/* ============================================
   FocusAgent Base Styles
   Deep Space Dark Theme + Global Utilities
   ============================================ */

/* === External Resources === */
@import url('../vendor/fontawesome/css/all.min.css');

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-ui);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--space-void);
  background-image: var(--gradient-mesh);
  background-attachment: fixed;
  overflow-x: hidden;
  min-height: 100vh;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--cyan-400);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--cyan-300);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: var(--text-primary);
  background: var(--space-surface);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  padding: var(--space-xs) var(--space-sm);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--cyan-500);
  box-shadow: 0 0 0 3px rgba(6, 182, 212, 0.15);
}

/* === Layout === */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* === Glass Card Component === */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--glass-shadow);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base),
    border-color var(--transition-glow);
}

.glass-card:hover {
  transform: translateY(-3px);
  background: var(--glass-bg-hover);
  border-color: var(--glass-border-hover);
  box-shadow:
    var(--glass-shadow),
    0 12px 40px rgba(0, 0, 0, 0.3);
}

/* Glass card glow variants */
.glass-card-cyan {
  background: var(--card-cyan-bg);
  border-color: var(--card-cyan-border);
}

.glass-card-cyan:hover {
  border-color: var(--glass-border-cyan);
  box-shadow: var(--shadow-cyan-glow);
}

.glass-card-amber {
  background: var(--card-amber-bg);
  border-color: var(--card-amber-border);
}

.glass-card-amber:hover {
  border-color: var(--glass-border-amber);
  box-shadow: var(--shadow-amber-glow);
}

.glass-card-emerald {
  background: var(--card-emerald-bg);
  border-color: var(--card-emerald-border);
}

.glass-card-emerald:hover {
  border-color: var(--glass-border-emerald);
  box-shadow: var(--shadow-emerald-glow);
}

.glass-card-rose {
  background: var(--card-rose-bg);
  border-color: var(--card-rose-border);
}

.glass-card-rose:hover {
  border-color: var(--glass-border-rose);
  box-shadow: var(--shadow-rose-glow);
}

/* === Gradient Text === */
.gradient-text {
  background: var(--gradient-cosmic);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-text-energy {
  background: var(--gradient-energy);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-text-success {
  background: var(--gradient-success);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* === Button Styles === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-weight: var(--weight-semibold);
  font-size: var(--text-base);
  font-family: var(--font-ui);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--gradient-cosmic);
  color: white;
  box-shadow: var(--shadow-md), var(--shadow-cyan-glow);
}

.btn-primary:hover {
  background: var(--gradient-cosmic-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), var(--glow-cyan);
}

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

.btn-secondary {
  background: rgba(6, 182, 212, 0.1);
  color: var(--cyan-400);
  border: 1px solid rgba(6, 182, 212, 0.3);
}

.btn-secondary:hover {
  background: rgba(6, 182, 212, 0.2);
  border-color: rgba(6, 182, 212, 0.5);
  box-shadow: var(--shadow-cyan-glow);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: rgba(148, 163, 184, 0.08);
  color: var(--text-primary);
}

/* Cosmic gradient button */
.btn-cosmic {
  background: var(--gradient-cosmic);
  color: white;
  font-weight: var(--weight-bold);
  padding: 14px 36px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md), var(--shadow-cyan-glow);
  letter-spacing: 0.02em;
}

.btn-cosmic:hover {
  background: var(--gradient-cosmic-hover);
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-lg), var(--glow-intense-cyan);
}

.btn-cosmic:active {
  transform: translateY(0) scale(0.98);
}

/* Glow button */
.btn-glow {
  background: rgba(6, 182, 212, 0.12);
  color: var(--cyan-400);
  border: 1px solid rgba(6, 182, 212, 0.3);
  padding: 12px 28px;
  border-radius: var(--radius-sm);
}

.btn-glow:hover {
  background: rgba(6, 182, 212, 0.2);
  border-color: rgba(6, 182, 212, 0.6);
  box-shadow: var(--glow-cyan);
  transform: translateY(-2px);
}

/* Outline button (dark theme) */
.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--neutral-300);
  padding: 12px 28px;
  border-radius: var(--radius-sm);
}

.btn-outline:hover {
  color: var(--text-primary);
  border-color: var(--neutral-400);
  background: rgba(148, 163, 184, 0.06);
}

/* Shimmer effect for buttons */
.btn-shimmer::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.12),
    transparent
  );
  animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

/* === Progress Bar Component === */
.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(148, 163, 184, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-bar-fill {
  height: 100%;
  border-radius: var(--radius-full);
  background: var(--progress-cyan);
  transition: width 0.6s var(--ease-elastic);
  position: relative;
}

.progress-bar-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.2) 50%,
    transparent 100%
  );
  animation: progress-shimmer 2s ease-in-out infinite;
}

@keyframes progress-shimmer {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

.progress-bar-amber .progress-bar-fill {
  background: var(--progress-amber);
}

.progress-bar-emerald .progress-bar-fill {
  background: var(--progress-emerald);
}

.progress-bar-rose .progress-bar-fill {
  background: var(--progress-rose);
}

/* Progress bar with glow */
.progress-bar-glow .progress-bar-fill {
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.4);
}

/* === Badge Component === */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.badge-gold {
  background: var(--badge-gold-bg);
  border: 1px solid var(--badge-gold-border);
  color: var(--badge-gold-text);
}

.badge-silver {
  background: var(--badge-silver-bg);
  border: 1px solid var(--badge-silver-border);
  color: var(--badge-silver-text);
}

.badge-bronze {
  background: var(--badge-bronze-bg);
  border: 1px solid var(--badge-bronze-border);
  color: var(--badge-bronze-text);
}

.badge-special {
  background: var(--badge-special-bg);
  border: 1px solid var(--badge-special-border);
  color: var(--badge-special-text);
}

.badge-cyan {
  background: rgba(6, 182, 212, 0.12);
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: var(--cyan-400);
}

.badge-amber {
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.3);
  color: var(--amber-400);
}

.badge-emerald {
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: var(--emerald-400);
}

/* === Stat Card Component === */
.stat-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  transition: all var(--transition-base);
}

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

.stat-card-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--icon-lg);
  margin-bottom: var(--space-2xs);
}

.stat-card-icon.cyan {
  background: rgba(6, 182, 212, 0.12);
  color: var(--cyan-400);
}

.stat-card-icon.amber {
  background: rgba(245, 158, 11, 0.12);
  color: var(--amber-400);
}

.stat-card-icon.emerald {
  background: rgba(16, 185, 129, 0.12);
  color: var(--emerald-400);
}

.stat-card-icon.rose {
  background: rgba(244, 63, 94, 0.12);
  color: var(--teacher-400);
}

.stat-card-value {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
  line-height: 1.1;
}

.stat-card-label {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* === Sidebar Nav Component === */
.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
}

.sidebar-nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px var(--space-md);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  transition: all var(--transition-fast);
  cursor: pointer;
  position: relative;
}

.sidebar-nav-item i {
  width: 20px;
  text-align: center;
  font-size: var(--icon-md);
}

.sidebar-nav-item:hover {
  color: var(--text-primary);
  background: rgba(148, 163, 184, 0.06);
}

.sidebar-nav-item.active {
  color: var(--cyan-400);
  background: rgba(6, 182, 212, 0.1);
}

.sidebar-nav-item.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 60%;
  background: var(--cyan-500);
  border-radius: 0 var(--radius-xs) var(--radius-xs) 0;
}

/* === Training Node Component === */
.training-node {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: all var(--transition-base);
  cursor: pointer;
}

.training-node-completed {
  background: var(--node-completed-bg);
  border-color: var(--node-completed-border);
}

.training-node-completed:hover {
  box-shadow: var(--shadow-emerald-glow);
  border-color: rgba(16, 185, 129, 0.7);
}

.training-node-current {
  background: var(--node-current-bg);
  border-color: var(--node-current-border);
  animation: glow-pulse 2.5s ease-in-out infinite;
}

.training-node-current:hover {
  box-shadow: var(--shadow-cyan-glow);
  border-color: rgba(6, 182, 212, 0.7);
}

.training-node-locked {
  background: var(--node-locked-bg);
  border-color: var(--node-locked-border);
  opacity: 0.6;
  cursor: not-allowed;
}

.training-node-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--icon-md);
  flex-shrink: 0;
}

.training-node-completed .training-node-icon {
  background: rgba(16, 185, 129, 0.2);
  color: var(--emerald-400);
}

.training-node-current .training-node-icon {
  background: rgba(6, 182, 212, 0.2);
  color: var(--cyan-400);
}

.training-node-locked .training-node-icon {
  background: rgba(100, 116, 139, 0.15);
  color: var(--neutral-500);
}

/* === Challenge Card Component === */
.challenge-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.challenge-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-cosmic);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.challenge-card:hover {
  border-color: var(--glass-border-cyan);
  transform: translateY(-4px);
  box-shadow: var(--shadow-cyan-glow);
}

.challenge-card:hover::before {
  opacity: 1;
}

.challenge-card-difficulty {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.challenge-card-difficulty.easy {
  background: rgba(16, 185, 129, 0.12);
  color: var(--emerald-400);
}

.challenge-card-difficulty.medium {
  background: rgba(245, 158, 11, 0.12);
  color: var(--amber-400);
}

.challenge-card-difficulty.hard {
  background: rgba(244, 63, 94, 0.12);
  color: var(--teacher-400);
}

/* === Achievement Badge Component === */
.achievement-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  text-align: center;
  transition: all var(--transition-base);
  cursor: default;
}

.achievement-badge-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--icon-xl);
  position: relative;
}

.achievement-badge-icon::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  transition: border-color var(--transition-glow);
}

.achievement-badge:hover .achievement-badge-icon::after {
  border-color: currentColor;
  opacity: 0.4;
}

.achievement-badge.gold .achievement-badge-icon {
  background: var(--badge-gold-bg);
  color: var(--badge-gold-text);
  box-shadow: 0 0 20px rgba(251, 191, 36, 0.2);
}

.achievement-badge.silver .achievement-badge-icon {
  background: var(--badge-silver-bg);
  color: var(--badge-silver-text);
  box-shadow: 0 0 20px rgba(148, 163, 184, 0.15);
}

.achievement-badge.bronze .achievement-badge-icon {
  background: var(--badge-bronze-bg);
  color: var(--badge-bronze-text);
  box-shadow: 0 0 20px rgba(180, 83, 9, 0.15);
}

.achievement-badge.special .achievement-badge-icon {
  background: var(--badge-special-bg);
  color: var(--badge-special-text);
  box-shadow: 0 0 20px rgba(6, 182, 212, 0.2);
}

.achievement-badge.locked {
  opacity: 0.35;
  filter: grayscale(0.8);
}

.achievement-badge-title {
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
  color: var(--text-secondary);
  max-width: 80px;
  line-height: 1.3;
}

/* === Toast Notification === */
.toast-container {
  position: fixed;
  top: var(--space-lg);
  right: var(--space-lg);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 14px var(--space-md);
  background: var(--space-elevated);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  color: var(--text-primary);
  font-size: var(--text-sm);
  pointer-events: auto;
  animation: slide-up 0.4s var(--ease-elastic) forwards;
  max-width: 380px;
}

.toast-icon {
  font-size: var(--icon-lg);
  flex-shrink: 0;
}

.toast-success .toast-icon { color: var(--emerald-400); }
.toast-warning .toast-icon { color: var(--amber-400); }
.toast-error .toast-icon   { color: var(--status-error-500); }
.toast-info .toast-icon    { color: var(--cyan-400); }

.toast-success { border-left: 3px solid var(--emerald-500); }
.toast-warning { border-left: 3px solid var(--amber-500); }
.toast-error   { border-left: 3px solid var(--status-error-500); }
.toast-info    { border-left: 3px solid var(--cyan-500); }

.toast-exit {
  animation: fade-out 0.3s var(--ease-elastic) forwards;
}

/* === Modal Component === */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: var(--space-overlay);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: var(--z-modal-backdrop);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  animation: fade-in 0.2s var(--ease-smooth);
}

.modal {
  background: var(--space-mid);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  max-width: 520px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  animation: fade-in-scale 0.35s var(--ease-elastic);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--glass-border);
}

.modal-header h3 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  color: var(--text-primary);
}

.modal-close {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all var(--transition-fast);
  background: transparent;
  border: none;
  cursor: pointer;
}

.modal-close:hover {
  color: var(--text-primary);
  background: rgba(148, 163, 184, 0.1);
}

.modal-body {
  padding: var(--space-lg);
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--glass-border);
}

/* === Utility Classes === */
.text-glow-cyan {
  text-shadow: 0 0 10px rgba(6, 182, 212, 0.5), 0 0 30px rgba(6, 182, 212, 0.2);
}

.text-glow-amber {
  text-shadow: 0 0 10px rgba(245, 158, 11, 0.5), 0 0 30px rgba(245, 158, 11, 0.2);
}

.text-glow-emerald {
  text-shadow: 0 0 10px rgba(16, 185, 129, 0.5), 0 0 30px rgba(16, 185, 129, 0.2);
}

.border-glow-cyan {
  box-shadow: var(--shadow-cyan-glow);
}

.border-glow-amber {
  box-shadow: var(--shadow-amber-glow);
}

.border-glow-emerald {
  box-shadow: var(--shadow-emerald-glow);
}

.bg-glow-cyan {
  box-shadow: var(--glow-cyan);
}

.bg-glow-amber {
  box-shadow: var(--glow-amber);
}

.bg-glow-emerald {
  box-shadow: var(--glow-emerald);
}

/* === Number Animation === */
.number-animate {
  display: inline-block;
  font-variant-numeric: tabular-nums;
  transition: transform 0.3s var(--ease-elastic);
}

.number-animate.bump {
  transform: scale(1.15);
}

/* === Section Reveal Animation === */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s var(--ease-elastic),
              transform 0.8s var(--ease-elastic);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered children reveal */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.5s var(--ease-elastic);
}

.reveal-stagger.visible > *:nth-child(1)  { transition-delay: 0.05s; }
.reveal-stagger.visible > *:nth-child(2)  { transition-delay: 0.1s; }
.reveal-stagger.visible > *:nth-child(3)  { transition-delay: 0.15s; }
.reveal-stagger.visible > *:nth-child(4)  { transition-delay: 0.2s; }
.reveal-stagger.visible > *:nth-child(5)  { transition-delay: 0.25s; }
.reveal-stagger.visible > *:nth-child(6)  { transition-delay: 0.3s; }
.reveal-stagger.visible > *:nth-child(7)  { transition-delay: 0.35s; }
.reveal-stagger.visible > *:nth-child(8)  { transition-delay: 0.4s; }
.reveal-stagger.visible > *:nth-child(9)  { transition-delay: 0.45s; }
.reveal-stagger.visible > *:nth-child(10) { transition-delay: 0.5s; }

.reveal-stagger.visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* === Keyframe Animations === */
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes floatSlow {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  33% { transform: translateY(-8px) rotate(1deg); }
  66% { transform: translateY(-4px) rotate(-1deg); }
}

@keyframes glow-pulse {
  0%, 100% {
    box-shadow: 0 0 15px rgba(6, 182, 212, 0.2);
  }
  50% {
    box-shadow: 0 0 30px rgba(6, 182, 212, 0.35),
                0 0 50px rgba(6, 182, 212, 0.1);
  }
}

@keyframes pulse-glow {
  0%, 100% {
    box-shadow: 0 0 20px rgba(6, 182, 212, 0.25);
  }
  50% {
    box-shadow: 0 0 40px rgba(6, 182, 212, 0.4),
                0 0 60px rgba(245, 158, 11, 0.15);
  }
}

@keyframes slide-up {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fade-out {
  from { opacity: 1; transform: translateY(0); }
  to { opacity: 0; transform: translateY(-10px); }
}

@keyframes fade-in-scale {
  from {
    opacity: 0;
    transform: scale(0.92);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes rotate-slow {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes bounce-subtle {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

@keyframes gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.animated-gradient {
  background-size: 200% 200%;
  animation: gradient-shift 8s ease infinite;
}

/* === Selection Style === */
::selection {
  background: rgba(6, 182, 212, 0.3);
  color: var(--text-primary);
}

/* === Scrollbar Styling (dark theme) === */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--space-deep);
}

::-webkit-scrollbar-thumb {
  background: var(--space-elevated);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--neutral-400);
}

/* === Responsive Breakpoints === */
@media (max-width: 1536px) {
  :root { --container-max: 1280px; }
}

@media (max-width: 1280px) {
  :root { --container-max: 1024px; }
}

@media (max-width: 1024px) {
  .container {
    padding: 0 var(--space-md);
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-sm);
  }

  .stat-card {
    padding: var(--space-sm);
  }

  .stat-card-value {
    font-size: var(--text-2xl);
  }

  .modal {
    margin: var(--space-sm);
    max-height: 90vh;
  }

  .modal-header,
  .modal-body,
  .modal-footer {
    padding: var(--space-sm) var(--space-md);
  }
}

@media (max-width: 640px) {
  .btn {
    padding: 10px 20px;
    font-size: var(--text-sm);
  }

  .btn-cosmic {
    padding: 12px 28px;
  }

  .challenge-card {
    padding: var(--space-md);
  }

  .toast-container {
    left: var(--space-sm);
    right: var(--space-sm);
    top: var(--space-sm);
  }

  .toast {
    max-width: 100%;
  }
}

/* ============================================
   Component Visual States
   Deep Space Dark Theme Enhancements
   ============================================ */

/* === 1. Button Loading State === */
.btn-loading {
  position: relative;
  color: transparent;
  pointer-events: none;
}

.btn-loading::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 16px;
  height: 16px;
  margin-top: -8px;
  margin-left: -8px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: var(--radius-full);
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* === 2. Button Disabled State === */
.btn:disabled,
.btn[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
  filter: grayscale(0.3);
}

/* === 3. Card Active / Selected State === */
.glass-card.active,
.glass-card.is-active {
  border-color: var(--cyan-400);
  box-shadow: 0 0 0 1px var(--cyan-400), var(--shadow-cyan-glow);
}

/* === 4. Card Loading State === */
.glass-card.is-loading {
  min-height: 120px;
  position: relative;
  overflow: hidden;
}

.glass-card.is-loading > * {
  opacity: 0.3;
  pointer-events: none;
}

/* === 5. Card Empty State === */
.glass-card.is-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 120px;
  color: var(--neutral-400);
}

.glass-card.is-empty::after {
  content: '\6682\65e0\6570\636e';
  font-size: var(--text-sm);
  color: var(--neutral-400);
}

/* === 6. Input Error State === */
.input-error,
input.is-error {
  border-color: var(--rose-500);
  box-shadow: 0 0 0 3px rgba(244, 63, 94, 0.15);
}

/* === 7. Input Success State === */
.input-success,
input.is-success {
  border-color: var(--emerald-500);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

/* === 8. Ripple Click Effect === */
.ripple {
  position: relative;
  overflow: hidden;
}

.ripple::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100%;
  padding-top: 100%;
  border-radius: var(--radius-full);
  background: var(--ripple-color);
  transform: scale(0);
  opacity: 0;
  pointer-events: none;
}

.ripple.ripple-active::after {
  animation: ripple-expand var(--ripple-duration) var(--ease-smooth) forwards;
}

@keyframes ripple-expand {
  0% {
    transform: scale(0);
    opacity: 1;
  }
  100% {
    transform: scale(var(--ripple-scale));
    opacity: 0;
  }
}

/* === 9. Press Bounce Effect === */
.press-bounce {
  transition: transform 0.15s var(--ease-elastic);
}

.press-bounce:active {
  transform: scale(0.96);
}

/* === 10. Skeleton Loading Effect === */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--neutral-800) 25%,
    var(--neutral-700) 50%,
    var(--neutral-800) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

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

/* === 11. Hover Glow Effect === */
.hover-glow {
  transition:
    box-shadow 0.3s var(--ease-smooth),
    transform 0.3s var(--ease-smooth);
}

.hover-glow:hover {
  box-shadow:
    0 0 20px rgba(6, 182, 212, 0.2),
    0 8px 32px rgba(0, 0, 0, 0.3);
  transform: translateY(-2px);
}

/* === 12. Card Top Border Reveal Effect === */
.card-reveal {
  position: relative;
  overflow: hidden;
}

.card-reveal::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-cosmic);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease-elastic);
}

.card-reveal:hover::before {
  transform: scaleX(1);
}