/* Top Xisobot Education Design System Tokens & Styles */
:root {
  --brand-primary: #E53935;
  --brand-primary-dark: #C62828;
  --brand-accent: #4F6BFF;
  --bg-main: #F5F6F8;
  --surface: #FFFFFF;
  --surface-alt: #F0F2F5;
  --text-primary: #17181C;
  --text-secondary: #6B7280;
  --border: #E4E7EC;
  --success: #1F9D62;
  --warning: #E59A16;
  --danger: #D92D20;
  --info: #2563EB;

  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --control-height: 44px;
  --sidebar-width: 264px;
  --max-content-width: 1440px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
}

[data-theme="dark"] {
  --bg-main: #0F1115;
  --surface: #191C22;
  --surface-alt: #22262E;
  --text-primary: #F5F7FA;
  --text-secondary: #AAB1BD;
  --border: #303641;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.5;
  font-size: 15px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4 {
  font-weight: 600;
  color: var(--text-primary);
}
h1 { font-size: 26px; line-height: 1.3; }
h2 { font-size: 20px; line-height: 1.3; }
h3 { font-size: 17px; }
p { color: var(--text-secondary); }
small { font-size: 12px; color: var(--text-secondary); }

/* Layout Shell */
.app-container {
  display: flex;
  height: 100vh;
  overflow: hidden;
  position: relative;
}

.sidebar {
  width: var(--sidebar-width);
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  z-index: 40;
  transition: transform 0.2s ease-out;
}

.sidebar-header {
  padding: 18px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border);
}

.brand-badge {
  background: var(--brand-primary);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
  border: none;
  background: transparent;
  width: 100%;
  text-align: left;
  transition: background 0.15s, color 0.15s;
}

.nav-item:hover {
  background: var(--surface-alt);
  color: var(--text-primary);
}

.nav-item.active {
  background: rgba(229, 57, 53, 0.08);
  color: var(--brand-primary);
  font-weight: 600;
}

.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-main);
}

.topbar {
  height: 60px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  flex-shrink: 0;
  z-index: 30;
}

.content-body {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  max-width: var(--max-content-width);
  margin: 0 auto;
  width: 100%;
}

/* Cards & Panels */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.grid-cols-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.grid-cols-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.grid-cols-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }

/* Stat Widgets */
.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-label {
  font-size: 13px;
  color: var(--text-secondary);
}

/* Buttons & Inputs */
.btn {
  height: var(--control-height);
  min-width: 44px;
  padding: 0 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.15s ease-out;
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--brand-primary);
  color: #fff;
}
.btn-primary:hover:not(:disabled) {
  background: var(--brand-primary-dark);
}

.btn-outline {
  background: transparent;
  border-color: var(--border);
  color: var(--text-primary);
}
.btn-outline:hover:not(:disabled) {
  background: var(--surface-alt);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}

.btn-sm {
  height: 32px;
  padding: 0 10px;
  font-size: 12px;
  border-radius: 8px;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}

.input-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
}

.form-control {
  height: var(--control-height);
  padding: 0 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: border-color 0.15s;
  width: 100%;
}

.form-control:focus {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px rgba(229, 57, 53, 0.15);
}

/* Badges & Status */
.badge {
  padding: 4px 8px;
  border-radius: var(--radius-pill);
  font-size: 11px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.badge-success { background: rgba(31, 157, 98, 0.12); color: var(--success); }
.badge-warning { background: rgba(229, 154, 22, 0.12); color: var(--warning); }
.badge-danger { background: rgba(217, 45, 32, 0.12); color: var(--danger); }
.badge-info { background: rgba(79, 107, 255, 0.12); color: var(--brand-accent); }
.badge-secondary { background: var(--surface-alt); color: var(--text-secondary); }

/* Table */
.table-container {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 14px;
}

th {
  background: var(--surface-alt);
  padding: 12px 16px;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: rgba(0, 0, 0, 0.015); }

/* Modal */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
  backdrop-filter: blur(2px);
}

.modal-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  max-width: 540px;
  width: 100%;
  padding: 24px;
  box-shadow: var(--shadow-md);
  max-height: 90vh;
  overflow-y: auto;
}

/* Mobile Bottom Navigation */
.bottom-nav {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 56px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  z-index: 50;
  justify-content: space-around;
  align-items: center;
  padding-bottom: env(safe-area-inset-bottom);
}

.bottom-nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
  height: 100%;
  color: var(--text-secondary);
  font-size: 10px;
  font-weight: 500;
  text-decoration: none;
  gap: 2px;
}

.bottom-nav-item.active {
  color: var(--brand-primary);
  font-weight: 600;
}

/* Responsive Media Queries */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .bottom-nav {
    display: flex;
  }
  .content-body {
    padding: 16px;
    padding-bottom: 76px;
  }
  .grid-cols-2, .grid-cols-3, .grid-cols-4 {
    grid-template-columns: 1fr;
  }
}