body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "Segoe UI", sans-serif;
  background: #f5f5f7;
  color: #1d1d1f;
  -webkit-font-smoothing: antialiased;
}

body.dark {
  background: #000000;
  color: #f5f5f7;
}

body.dark .navbar {
  background: rgba(28, 28, 30, 0.9);
  border-bottom: 1px solid #2c2c2e;
}

body.dark .card,
body.dark .schedule-slot {
  background: #1c1c1e;
  box-shadow: none;
  margin: 8px;
}

body.dark input,
body.dark select {
  background: #2c2c2e;
  border: 1px solid #3a3a3c;
  color: #f5f5f7;
}

body.dark .navbar button {
  color: #f5f5f7;
}

body.dark .navbar button:hover {
  background: #2c2c2e;
}

body.dark .navbar button:hover {
  background: rgba(255, 255, 255, 0.08);
}


.container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.navbar {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid #e5e5e7;
  padding: 16px 50px;
  display: flex;
  align-items: center;
  justify-content: space-around;
  position: sticky;
  top: 0;
  z-index: 1000;
  gap: 10px;
  flex-wrap: wrap;
}

.navbar h2 {
  margin: 0;
  font-weight: 600;
  font-size: 18px;
  letter-spacing: -0.3px;
}

.navbar button {
  background: none;
  border: none;
  padding: 8px 16px;
  font-size: 14px;
  border-radius: 20px;
  cursor: pointer;
  color: #1d1d1f;
  transition: background 0.2s ease, color 0.2s ease;
}

.navbar button:hover {
  background: #f2f2f2;
}

.main {
  padding: 50px 80px;
  flex: 1;
}

.section {
  display: none;
}

.section.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

h1 {
  font-weight: 600;
  letter-spacing: -0.5px;
}

h3 {
  color: #6e6e73;
  font-weight: 500;
  margin-top: 30px;
}

.cards {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.card {
  background: #ffffff;
  border-radius: 18px;
  padding: 25px;
  margin: 8px;
  flex: 1;
  min-width: 220px;
  box-shadow:
    0 4px 12px rgba(0, 0, 0, 0.04),
    0 1px 2px rgba(0, 0, 0, 0.03);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow:
    0 10px 25px rgba(0, 0, 0, 0.08),
    0 3px 6px rgba(0, 0, 0, 0.05);
}

input,
select {
  padding: 10px 14px;
  margin: 8px 8px 8px 0;
  border-radius: 12px;
  border: 1px solid #e5e5e7;
  font-size: 14px;
  background: #ffffff;
  transition: border 0.2s ease;
}

input:focus,
select:focus {
  outline: none;
  border-color: #0071e3;
}

button {
  padding: 10px 18px;
  border-radius: 20px;
  border: none;
  cursor: pointer;
  font-size: 14px;
  background: #0071e3;
  color: white;
  transition: background 0.2s ease, transform 0.1s ease;
}

button:hover {
  background: #005bb5;
}

button:active {
  transform: scale(0.96);
}

.progress-bar-container {
  width: 100%;
  background: #e5e5ea;
  height: 10px;
  border-radius: 20px;
  margin: 10px 0;
}

.progress-bar {
  height: 100%;
  background: #0071e3;
  width: 0%;
  border-radius: 20px;
  transition: width 0.3s ease;
}

.subject-bar {
  background: #e5e5ea;
  height: 8px;
  border-radius: 20px;
  margin: 6px 0;
}

.subject-progress {
  height: 100%;
  background: #0071e3;
  border-radius: 20px;
  transition: width 0.3s ease;
}

.day-group {
  margin-bottom: 35px;
}

.schedule-slot {
  background: #ffffff;
  padding: 14px 18px;
  margin: 8px 0;
  border-radius: 14px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.04);
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: 0.2s ease;
}

.schedule-slot:hover {
  transform: translateY(-2px);
}

.overdue {
  border-left: 4px solid #ff3b30;
}

.toast {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: #1d1d1f;
  color: white;
  padding: 14px 20px;
  border-radius: 18px;
  font-size: 14px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from {opacity: 0; transform: translateY(10px);}
  to {opacity: 1; transform: translateY(0);}
}