/**
 * College OS — Modern Student Dashboard & Portal Design System
 * Version: 2026.10.04
 */

:root {
  /* Color Tokens */
  --co-stu-bg: #f8fafc;
  --co-stu-bg-alt: #f1f5f9;
  --co-stu-surface: #ffffff;
  --co-stu-surface-hover: #f8fafc;
  --co-stu-border: #e2e8f0;
  --co-stu-border-light: #f1f5f9;
  
  --co-stu-primary: #4f46e5;
  --co-stu-primary-hover: #4338ca;
  --co-stu-primary-light: rgba(79, 70, 229, 0.08);
  --co-stu-primary-gradient: linear-gradient(135deg, #4f46e5 0%, #3b82f6 100%);
  
  --co-stu-secondary: #0ea5e9;
  --co-stu-accent-purple: #8b5cf6;
  --co-stu-success: #10b981;
  --co-stu-success-light: rgba(16, 185, 129, 0.1);
  --co-stu-warning: #f59e0b;
  --co-stu-warning-light: rgba(245, 158, 11, 0.1);
  --co-stu-danger: #ef4444;
  --co-stu-danger-light: rgba(239, 68, 68, 0.1);
  
  --co-stu-text: #0f172a;
  --co-stu-text-muted: #64748b;
  --co-stu-text-light: #94a3b8;
  
  --co-stu-shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.04), 0 1px 2px rgba(15, 23, 42, 0.02);
  --co-stu-shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.03);
  --co-stu-shadow-md: 0 10px 15px -3px rgba(15, 23, 42, 0.06), 0 4px 6px -4px rgba(15, 23, 42, 0.03);
  --co-stu-shadow-lg: 0 20px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.03);
  
  --co-stu-radius-sm: 8px;
  --co-stu-radius: 12px;
  --co-stu-radius-lg: 16px;
  --co-stu-radius-xl: 20px;
  
  --co-stu-sidebar-width: 260px;
  --co-stu-topbar-height: 64px;
  --co-stu-font: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

[data-theme-mode="dark"] {
  --co-stu-bg: #0b0f19;
  --co-stu-bg-alt: #111827;
  --co-stu-surface: #131b2e;
  --co-stu-surface-hover: #1e293b;
  --co-stu-border: #1e293b;
  --co-stu-border-light: #182234;
  
  --co-stu-text: #f8fafc;
  --co-stu-text-muted: #94a3b8;
  --co-stu-text-light: #64748b;
  
  --co-stu-primary-light: rgba(99, 102, 241, 0.15);
  --co-stu-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --co-stu-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.35);
  --co-stu-shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
  --co-stu-shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.5);
}

/* Base Reset & Layout */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body,
body.student-portal {
  background-color: var(--co-stu-bg);
  color: var(--co-stu-text);
  font-family: var(--co-stu-font);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
}

.co-student-shell {
  display: flex;
  min-height: 100vh;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  position: relative;
  background-color: var(--co-stu-bg);
}

/* Backdrop */
.co-student-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 990;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.co-student-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

/* ==========================================================================
   SIDEBAR NAVIGATION
   ========================================================================== */
.co-student-sidebar {
  width: var(--co-stu-sidebar-width);
  background: var(--co-stu-surface);
  border-right: 1px solid var(--co-stu-border);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 1000;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.co-sidebar-brand {
  height: var(--co-stu-topbar-height);
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--co-stu-border);
}

.co-sidebar-brand .brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--co-stu-text);
  font-weight: 800;
  font-size: 1.1rem;
}

.co-sidebar-brand .brand-icon {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--co-stu-primary-gradient);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.co-sidebar-brand .brand-text span {
  color: var(--co-stu-primary);
}

.co-sidebar-close {
  display: none;
  background: none;
  border: none;
  color: var(--co-stu-text-muted);
  font-size: 1.25rem;
  cursor: pointer;
  padding: 4px;
}

.co-sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.co-sidebar-nav .nav-section-title {
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--co-stu-text-light);
  padding: 0.75rem 0.75rem 0.25rem;
}

.co-sidebar-nav .nav-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.75rem;
  border-radius: var(--co-stu-radius-sm);
  color: var(--co-stu-text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.88rem;
  transition: all 0.18s ease;
}

.co-sidebar-nav .nav-item i {
  font-size: 1rem;
  width: 20px;
  text-align: center;
  color: var(--co-stu-text-light);
}

.co-sidebar-nav .nav-item:hover {
  background: var(--co-stu-surface-hover);
  color: var(--co-stu-text);
}

.co-sidebar-nav .nav-item:hover i {
  color: var(--co-stu-primary);
}

.co-sidebar-nav .nav-item.active {
  background: var(--co-stu-primary-light);
  color: var(--co-stu-primary);
  font-weight: 700;
}

.co-sidebar-nav .nav-item.active i {
  color: var(--co-stu-primary);
}

.co-sidebar-footer {
  padding: 0.75rem;
  border-top: 1px solid var(--co-stu-border);
  background: var(--co-stu-surface);
}

.sidebar-user-pill {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.5rem;
  border-radius: var(--co-stu-radius-sm);
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
}

.sidebar-user-pill .user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--co-stu-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8rem;
  flex-shrink: 0;
}

.sidebar-user-pill .user-info {
  flex: 1;
  min-width: 0;
}

.sidebar-user-pill .user-name {
  display: block;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--co-stu-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-user-pill .user-meta {
  display: block;
  font-size: 0.7rem;
  color: var(--co-stu-text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ==========================================================================
   MAIN CONTAINER & TOPBAR
   ========================================================================== */
.co-student-main {
  flex: 1;
  margin-left: var(--co-stu-sidebar-width);
  min-width: 0;
  max-width: calc(100vw - var(--co-stu-sidebar-width));
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.co-student-topbar {
  height: var(--co-stu-topbar-height);
  background: var(--co-stu-surface);
  border-bottom: 1px solid var(--co-stu-border);
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 800;
  width: 100%;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex: 1;
  min-width: 0;
  max-width: 480px;
}

.co-mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--co-stu-text);
  cursor: pointer;
  padding: 6px;
  border-radius: var(--co-stu-radius-sm);
}

.topbar-search {
  position: relative;
  width: 100%;
  display: flex;
  align-items: center;
}

.topbar-search .search-icon {
  position: absolute;
  left: 12px;
  color: var(--co-stu-text-light);
  font-size: 0.9rem;
}

.topbar-search input {
  width: 100%;
  height: 38px;
  padding: 0 54px 0 36px;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-sm);
  color: var(--co-stu-text);
  font-size: 0.85rem;
  font-family: inherit;
  outline: none;
  transition: all 0.18s ease;
}

.topbar-search input:focus {
  border-color: var(--co-stu-primary);
  background: var(--co-stu-surface);
  box-shadow: 0 0 0 3px var(--co-stu-primary-light);
}

.topbar-search .search-kbd {
  position: absolute;
  right: 10px;
  font-size: 0.65rem;
  font-weight: 700;
  padding: 2px 6px;
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: 4px;
  color: var(--co-stu-text-muted);
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.header-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.8rem;
}

.header-badge.streak-badge {
  background: var(--co-stu-warning-light);
  border: 1px solid rgba(245, 158, 11, 0.25);
  color: #d97706;
}

.header-badge.xp-badge {
  background: var(--co-stu-primary-light);
  border: 1px solid rgba(79, 70, 229, 0.25);
  color: var(--co-stu-primary);
}

.topbar-action-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--co-stu-radius-sm);
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  color: var(--co-stu-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.18s ease;
}

.topbar-action-btn:hover {
  background: var(--co-stu-surface-hover);
  color: var(--co-stu-text);
}

.topbar-profile {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 4px 10px 4px 4px;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: 999px;
  cursor: pointer;
  position: relative;
  transition: all 0.18s ease;
}

.topbar-profile:hover {
  border-color: var(--co-stu-primary);
}

.profile-avatar {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--co-stu-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.75rem;
}

.profile-meta {
  display: flex;
  flex-direction: column;
}

.profile-name {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--co-stu-text);
  line-height: 1.1;
}

.profile-role {
  font-size: 0.68rem;
  color: var(--co-stu-text-muted);
}

.co-profile-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: 220px;
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  box-shadow: var(--co-stu-shadow-lg);
  padding: 6px;
  display: none;
  flex-direction: column;
  gap: 2px;
  z-index: 1100;
}

.co-profile-dropdown.active {
  display: flex;
}

.dropdown-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--co-stu-radius-sm);
  color: var(--co-stu-text);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: background 0.15s ease;
}

.dropdown-link:hover {
  background: var(--co-stu-surface-hover);
}

.dropdown-link.text-danger {
  color: var(--co-stu-danger);
}

.dropdown-link.text-danger:hover {
  background: var(--co-stu-danger-light);
}

.dropdown-divider {
  height: 1px;
  background: var(--co-stu-border);
  margin: 4px 0;
}

/* ==========================================================================
   DASHBOARD CONTENT CANVAS
   ========================================================================== */
.co-dashboard-content {
  flex: 1;
  padding: 1.5rem;
  max-width: 1440px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.co-stu-hero {
  background: linear-gradient(135deg, #1e1b4b 0%, #312e81 50%, #4338ca 100%);
  border-radius: var(--co-stu-radius-xl);
  padding: 1.75rem 2rem;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 10px 25px -5px rgba(49, 46, 129, 0.3);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
}

.co-hero-content {
  position: relative;
  z-index: 2;
  flex: 1;
  min-width: 0;
}

.co-hero-greeting {
  font-size: 1.65rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.4rem;
}

.co-hero-subtitle {
  color: #c7d2fe;
  font-size: 0.95rem;
  max-width: 600px;
  margin-bottom: 1rem;
  line-height: 1.45;
}

.co-hero-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #e0e7ff;
}

.hero-pill.primary {
  background: rgba(99, 102, 241, 0.3);
  border-color: rgba(165, 180, 252, 0.4);
  color: #fff;
  font-weight: 700;
}

.co-hero-actions {
  display: flex;
  gap: 0.75rem;
  position: relative;
  z-index: 2;
  flex-shrink: 0;
}

.btn-stu.light {
  background: #ffffff;
  color: var(--co-stu-primary);
  font-weight: 700;
}

.btn-stu.light:hover {
  background: #f8fafc;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-stu.glass {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(8px);
}

.btn-stu.glass:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.co-kpi-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.co-kpi-card {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  padding: 1.25rem;
  box-shadow: var(--co-stu-shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.co-kpi-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.co-kpi-title {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--co-stu-text-muted);
}

.co-kpi-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
}

.co-kpi-icon.indigo { background: rgba(79, 70, 229, 0.1); color: #4f46e5; }
.co-kpi-icon.emerald { background: rgba(16, 185, 129, 0.1); color: #10b981; }
.co-kpi-icon.sky { background: rgba(14, 165, 233, 0.1); color: #0ea5e9; }
.co-kpi-icon.amber { background: rgba(245, 158, 11, 0.1); color: #f59e0b; }

.co-kpi-value {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--co-stu-text);
  line-height: 1.1;
}

.co-kpi-meta {
  font-size: 0.74rem;
  color: var(--co-stu-text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.co-kpi-progress {
  height: 6px;
  background: var(--co-stu-bg);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 4px;
}

.co-kpi-progress .bar {
  height: 100%;
  background: var(--co-stu-primary-gradient);
  border-radius: 999px;
  transition: width 0.4s ease;
}

.co-dashboard-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.85fr) minmax(300px, 1.15fr);
  gap: 1.5rem;
}

.co-main-column,
.co-side-column {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  min-width: 0;
}

.co-stu-card {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-lg);
  box-shadow: var(--co-stu-shadow-sm);
  overflow: hidden;
}

.co-card-header {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--co-stu-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.co-card-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--co-stu-text);
  display: flex;
  align-items: center;
  gap: 8px;
}

.co-card-action {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--co-stu-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 4px;
}

.co-card-action:hover {
  text-decoration: underline;
}

.co-card-body {
  padding: 1.25rem;
}

/* Enrolled Subjects Grid */
.co-subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}

.co-subject-card {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  padding: 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: all 0.18s ease;
}

.co-subject-card:hover {
  border-color: rgba(79, 70, 229, 0.4);
  transform: translateY(-2px);
  box-shadow: var(--co-stu-shadow);
}

.co-subject-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.co-subject-code {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--co-stu-primary);
  background: var(--co-stu-primary-light);
  padding: 2px 6px;
  border-radius: 4px;
}

.co-subject-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--co-stu-text);
  line-height: 1.3;
}

.co-subject-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--co-stu-text-muted);
}

.co-subject-actions {
  display: flex;
  gap: 6px;
  margin-top: auto;
  padding-top: 8px;
  border-top: 1px solid var(--co-stu-border-light);
}

/* Quick Action Center */
.co-quick-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
}

.co-quick-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.5rem;
  padding: 1rem 0.5rem;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  text-decoration: none;
  color: var(--co-stu-text);
  transition: all 0.18s ease;
}

.co-quick-item:hover {
  background: var(--co-stu-surface-hover);
  border-color: var(--co-stu-primary);
  transform: translateY(-2px);
  box-shadow: var(--co-stu-shadow-sm);
}

.co-quick-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.co-quick-label {
  font-size: 0.8rem;
  font-weight: 600;
}

.co-ai-card {
  background: linear-gradient(135deg, #312e81 0%, #4338ca 100%);
  border-radius: var(--co-stu-radius-lg);
  padding: 1.25rem;
  color: #fff;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.co-ai-title {
  font-size: 1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.co-ai-desc {
  font-size: 0.82rem;
  color: #c7d2fe;
  line-height: 1.4;
  margin: 0;
}

/* Recent Activity Stream */
.co-activity-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.co-activity-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 0.9rem;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-sm);
}

.co-activity-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.co-activity-text {
  flex: 1;
  min-width: 0;
}

.co-activity-title {
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--co-stu-text);
}

.co-activity-sub {
  font-size: 0.72rem;
  color: var(--co-stu-text-muted);
}

.co-activity-time {
  font-size: 0.72rem;
  color: var(--co-stu-text-light);
  white-space: nowrap;
}

/* Academic Scope Summary Card (Right Column) */
.co-scope-card {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.co-scope-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--co-stu-border-light);
  font-size: 0.82rem;
}

.co-scope-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.co-scope-label {
  color: var(--co-stu-text-muted);
  font-weight: 500;
}

.co-scope-value {
  color: var(--co-stu-text);
  font-weight: 700;
  text-align: right;
}

/* Buttons */
.btn-stu {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 0.6rem 1.1rem;
  border-radius: var(--co-stu-radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  border: 1px solid transparent;
  transition: all 0.18s ease;
}

.btn-stu.primary {
  background: var(--co-stu-primary);
  color: #fff;
  border-color: var(--co-stu-primary);
}

.btn-stu.primary:hover {
  background: var(--co-stu-primary-hover);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.btn-stu.secondary {
  background: var(--co-stu-surface);
  color: var(--co-stu-text);
  border-color: var(--co-stu-border);
}

.btn-stu.secondary:hover {
  background: var(--co-stu-surface-hover);
}

.btn-stu.success {
  background: var(--co-stu-success);
  color: #fff;
  border-color: var(--co-stu-success);
}

.btn-stu.success:hover {
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-stu.sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.78rem;
}

.btn-stu.lg {
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
}

/* ==========================================================================
   UNIFIED STUDENT PORTAL COMPONENT SUITE
   ========================================================================== */

/* Page Container */
.co-student-container {
  padding: 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 1440px;
  width: 100%;
  margin: 0 auto;
}

/* Breadcrumb */
.co-breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--co-stu-text-muted);
  font-weight: 600;
}

.co-breadcrumb a {
  color: var(--co-stu-text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.co-breadcrumb a:hover {
  color: var(--co-stu-primary);
}

.co-breadcrumb .separator {
  color: var(--co-stu-text-light);
  font-size: 0.7rem;
}

.co-breadcrumb .current {
  color: var(--co-stu-text);
}

/* Page Header */
.co-page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.co-page-header-title {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--co-stu-text);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.co-page-header-desc {
  font-size: 0.9rem;
  color: var(--co-stu-text-muted);
  margin-top: 0.3rem;
  max-width: 70ch;
  line-height: 1.45;
}

.co-page-header-actions {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

/* Filter Bar & Controls */
.co-filter-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.85rem;
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  padding: 0.85rem 1rem;
  box-shadow: var(--co-stu-shadow-sm);
  flex-wrap: wrap;
}

.co-filter-group {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
  flex: 1;
  min-width: 240px;
}

.co-search-box {
  position: relative;
  flex: 1;
  min-width: 200px;
  max-width: 380px;
}

.co-search-box i {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--co-stu-text-light);
  font-size: 0.85rem;
}

.co-search-input {
  width: 100%;
  height: 38px;
  padding: 0 12px 0 34px;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-sm);
  color: var(--co-stu-text);
  font-size: 0.85rem;
  font-family: inherit;
  outline: none;
  transition: all 0.18s ease;
}

.co-search-input:focus {
  border-color: var(--co-stu-primary);
  background: var(--co-stu-surface);
  box-shadow: 0 0 0 3px var(--co-stu-primary-light);
}

.co-filter-select {
  height: 38px;
  padding: 0 1rem 0 0.75rem;
  background: var(--co-stu-bg);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius-sm);
  color: var(--co-stu-text);
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 600;
  outline: none;
  cursor: pointer;
  transition: all 0.18s ease;
}

.co-filter-select:focus {
  border-color: var(--co-stu-primary);
}

/* Tabs */
.co-tab-row {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  overflow-x: auto;
  padding-bottom: 2px;
}

.co-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  color: var(--co-stu-text-muted);
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.18s ease;
  font-family: inherit;
}

.co-tab-btn:hover {
  background: var(--co-stu-surface-hover);
  color: var(--co-stu-text);
  border-color: var(--co-stu-border);
}

.co-tab-btn.active {
  background: var(--co-stu-primary);
  color: #fff;
  border-color: var(--co-stu-primary);
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.25);
}

/* Card Grid & Cards */
.co-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 1.25rem;
}

.co-card {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  padding: 1.25rem;
  box-shadow: var(--co-stu-shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.co-card:hover {
  transform: translateY(-2px);
  border-color: rgba(79, 70, 229, 0.3);
  box-shadow: var(--co-stu-shadow-md);
}

.co-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.75rem;
}

.co-card-icon-wrap {
  width: 42px;
  height: 42px;
  border-radius: var(--co-stu-radius-sm);
  background: var(--co-stu-primary-light);
  color: var(--co-stu-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  flex-shrink: 0;
}

.co-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--co-stu-text);
  line-height: 1.35;
  margin: 0;
}

.co-card-desc {
  font-size: 0.84rem;
  color: var(--co-stu-text-muted);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.co-card-meta {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-wrap: wrap;
  font-size: 0.78rem;
  color: var(--co-stu-text-muted);
}

.co-card-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.co-card-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--co-stu-border-light);
}

/* Badges */
.co-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.co-badge.primary {
  background: var(--co-stu-primary-light);
  color: var(--co-stu-primary);
}

.co-badge.success {
  background: var(--co-stu-success-light);
  color: var(--co-stu-success);
}

.co-badge.warning {
  background: var(--co-stu-warning-light);
  color: var(--co-stu-warning);
}

.co-badge.danger {
  background: var(--co-stu-danger-light);
  color: var(--co-stu-danger);
}

.co-badge.neutral {
  background: var(--co-stu-bg-alt);
  color: var(--co-stu-text-muted);
}

/* Progress bar */
.co-progress-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 100%;
}

.co-progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--co-stu-text-muted);
}

.co-progress-track {
  height: 7px;
  background: var(--co-stu-bg-alt);
  border-radius: 999px;
  overflow: hidden;
  position: relative;
}

.co-progress-bar {
  height: 100%;
  background: var(--co-stu-primary-gradient);
  border-radius: 999px;
  transition: width 0.35s ease;
}

/* Table wrapper */
.co-table-wrap {
  background: var(--co-stu-surface);
  border: 1px solid var(--co-stu-border);
  border-radius: var(--co-stu-radius);
  box-shadow: var(--co-stu-shadow-sm);
  overflow-x: auto;
  width: 100%;
}

.co-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.86rem;
}

.co-table th {
  background: var(--co-stu-bg);
  color: var(--co-stu-text-muted);
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.85rem 1.15rem;
  border-bottom: 1px solid var(--co-stu-border);
  white-space: nowrap;
}

.co-table td {
  padding: 0.95rem 1.15rem;
  border-bottom: 1px solid var(--co-stu-border-light);
  color: var(--co-stu-text);
  vertical-align: middle;
}

.co-table tr:last-child td {
  border-bottom: none;
}

.co-table tr:hover td {
  background: var(--co-stu-surface-hover);
}

/* Feedback States: Empty, Loading, Error */
.co-empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 3.5rem 1.5rem;
  background: var(--co-stu-surface);
  border: 1px dashed var(--co-stu-border);
  border-radius: var(--co-stu-radius-lg);
  gap: 0.85rem;
  width: 100%;
}

.co-empty-state i.empty-icon {
  font-size: 2.5rem;
  color: var(--co-stu-text-light);
  background: var(--co-stu-bg);
  width: 68px;
  height: 68px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.co-empty-state h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--co-stu-text);
  margin: 0;
}

.co-empty-state p {
  font-size: 0.86rem;
  color: var(--co-stu-text-muted);
  max-width: 44ch;
  margin: 0;
}

.co-skeleton {
  background: linear-gradient(90deg, var(--co-stu-bg) 25%, var(--co-stu-surface-hover) 50%, var(--co-stu-bg) 75%);
  background-size: 200% 100%;
  animation: co-shimmer 1.5s infinite;
  border-radius: 6px;
  height: 18px;
}

@keyframes co-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ==========================================================================
   STRICT MOBILE BREAKPOINTS (Zero Overflow & Drawer UX)
   ========================================================================== */

@media (max-width: 1200px) {
  .co-kpi-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 1024px) {
  .co-student-sidebar {
    transform: translateX(-100%);
  }
  .co-student-sidebar.active {
    transform: translateX(0);
  }
  .co-sidebar-close {
    display: block;
  }
  .co-student-main {
    margin-left: 0 !important;
    max-width: 100vw !important;
    width: 100% !important;
  }
  .co-mobile-toggle {
    display: block;
  }
  .co-dashboard-layout {
    grid-template-columns: 1fr;
  }
  .co-student-container {
    padding: 1.25rem;
  }
}

@media (max-width: 768px) {
  .co-student-topbar {
    padding: 0 0.85rem;
  }
  .topbar-search {
    display: none !important;
  }
  .co-dashboard-content {
    padding: 1rem;
    gap: 1rem;
  }
  .co-student-container {
    padding: 1rem;
    gap: 1rem;
  }
  .co-page-header {
    flex-direction: column;
    align-items: flex-start;
  }
  .co-page-header-actions {
    width: 100%;
  }
  .co-page-header-actions .btn-stu {
    flex: 1;
    text-align: center;
    justify-content: center;
  }
  .co-filter-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .co-filter-group {
    width: 100%;
    flex-direction: column;
    align-items: stretch;
  }
  .co-search-box {
    max-width: 100%;
    width: 100%;
  }
  .co-filter-select {
    width: 100%;
  }
  .co-stu-hero {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.25rem;
  }
  .co-hero-actions {
    width: 100%;
    flex-direction: column;
  }
  .co-hero-actions .btn-stu {
    width: 100%;
  }
  .co-kpi-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
  }
  .co-card-grid {
    grid-template-columns: 1fr;
  }
  .co-quick-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
  }
}

@media (max-width: 540px) {
  .co-kpi-grid {
    grid-template-columns: 1fr;
  }
  .co-quick-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .header-badge {
    display: none;
  }
  .profile-meta {
    display: none;
  }
  .co-hero-greeting {
    font-size: 1.35rem;
  }
}