color: #2c3e50;
}

.checkboxes label {
  background: #e3f2fd;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  margin: 0.25rem;
  display: inline-block;
  transition: all 0.2s ease;
}

.checkboxes label:hover {
  background: #bbdefb;
}

.checkboxes input[type="checkbox"] {
  margin-right: 0.5rem;
}

.sidebar {
  width: 250px;
  background: #1e88e5;
  color: white;
  padding: 1.5rem;
  position: fixed;
  height: 100vh;
  box-shadow: 2px 0 5px rgba(0,0,0,0.1);
  z-index: 1000;
}

.sidebar-header {
  text-align: center;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  margin-bottom: 1.5rem;
}

.sidebar-header h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
}

.datetime {
  background: rgba(255,255,255,0.1);
  padding: 1rem;
  border-radius: 8px;
  text-align: center;
  margin-bottom: 1.5rem;
}

.datetime #current-time {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.datetime #current-date {
  font-size: 1rem;
  opacity: 0.9;
}

.sidebar-menu {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar-menu li {
  margin-bottom: 0.5rem;
}

.sidebar-menu a {
  color: white;
  text-decoration: none;
  display: block;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  transition: background 0.3s ease;
}

.sidebar-menu a:hover {
  background: rgba(255,255,255,0.1);
}

.main-content {
  flex: 1;
  margin-left: 250px;
  padding: 2rem;
  position: relative;
  z-index: 1;
}

@media (max-width: 768px) {
  body {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
    padding: 1rem;
  }

  .sidebar-header {
    padding-bottom: 1rem;
    margin-bottom: 1rem;
  }

  .datetime {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
  }

  .datetime #current-time {
    font-size: 1.5rem;
    margin-bottom: 0;
  }

  .sidebar-menu {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
  }

  .sidebar-menu li {
    margin: 0;
  }

  .sidebar-menu a {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
  }

  .main-content {
    margin-left: 0;
    padding: 1rem;
  }

  header {
    padding: 1.5rem 1rem;
    margin-bottom: 2rem;
  }

  header h1 {
    font-size: 1.5rem;
  }

  .card {
    margin-left: 0;
    padding: 1rem;
  }

  .card canvas {
    height: 250px !important;
  }

  .checkboxes {
    margin-left: 0;
    padding: 0.75rem;
  }

  .checkboxes label {
    display: block;
    margin: 0.5rem 0;
    padding: 0.5rem;
  }

  canvas {
    height: 300px !important;
    width: 100% !important;
  }

  .card h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
  }
}

@media (max-width: 480px) {
  .datetime {
    flex-direction: column;
    text-align: center;
    gap: 0.5rem;
  }

  .datetime #current-time {
    font-size: 1.25rem;
  }

  .datetime #current-date {
    font-size: 0.9rem;
  }

  .sidebar-menu {
    flex-direction: column;
    align-items: stretch;
  }

  .sidebar-menu a {
    text-align: center;
  }

  header h1 {
    font-size: 1.25rem;
  }

  header p {
    font-size: 0.9rem;
  }

  .card {
    padding: 0.75rem;
  }

  .card canvas {
    height: 200px !important;
  }

  .card h3 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
  }
}