* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  background: #0f172a;
  color: white;
}

body.light {
  background: #f1f5f9;
  color: #0f172a;
}

/* LAYOUT */
.container {
  display: flex;
  min-height: 100vh;
}

/* SIDEBAR */
.sidebar {
  width: 250px;
  background: #020617;
  padding: 30px 20px;
}

.logo {
  text-align: center;
  margin-bottom: 30px;
  color: #38bdf8;
}

.sidebar ul li {
  list-style: none;
  padding: 15px;
  margin: 10px 0;
  cursor: pointer;
  border-radius: 10px;
}

.sidebar ul li:hover,
.sidebar ul .active {
  background: linear-gradient(135deg, #38bdf8, #0ea5e9);
}

.toggle-btn {
  margin-top: 20px;
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
}

/* MAIN */
.main {
  flex: 1;
  padding: 30px;
}

/* SECTIONS */
.section {
  display: none;
}

.section.active {
  display: block;
}

/* CARDS */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px,1fr));
  gap: 20px;
  margin: 20px 0;
}

.card {
  background: rgba(255,255,255,0.1);
  padding: 20px;
  border-radius: 15px;
  text-align: center;
}

.card p {
  font-size: 30px;
  color: #38bdf8;
}

/* CHART */
.chart-box {
  margin-top: 30px;
  background: rgba(255,255,255,0.08);
  padding: 20px;
  border-radius: 15px;
}

/* COURSES */
.course-list li {
  margin: 10px 0;
  padding: 10px;
  background: rgba(255,255,255,0.1);
  border-radius: 10px;
}