:root {
  --font-family: Inter, sans-serif;
  --color-page-bg: #F5F6FA;
  --color-primary: #1A73E8;
  --color-primary-dark: #155FCC;
  --color-primary-light: #E8F1FF;
  --color-success: #28C76F;
  --color-success-light: #E9FCEF;
  --color-warning: #FFCE3A;
  --color-warning-light: #FFF8E2;
  --color-danger: #EA5455;
  --color-danger-light: #FFECEC;
  --color-heading: #1A1A1A;
  --color-subheading: #4A4A4A;
  --color-body: #6E6E6E;
  --color-muted: #9A9A9A;
  --color-white: #FFFFFF;
  --color-gray-100: #F5F6FA;
  --color-gray-200: #ECECEC;
  --color-gray-300: #E1E1E1;
  --color-gray-400: #C8C8C8;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-round: 999px;
  --shadow-card: 0 2px 10px rgba(0,0,0,0.06);
  --shadow-menu: 0 4px 14px rgba(0,0,0,0.09);
  --shadow-button: 0 2px 6px rgba(26, 115, 232, 0.25);
  --table-header-bg: #FFFFFF;
  --table-row-bg: #FFFFFF;
  --table-row-border: #ECECEC;
  --table-row-hover: #F5F6FA;
  --panel-dark-gradient: linear-gradient(135deg, #1A2C90 0%, #0F1C5C 100%);
  --panel-dark-heading: #FFFFFF;
  --panel-dark-subtext: #C8D4FF;
  --focus-outline: 2px solid #1A73E8;
  --hover-transition: 150ms;
  --hover-scale: 1.01;
  --pressed-scale: 0.97;
  --card-padding: 20px;
  --section-gap: 24px;
  --size-sm: 14px;
  --size-md: 16px;
  --size-lg: 18px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; min-height: 100%; }
body {
  font-family: var(--font-family);
  background: var(--color-page-bg);
  color: var(--color-body);
  line-height: 1.4;
}
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-dark); }

.app-shell { display: grid; grid-template-columns: 274px 1fr; min-height: 100vh; }
.sidebar {
  background: var(--color-white);
  border-right: 1px solid var(--color-gray-200);
  padding: 20px 16px;
  transition: transform 180ms ease, width 180ms ease, padding 180ms ease;
  z-index: 40;
}
.sidebar-guide {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.brand-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 10px 14px;
  border-bottom: 1px solid var(--color-gray-200);
}
.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-white);
  display: grid;
  place-items: center;
  font-weight: 700;
}
.brand-copy {
  color: var(--color-heading);
  font-size: var(--size-lg);
  font-weight: 700;
}
.nav-section {
  margin: 10px 12px 4px;
  font-size: var(--size-xs, 12px);
  color: var(--color-muted);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.nav-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.nav-item,
.sidebar a {
  display: block;
  padding: 11px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-subheading);
  font-size: var(--size-lg);
  font-weight: 500;
}
.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
}
.nav-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 18px;
  overflow: hidden;
}
.nav-icon svg {
  width: 18px !important;
  height: 18px !important;
  min-width: 18px;
  min-height: 18px;
  max-width: 18px;
  max-height: 18px;
  display: block;
}
.nav-item.active,
.nav-item:hover,
.sidebar a.active,
.sidebar a:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
}
.sidebar-user {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  border-radius: var(--radius-md);
  background: var(--color-gray-100);
}
.sidebar-user-avatar {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-round);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  display: grid;
  place-items: center;
}
.sidebar-user-name {
  color: var(--color-heading);
  font-weight: 700;
}
.sidebar-user-role {
  color: var(--color-body);
  font-size: 12px;
  text-transform: capitalize;
}
.sidebar-logout {
  margin-top: 8px;
}
.sidebar-backdrop {
  display: none;
}

body.sidebar-collapsed .app-shell {
  grid-template-columns: 88px 1fr;
}
body.sidebar-collapsed .sidebar {
  padding: 20px 10px;
}
body.sidebar-collapsed .brand-wrap {
  justify-content: center;
}
body.sidebar-collapsed .brand-copy,
body.sidebar-collapsed .nav-section,
body.sidebar-collapsed .nav-item > span:last-child,
body.sidebar-collapsed .sidebar-user > div,
body.sidebar-collapsed .sidebar-logout {
  display: none;
}
body.sidebar-collapsed .nav-item,
body.sidebar-collapsed .sidebar-user {
  justify-content: center;
}

.main-shell {
  min-width: 0;
}
.topbar {
  height: 90px;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  padding: 12px 34px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.topbar-search-wrap {
  width: min(520px, 100%);
  position: relative;
}
.topbar-search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-muted);
  font-size: 18px;
}
.topbar-search {
  width: 100%;
  border: 1px solid var(--color-gray-200);
  background: var(--color-gray-100);
  border-radius: var(--radius-sm);
  height: 44px;
  padding: 0 12px 0 42px;
  font-size: var(--size-md);
  color: var(--color-subheading);
}
.topbar-search:focus {
  border-color: var(--color-primary);
  outline: var(--focus-outline);
  outline-offset: 1px;
}
.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.topbar-menu-btn {
  flex: 0 0 auto;
}
.topbar-icon-btn {
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-gray-200);
  background: var(--color-gray-100);
  color: var(--color-subheading);
  border-radius: var(--radius-sm);
  font-weight: 700;
  cursor: pointer;
}
.topbar-avatar {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-round);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  display: grid;
  place-items: center;
}
.main-content { padding: var(--section-gap); }
.main-content-guide {
  padding: 24px 34px 34px;
}

.navbar {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: 16px 20px;
  margin-bottom: var(--section-gap);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.03);
  padding: var(--card-padding);
}

.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 16px; }

.btn {
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 10px 16px;
  font-size: var(--size-sm);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--hover-transition), transform var(--hover-transition), color var(--hover-transition), border-color var(--hover-transition);
}
.btn:focus-visible { outline: var(--focus-outline); outline-offset: 2px; }
.btn:active { transform: scale(var(--pressed-scale)); }
.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: var(--shadow-button);
}
.btn-primary:hover { background: var(--color-primary-dark); transform: scale(var(--hover-scale)); }
.btn-secondary {
  background: var(--color-white);
  color: var(--color-primary);
  border-color: var(--color-gray-200);
}
.btn-secondary:hover { background: var(--color-gray-100); }
.btn-danger {
  background: var(--color-danger);
  color: var(--color-white);
}
.badge-soft-primary {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.input, .select, .textarea {
  width: 100%;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: var(--size-sm);
  background: var(--color-white);
  color: var(--color-subheading);
}
.input:focus, .select:focus, .textarea:focus {
  border-color: var(--color-primary);
  outline: var(--focus-outline);
  outline-offset: 1px;
}

.label {
  display: block;
  margin-bottom: 6px;
  color: var(--color-subheading);
  font-weight: 600;
  font-size: var(--size-sm);
}

.table {
  width: 100%;
  border-collapse: collapse;
  background: var(--table-row-bg);
  border: 1px solid var(--table-row-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.table th,
.table td {
  border-bottom: 1px solid var(--table-row-border);
  padding: 10px 12px;
  text-align: left;
  font-size: var(--size-sm);
}
.table th {
  background: var(--color-gray-100);
  color: var(--color-subheading);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  font-size: 12px;
}
.table tr:hover td { background: var(--table-row-hover); }
.table-guide td {
  vertical-align: middle;
}

.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: var(--radius-round);
  font-size: 12px;
  font-weight: 600;
}
.badge-success { background: var(--color-success-light); color: var(--color-success); }
.badge-warning { background: var(--color-warning-light); color: var(--color-warning); }
.badge-danger { background: var(--color-danger-light); color: var(--color-danger); }

.alert {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}
.alert-success { background: var(--color-success-light); color: var(--color-success); }
.alert-error { background: var(--color-danger-light); color: var(--color-danger); }

.page-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 18px;
}
.page-title {
  margin: 0;
  color: var(--color-heading);
  font-size: 24px;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.page-subtitle {
  margin: 6px 0 0;
  font-size: 12px;
  color: var(--color-subheading);
}
.page-head-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}
.stat-card {
  display: grid;
  gap: 10px;
}
.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
}
.stat-icon svg {
  width: 24px;
  height: 24px;
  display: block;
}
.stat-icon-warn { background: var(--color-warning-light); color: var(--color-warning); }
.stat-icon-success { background: var(--color-success-light); color: var(--color-success); }
.stat-icon-primary { background: var(--color-primary-light); color: var(--color-primary); }
.stat-label {
  color: var(--color-subheading);
  font-size: var(--size-md);
}
.stat-value {
  color: var(--color-heading);
  font-size: 42px;
  font-weight: 700;
  line-height: 1.1;
}

.data-card {
  padding: 0;
  overflow: hidden;
}
.data-card-head {
  padding: 18px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.section-title {
  color: var(--color-heading);
  margin: 0 0 8px;
}
.section-subtitle {
  margin: 0;
  color: var(--color-subheading);
}
.data-card-tools {
  display: flex;
  gap: 8px;
}
.data-card-foot {
  padding: 16px 20px;
  border-top: 1px solid var(--color-gray-200);
  display: flex;
  justify-content: space-between;
}

.profile-hero {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}
.profile-main {
  display: flex;
  align-items: center;
  gap: 16px;
}
.profile-avatar {
  width: 108px;
  height: 108px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-size: 44px;
  font-weight: 700;
  display: grid;
  place-items: center;
}
.profile-name {
  margin: 0;
  color: var(--color-heading);
  font-size: 32px;
  font-weight: bold;
}
.profile-meta-row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
  color: var(--color-subheading);
}
.profile-id {
  font-size: var(--size-md);
}
.profile-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.profile-grid {
  margin-top: 16px;
  display: grid;
  grid-template-columns: 1.7fr 1fr;
  gap: 16px;
}
.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}
.course-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}
.course-card {
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 14px;
  display: flex;
  gap: 10px;
  align-items: flex-start;
}
.course-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  display: grid;
  place-items: center;
}
.course-title {
  color: var(--color-heading);
  font-weight: 700;
  font-size: var(--size-lg);
}
.course-sub {
  color: var(--color-subheading);
  margin-top: 4px;
}
.course-time {
  color: var(--color-primary-dark);
  margin-top: 4px;
  font-weight: 600;
}
.contact-list {
  display: grid;
  gap: 12px;
}
.contact-item {
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-sm);
  padding: 12px;
  background: var(--color-gray-100);
}
.contact-item span {
  display: block;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 11px;
  color: var(--color-muted);
  margin-bottom: 4px;
  font-weight: 700;
}
.contact-item strong {
  color: var(--color-heading);
  font-size: var(--size-md);
}
.panel-dark {
  padding: 20px;
  border-radius: var(--radius-md);
  background: var(--panel-dark-gradient);
  color: var(--panel-dark-heading);
  box-shadow: var(--shadow-menu);
}
.panel-dark h3 {
  margin-top: 0;
  margin-bottom: 14px;
  color: var(--panel-dark-heading);
}
.milestone-card {
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin-bottom: 10px;
  background: rgba(255, 255, 255, 0.08);
}
.milestone-card span {
  display: block;
  color: var(--panel-dark-subtext);
  font-size: 11px;
  letter-spacing: 0.06em;
  font-weight: 700;
}
.milestone-card strong {
  display: block;
  margin: 6px 0 4px;
  color: var(--panel-dark-heading);
  font-size: var(--size-lg);
}
.milestone-card p {
  margin: 0;
  color: var(--panel-dark-subtext);
}

@media (max-width: 1024px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: 274px;
    border-right: 1px solid var(--color-gray-200);
    border-bottom: 0;
    transform: translateX(-100%);
    overflow-y: auto;
  }
  body.sidebar-open .sidebar {
    transform: translateX(0);
  }
  .sidebar-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(8, 16, 36, 0.45);
    opacity: 0;
    pointer-events: none;
    transition: opacity 180ms ease;
    z-index: 30;
  }
  body.sidebar-open .sidebar-backdrop {
    opacity: 1;
    pointer-events: auto;
  }
  body.sidebar-collapsed .app-shell {
    grid-template-columns: 1fr;
  }
  .main-content-guide { padding: 16px; }
  .topbar { padding: 10px 16px; height: auto; flex-wrap: wrap; }
  .topbar-search-wrap { width: 100%; }
  .grid-2, .grid-3, .stat-grid, .profile-grid, .course-grid { grid-template-columns: 1fr; }
  .profile-hero { flex-direction: column; align-items: flex-start; }
  .profile-main { flex-direction: column; align-items: flex-start; }
  .profile-actions { width: 100%; }
  .profile-actions .btn { width: 100%; text-align: center; }
  .page-head { flex-direction: column; }
  .page-title { font-size: 30px; }
  .page-subtitle { font-size: 20px; }
}

@media (max-width: 640px) {
  .sidebar-user { margin-top: 10px; }
  .brand-copy { font-size: 20px; }
}

/* Local utility classes used in views (replaces Tailwind CDN dependency). */
.inline-flex { display: inline-flex; }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-2 { gap: 0.5rem; }
.px-3 { padding-left: 0.75rem; padding-right: 0.75rem; }
.py-1 { padding-top: 0.25rem; padding-bottom: 0.25rem; }
.text-xs { font-size: 0.75rem; line-height: 1rem; }
.leading-none { line-height: 1; }