/* 
 * RC Theme — Universal Design System for Reinisch Classroom
 * Single source of truth for colors, typography, spacing, and components
 * Used across all student-facing pages and Teacher Center
 */

/* ============================================================
   DESIGN TOKENS — CSS Custom Properties
   ============================================================ */

:root {
  /* Surfaces */
  --rc-base: #0b1220;
  --rc-panel: #0f172a;
  --rc-panel-2: #111827;
  --rc-glass: rgba(0, 0, 0, 0.34);
  --rc-glass-border: rgba(255, 255, 255, 0.08);
  --rc-glass-hover: rgba(255, 255, 255, 0.07);
  --rc-glass-active: rgba(255, 255, 255, 0.10);
  
  /* Text */
  --rc-ink: rgba(240, 255, 250, 0.92);
  --rc-ink-dim: rgba(240, 255, 250, 0.78);
  --rc-muted: #94a3b8;
  
  /* Borders */
  --rc-border: rgba(255, 255, 255, 0.08);
  --rc-border-strong: rgba(255, 255, 255, 0.14);
  
  /* Brand / Accent */
  --rc-brand: #22c55e;
  --rc-brand-2: #06b6d4;
  
  /* Semantic */
  --rc-success: #22c55e;
  --rc-warning: #f59e0b;
  --rc-danger: #ef4444;
  --rc-info: #3b82f6;
  
  /* Typography */
  --rc-font: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --rc-font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  
  /* Spacing */
  --rc-radius-sm: 8px;
  --rc-radius: 12px;
  --rc-radius-lg: 18px;
  --rc-radius-pill: 999px;
  
  /* Shadows */
  --rc-shadow: 0 18px 60px rgba(0, 0, 0, 0.35);
  --rc-shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* ============================================================
   BASE RESET & BODY
   ============================================================ */

*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: var(--rc-font);
  font-size: 16px;
  color: var(--rc-ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  letter-spacing: 0.1px;
  
  background:
    radial-gradient(1200px 800px at 20% -10%, rgba(34, 197, 94, 0.22), transparent 50%),
    radial-gradient(1000px 600px at 50% 30%, rgba(34, 197, 94, 0.10), transparent 60%),
    radial-gradient(1200px 800px at 120% 20%, rgba(6, 182, 212, 0.12), transparent 50%),
    linear-gradient(180deg, #0b1220, #0c1322 60%, #0b0f14);
}

/* ============================================================
   SHARED COMPONENT CLASSES
   ============================================================ */

/* Cards */
.rc-card {
  background: var(--rc-glass);
  border: 1px solid var(--rc-glass-border);
  border-radius: var(--rc-radius-lg);
  padding: 24px;
  box-shadow: var(--rc-shadow);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.rc-card:hover {
  background: var(--rc-glass-hover);
}

/* Buttons */
.rc-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--rc-radius);
  border: 1px solid var(--rc-border);
  background: var(--rc-glass);
  color: var(--rc-ink);
  font-family: var(--rc-font);
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.rc-btn:hover {
  background: var(--rc-glass-hover);
  transform: translateY(-1px);
}

.rc-btn:active {
  transform: translateY(0);
}

.rc-btn.primary {
  background: rgba(148, 163, 184, 0.15);
  border: 1px solid rgba(148, 163, 184, 0.3);
  color: var(--rc-ink, #e8f1ec);
  font-weight: 600;
}

.rc-btn.primary:hover {
  background: rgba(148, 163, 184, 0.22);
  border-color: rgba(148, 163, 184, 0.4);
}

.rc-btn.danger {
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.25);
  color: rgba(239, 68, 68, 0.9);
  font-weight: 600;
}

.rc-btn.danger:hover {
  background: rgba(239, 68, 68, 0.18);
  border-color: rgba(239, 68, 68, 0.35);
}

/* Form Inputs */
.rc-input,
.rc-select,
.rc-textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--rc-radius);
  border: 1px solid var(--rc-border);
  background: rgba(0, 0, 0, 0.22);
  color: var(--rc-ink);
  font-family: var(--rc-font);
  font-size: 16px;
  outline: none;
  transition: border-color 0.2s ease;
}

.rc-input:focus,
.rc-select:focus,
.rc-textarea:focus {
  border-color: var(--rc-brand);
}

.rc-textarea {
  resize: vertical;
  min-height: 100px;
}

/* Tables */
.rc-table {
  width: 100%;
  border-collapse: collapse;
}

.rc-table th,
.rc-table td {
  padding: 11px 14px;
  text-align: left;
}

.rc-table thead th {
  position: sticky;
  top: 0;
  background: rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rc-border-strong);
  font-size: 12px;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--rc-ink-dim);
  font-weight: 600;
}

.rc-table tbody tr {
  border-bottom: 1px solid var(--rc-border);
  cursor: pointer;
  transition: background 0.2s ease;
}

.rc-table tbody tr:hover {
  background: var(--rc-glass-hover);
}

/* Badges */
.rc-badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--rc-radius-pill);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.rc-badge.success {
  background: rgba(34, 197, 94, 0.15);
  color: var(--rc-success);
}

.rc-badge.warning {
  background: rgba(245, 158, 11, 0.15);
  color: var(--rc-warning);
}

.rc-badge.danger {
  background: rgba(239, 68, 68, 0.15);
  color: var(--rc-danger);
}

.rc-badge.info {
  background: rgba(59, 130, 246, 0.15);
  color: var(--rc-info);
}

/* Pills / Tags */
.rc-pill {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: var(--rc-radius-pill);
  background: var(--rc-glass);
  border: 1px solid var(--rc-border);
  font-size: 14px;
  color: var(--rc-ink);
}

/* Dividers */
.rc-divider {
  height: 1px;
  background: var(--rc-border);
  margin: 14px 0;
  border: none;
}

/* Typography */
.rc-heading {
  margin: 0 0 10px;
  font-size: 38px;
  line-height: 1.05;
  letter-spacing: -0.02em;
  font-weight: 850;
  color: var(--rc-ink);
}

.rc-heading-2 {
  margin: 6px 0 10px;
  font-size: 22px;
  letter-spacing: -0.01em;
  font-weight: 700;
  color: var(--rc-ink);
}

.rc-muted {
  color: var(--rc-muted);
}

/* Grid Utility */
.rc-grid {
  display: grid;
  gap: 1.25rem;
}

.rc-grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.rc-grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.rc-grid-auto {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

/* Container */
.rc-container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding: 0 1rem;
}

/* ============================================================
   RESPONSIVE BREAKPOINTS
   ============================================================ */

@media (max-width: 1100px) {
  .rc-grid-2,
  .rc-grid-3 {
    grid-template-columns: 1fr;
  }
  
  .rc-heading {
    font-size: 32px;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }
  
  .rc-card {
    padding: 18px;
  }
  
  .rc-btn {
    padding: 9px 16px;
    font-size: 15px;
  }
  
  .rc-heading {
    font-size: 28px;
  }
  
  .rc-heading-2 {
    font-size: 20px;
  }
}

/* ============================================================
   STATUS DOT UTILITIES
   ============================================================ */

.rc-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

.rc-status-dot--ok { background: rgba(34, 197, 94, 0.85); }
.rc-status-dot--warn { background: rgba(245, 158, 11, 0.85); }
.rc-status-dot--error { background: rgba(239, 68, 68, 0.85); }
.rc-status-dot--loading {
  background: rgba(148, 163, 184, 0.5);
  animation: rc-pulse 1.5s ease-in-out infinite;
}

@keyframes rc-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}