/* ============================================================
   School Command Center — Design System
   Dark theme with glassmorphism, premium feel
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Base palette */
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: rgba(17, 24, 39, 0.7);
  --bg-card-hover: rgba(17, 24, 39, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.04);
  --bg-glass-hover: rgba(255, 255, 255, 0.08);
  
  /* Borders */
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-medium: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(99, 102, 241, 0.3);
  
  /* Text */
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-accent: #a5b4fc;
  
  /* Event type colors */
  --color-missing: #ef4444;
  --color-missing-bg: rgba(239, 68, 68, 0.12);
  --color-missing-border: rgba(239, 68, 68, 0.3);
  
  --color-test: #f59e0b;
  --color-test-bg: rgba(245, 158, 11, 0.12);
  --color-test-border: rgba(245, 158, 11, 0.3);
  
  --color-assignment: #3b82f6;
  --color-assignment-bg: rgba(59, 130, 246, 0.12);
  --color-assignment-border: rgba(59, 130, 246, 0.3);
  
  --color-activity: #10b981;
  --color-activity-bg: rgba(16, 185, 129, 0.12);
  --color-activity-border: rgba(16, 185, 129, 0.3);
  
  --color-notification: #8b5cf6;
  --color-notification-bg: rgba(139, 92, 246, 0.12);
  --color-notification-border: rgba(139, 92, 246, 0.3);
  
  --color-ai: #6366f1;
  --color-ai-bg: rgba(99, 102, 241, 0.12);
  --color-ai-border: rgba(99, 102, 241, 0.3);
  --color-ai-glow: rgba(99, 102, 241, 0.15);
  
  /* Student colors */
  --color-student-1: #818cf8;
  --color-student-2: #34d399;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  
  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms ease;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
}

/* Ambient background gradient */
body::before {
  content: '';
  position: fixed;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at 30% 20%, rgba(99, 102, 241, 0.06) 0%, transparent 50%),
              radial-gradient(ellipse at 70% 80%, rgba(139, 92, 246, 0.04) 0%, transparent 50%);
  z-index: -1;
  pointer-events: none;
}

/* --- Layout --- */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-lg);
}

@media (max-width: 640px) {
  .container {
    padding: var(--space-md);
  }
}

/* --- Header --- */
.header {
  text-align: center;
  padding: var(--space-2xl) 0 var(--space-xl);
  position: relative;
}

.header__icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-sm);
  display: block;
}

.header__title {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #f1f5f9 0%, #a5b4fc 50%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--space-xs);
}

.header__subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* --- Glass Card --- */
.card {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-normal);
}

.card:hover {
  border-color: var(--border-medium);
}

.card__title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.card__title-icon {
  font-size: 1rem;
}

/* --- Briefing Summary Cards --- */
.briefing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-md);
}

.briefing-stat {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-lg) var(--space-md);
  text-align: center;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.briefing-stat:hover {
  transform: translateY(-2px);
  border-color: var(--border-medium);
}

.briefing-stat--missing {
  border-color: var(--color-missing-border);
  background: var(--color-missing-bg);
}

.briefing-stat--missing:hover {
  box-shadow: 0 4px 20px rgba(239, 68, 68, 0.15);
}

.briefing-stat--tests {
  border-color: var(--color-test-border);
  background: var(--color-test-bg);
}

.briefing-stat--tests:hover {
  box-shadow: 0 4px 20px rgba(245, 158, 11, 0.15);
}

.briefing-stat--assignments {
  border-color: var(--color-assignment-border);
  background: var(--color-assignment-bg);
}

.briefing-stat--assignments:hover {
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.15);
}

.briefing-stat--ai {
  border-color: var(--color-ai-border);
  background: var(--color-ai-bg);
}

.briefing-stat--ai:hover {
  box-shadow: 0 4px 20px var(--color-ai-glow);
}

.briefing-stat__number {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  margin-bottom: var(--space-sm);
}

.briefing-stat--missing .briefing-stat__number { color: var(--color-missing); }
.briefing-stat--tests .briefing-stat__number { color: var(--color-test); }
.briefing-stat--assignments .briefing-stat__number { color: var(--color-assignment); }
.briefing-stat--ai .briefing-stat__number { color: var(--color-ai); }

.briefing-stat__label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  line-height: 1.3;
}

/* --- Student Filter Tabs --- */
.filter-tabs {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.filter-tab {
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid var(--border-medium);
  background: var(--bg-glass);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 6px;
}

.filter-tab:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
}

.filter-tab--active {
  background: rgba(99, 102, 241, 0.15);
  border-color: var(--color-ai-border);
  color: var(--text-accent);
}

.filter-tab__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}

/* --- Calendar Grid --- */
.calendar {
  overflow-x: auto;
}

.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
  min-width: 500px;
}

.calendar-header {
  padding: var(--space-sm);
  text-align: center;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.calendar-day {
  min-height: 80px;
  padding: var(--space-sm);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  background: var(--bg-glass);
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
}

.calendar-day:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-medium);
}

.calendar-day--today {
  border-color: var(--color-ai-border);
  background: rgba(99, 102, 241, 0.06);
}

.calendar-day--empty {
  opacity: 0.3;
  cursor: default;
}

.calendar-day--empty:hover {
  background: var(--bg-glass);
  border-color: var(--border-subtle);
}

.calendar-day__number {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.calendar-day--today .calendar-day__number {
  color: var(--color-ai);
  font-weight: 800;
}

.calendar-day__events {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.calendar-event-pill {
  font-size: 0.6rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: var(--radius-full);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  line-height: 1.4;
}

.calendar-event-pill--missing {
  background: var(--color-missing-bg);
  color: var(--color-missing);
  border: 1px solid var(--color-missing-border);
}

.calendar-event-pill--test,
.calendar-event-pill--quiz,
.calendar-event-pill--exam {
  background: var(--color-test-bg);
  color: var(--color-test);
  border: 1px solid var(--color-test-border);
}

.calendar-event-pill--homework,
.calendar-event-pill--assignment,
.calendar-event-pill--project {
  background: var(--color-assignment-bg);
  color: var(--color-assignment);
  border: 1px solid var(--color-assignment-border);
}

.calendar-event-pill--event,
.calendar-event-pill--activity {
  background: var(--color-activity-bg);
  color: var(--color-activity);
  border: 1px solid var(--color-activity-border);
}

/* Day detail popup */
.day-detail {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: -20px;
  right: -20px;
  min-width: 220px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  box-shadow: var(--shadow-card);
  z-index: 100;
  cursor: default;
}

.calendar-day.expanded .day-detail {
  display: block;
  animation: fadeSlideIn 0.2s ease;
}

.day-detail__item {
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.78rem;
}

.day-detail__item:last-child {
  border-bottom: none;
}

/* --- Student Section --- */
.student-section {
  animation: fadeSlideIn 0.4s ease;
}

.student-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--border-subtle);
}

.student-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 800;
  color: white;
  flex-shrink: 0;
}

.student-avatar--1 {
  background: linear-gradient(135deg, #6366f1, #818cf8);
}

.student-avatar--2 {
  background: linear-gradient(135deg, #059669, #34d399);
}

.student-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.student-grade {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* --- Event Items --- */
.event-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.event-group {
  margin-bottom: var(--space-lg);
}

.event-group__title {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.event-group__title--missing { color: var(--color-missing); }
.event-group__title--tests { color: var(--color-test); }
.event-group__title--assignments { color: var(--color-assignment); }
.event-group__title--notifications { color: var(--color-notification); }

.event-item {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  transition: all var(--transition-fast);
  position: relative;
}

.event-item:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-medium);
  transform: translateX(2px);
}

.event-item--missing {
  border-left: 3px solid var(--color-missing);
}

.event-item--test,
.event-item--quiz,
.event-item--exam {
  border-left: 3px solid var(--color-test);
}

.event-item--homework,
.event-item--assignment,
.event-item--project {
  border-left: 3px solid var(--color-assignment);
}

.event-item--notification {
  border-left: 3px solid var(--color-notification);
}

.event-item__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.event-item__title {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
  flex: 1;
}

.event-item__meta {
  font-size: 0.72rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  margin-top: 2px;
}

.event-item__details {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-top: var(--space-sm);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--border-subtle);
  line-height: 1.5;
}

.event-item__source {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 0.65rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  margin-top: var(--space-sm);
}

.event-item__source--ai {
  background: var(--color-ai-bg);
  border-color: var(--color-ai-border);
  color: var(--color-ai);
}

.event-item__source--calendar {
  background: var(--color-activity-bg);
  border-color: var(--color-activity-border);
  color: var(--color-activity);
}

.event-item__source--schoology {
  background: var(--color-notification-bg);
  border-color: var(--color-notification-border);
  color: var(--color-notification);
}

/* --- Countdown Badge --- */
.countdown {
  font-size: 0.68rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  white-space: nowrap;
  flex-shrink: 0;
}

.countdown--urgent {
  background: rgba(239, 68, 68, 0.15);
  color: var(--color-missing);
  animation: pulse 2s ease-in-out infinite;
}

.countdown--soon {
  background: rgba(245, 158, 11, 0.15);
  color: var(--color-test);
}

.countdown--normal {
  background: rgba(59, 130, 246, 0.1);
  color: var(--color-assignment);
}

.countdown--far {
  background: var(--bg-glass);
  color: var(--text-muted);
}

/* --- Notification Content --- */
.notification-content {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.notification-author {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.notification-course {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: var(--color-notification-bg);
  color: var(--color-notification);
  margin-bottom: var(--space-sm);
}

.download-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--color-assignment);
  text-decoration: none;
  padding: var(--space-xs) var(--space-sm);
  border: 1px solid var(--color-assignment-border);
  border-radius: var(--radius-sm);
  margin-top: var(--space-sm);
  transition: all var(--transition-fast);
}

.download-link:hover {
  background: var(--color-assignment-bg);
}

/* --- Empty State --- */
.empty-state {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
  padding: var(--space-md);
  text-align: center;
}

.empty-state--good {
  color: var(--color-activity);
  font-style: normal;
  font-weight: 600;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: var(--space-2xl) 0 var(--space-lg);
  font-size: 0.72rem;
  color: var(--text-muted);
}

.footer a {
  color: var(--text-accent);
  text-decoration: none;
}

/* --- Animations --- */
@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

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

/* Loading skeleton */
.skeleton {
  background: linear-gradient(90deg, var(--bg-glass) 25%, var(--bg-glass-hover) 50%, var(--bg-glass) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s ease infinite;
  border-radius: var(--radius-sm);
  height: 20px;
  margin-bottom: var(--space-sm);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .header__title {
    font-size: 1.35rem;
  }
  
  .briefing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .calendar-day {
    min-height: 60px;
    padding: 4px;
  }
  
  .calendar-day__number {
    font-size: 0.65rem;
  }
  
  .calendar-event-pill {
    font-size: 0.5rem;
    padding: 1px 4px;
  }
  
  .student-section .card {
    padding: var(--space-md);
  }
}

@media (max-width: 480px) {
  .briefing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .briefing-stat__number {
    font-size: 1.5rem;
  }
  
  .filter-tabs {
    gap: var(--space-xs);
  }
  
  .filter-tab {
    font-size: 0.72rem;
    padding: 6px 10px;
  }
}