/* EduDaily — Main CSS (mobile-first) */

:root {
  --edu-primary:        #3B82F6;
  --edu-primary-dark:   #2563EB;
  --edu-success:        #10B981;
  --edu-error:          #EF4444;
  --edu-warning:        #F59E0B;
  --edu-bg:             #F8FAFC;
  --edu-surface:        #FFFFFF;
  --edu-text:           #1E293B;
  --edu-text-secondary: #64748B;
  --edu-border:         #E2E8F0;

  --edu-math: #8B5CF6;
  --edu-ukr:  #EAB308;
  --edu-pol:  #DC2626;
  --edu-eng:  #2563EB;

  --edu-font:      'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --edu-font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --edu-radius:    12px;
  --edu-radius-sm: 8px;
  --edu-radius-xs: 4px;

  --edu-shadow:    0 1px 3px rgba(0,0,0,0.1);
  --edu-shadow-lg: 0 4px 12px rgba(0,0,0,0.15);

  --edu-nav-height: 64px;
}

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

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body.edudaily-page {
  background: var(--edu-bg);
  color: var(--edu-text);
  font-family: var(--edu-font);
  line-height: 1.5;
  min-height: 100vh;
  padding-bottom: var(--edu-nav-height);
}

/* Container */
.edu-container {
  padding: 2px;
  max-width: 100%;
  width: 100%;
}

/* Typography */
.edu-h1 { font-size: 1.5rem; font-weight: 700; line-height: 1.2; }
.edu-h2 { font-size: 1.25rem; font-weight: 600; line-height: 1.3; }
.edu-h3 { font-size: 1.1rem; font-weight: 600; }
.edu-text-sm { font-size: 0.875rem; }
.edu-text-xs { font-size: 0.75rem; }
.edu-text-muted { color: var(--edu-text-secondary); }

/* Card */
.edu-card {
  background: var(--edu-surface);
  border-radius: var(--edu-radius);
  box-shadow: var(--edu-shadow);
  padding: 16px;
  margin-bottom: 12px;
}
.edu-card--flat {
  box-shadow: none;
  border: 1px solid var(--edu-border);
}

/* Buttons */
.edu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: none;
  border-radius: var(--edu-radius-sm);
  cursor: pointer;
  font-family: var(--edu-font);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1;
  padding: 12px 20px;
  text-decoration: none;
  transition: background 0.15s, transform 0.1s, opacity 0.15s;
  min-height: 44px;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}
.edu-btn:active { transform: scale(0.97); }
.edu-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.edu-btn--primary { background: var(--edu-primary); color: #fff; }
.edu-btn--primary:hover:not(:disabled) { background: var(--edu-primary-dark); }

.edu-btn--success { background: var(--edu-success); color: #fff; }
.edu-btn--danger  { background: var(--edu-error); color: #fff; }
.edu-btn--ghost   { background: transparent; color: var(--edu-primary); border: 1px solid var(--edu-primary); }
.edu-btn--ghost:hover:not(:disabled) { background: rgba(59,130,246,0.08); }
.edu-btn--secondary { background: var(--edu-border); color: var(--edu-text); }
.edu-btn--secondary:hover:not(:disabled) { background: #d1d5db; }

.edu-btn--sm { font-size: 0.8125rem; padding: 8px 14px; min-height: 36px; }
.edu-btn--full { width: 100%; }
.edu-btn--icon { padding: 10px; min-width: 44px; border-radius: 50%; }

/* Inputs */
.edu-input-group { margin-bottom: 14px; }
.edu-label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 6px; color: var(--edu-text); }
.edu-input {
  width: 100%;
  background: var(--edu-surface);
  border: 1.5px solid var(--edu-border);
  border-radius: var(--edu-radius-sm);
  color: var(--edu-text);
  font-family: var(--edu-font);
  font-size: 1rem;
  padding: 11px 14px;
  transition: border-color 0.15s;
  -webkit-appearance: none;
}
.edu-input:focus { outline: none; border-color: var(--edu-primary); }
.edu-input.is-error { border-color: var(--edu-error); }
.edu-input.is-success { border-color: var(--edu-success); }
.edu-field-error { color: var(--edu-error); font-size: 0.8125rem; margin-top: 4px; display: none; }
.edu-field-error.is-visible { display: block; }

/* Progress bar */
.edu-progress { background: var(--edu-border); border-radius: 99px; height: 8px; overflow: hidden; }
.edu-progress__bar {
  background: var(--edu-primary);
  border-radius: 99px;
  height: 100%;
  transition: width 0.4s ease;
}
.edu-progress__bar--success { background: var(--edu-success); }
.edu-progress__bar--warning { background: var(--edu-warning); }

/* Badge */
.edu-badge {
  display: inline-flex;
  align-items: center;
  border-radius: 99px;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 8px;
  white-space: nowrap;
}
.edu-badge--blue    { background: #DBEAFE; color: #1D4ED8; }
.edu-badge--green   { background: #D1FAE5; color: #065F46; }
.edu-badge--yellow  { background: #FEF3C7; color: #92400E; }
.edu-badge--red     { background: #FEE2E2; color: #991B1B; }
.edu-badge--purple  { background: #EDE9FE; color: #5B21B6; }
.edu-badge--gray    { background: #F1F5F9; color: #475569; }

/* Alert */
.edu-alert {
  border-radius: var(--edu-radius-sm);
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  font-size: 0.9rem;
  margin-bottom: 12px;
}
.edu-alert--error   { background: #FEE2E2; color: #991B1B; }
.edu-alert--success { background: #D1FAE5; color: #065F46; }
.edu-alert--info    { background: #DBEAFE; color: #1E40AF; }

/* Header */
.edu-header {
  background: var(--edu-surface);
  border-bottom: 1px solid var(--edu-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.edu-header__title { font-size: 1.125rem; font-weight: 700; }
.edu-header__back  {
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  color: var(--edu-primary);
  font-size: 1.25rem;
  line-height: 1;
  min-width: 32px;
}

/* Bottom navigation */
.edu-bottom-nav {
  background: var(--edu-surface);
  border-top: 1px solid var(--edu-border);
  bottom: 0;
  display: flex;
  height: var(--edu-nav-height);
  left: 0;
  position: fixed;
  right: 0;
  z-index: 200;
}
.edu-bottom-nav__item {
  align-items: center;
  background: none;
  border: none;
  color: var(--edu-text-secondary);
  cursor: pointer;
  display: flex;
  flex: 1;
  flex-direction: column;
  font-family: var(--edu-font);
  font-size: 0.6875rem;
  font-weight: 500;
  gap: 3px;
  justify-content: center;
  padding: 8px 4px;
  text-decoration: none;
  transition: color 0.15s;
  -webkit-tap-highlight-color: transparent;
}
.edu-bottom-nav__item.is-active { color: var(--edu-primary); }
.edu-bottom-nav__icon { font-size: 1.375rem; line-height: 1; }

/* Subject colors */
.edu-subject--math { --subject-color: var(--edu-math); }
.edu-subject--ukr  { --subject-color: var(--edu-ukr); }
.edu-subject--pol  { --subject-color: var(--edu-pol); }
.edu-subject--eng  { --subject-color: var(--edu-eng); }

/* Loading skeleton */
.edu-skeleton {
  background: linear-gradient(90deg, #E2E8F0 25%, #F1F5F9 50%, #E2E8F0 75%);
  background-size: 200% 100%;
  animation: edu-skeleton-pulse 1.5s infinite;
  border-radius: var(--edu-radius-sm);
}
@keyframes edu-skeleton-pulse {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* Spinner */
.edu-spinner {
  width: 24px; height: 24px;
  border: 3px solid var(--edu-border);
  border-top-color: var(--edu-primary);
  border-radius: 50%;
  animation: edu-spin 0.7s linear infinite;
  display: inline-block;
}
@keyframes edu-spin { to { transform: rotate(360deg); } }

/* Loading overlay */
.edu-loading {
  align-items: center;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 40px 16px;
  text-align: center;
  color: var(--edu-text-secondary);
}

/* Empty state */
.edu-empty {
  align-items: center;
  color: var(--edu-text-secondary);
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 40px 16px;
  text-align: center;
}
.edu-empty__icon { font-size: 3rem; }
.edu-empty__text { font-size: 0.9375rem; }

/* Shake animation for wrong answers */
@keyframes edu-shake {
  0%, 100% { transform: translateX(0); }
  20%  { transform: translateX(-6px); }
  40%  { transform: translateX(6px); }
  60%  { transform: translateX(-4px); }
  80%  { transform: translateX(4px); }
}
.edu-shake { animation: edu-shake 0.4s ease; }

/* Flash animation */
@keyframes edu-flash-green {
  0%   { background: var(--edu-success); }
  100% { background: transparent; }
}
@keyframes edu-flash-red {
  0%   { background: var(--edu-error); }
  100% { background: transparent; }
}

/* Divider */
.edu-divider {
  border: none;
  border-top: 1px solid var(--edu-border);
  margin: 16px 0;
}

/* Section title */
.edu-section-title {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--edu-text-secondary);
  margin-bottom: 10px;
}

/* Streak badge */
.edu-streak {
  align-items: center;
  display: inline-flex;
  gap: 4px;
  font-weight: 700;
  font-size: 1.1rem;
}
.edu-streak__icon { font-size: 1.25rem; }

/* Tablet */
@media (min-width: 768px) {
  .edu-container {
    padding: 24px;
    max-width: 768px;
    margin: 0 auto;
  }
  .edu-card { padding: 20px; }
}

/* Desktop */
@media (min-width: 1200px) {
  body.edudaily-page { padding-bottom: 0; }
  .edu-container { max-width: 1200px; }
  .edu-layout {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 24px;
    align-items: start;
  }
  .edu-bottom-nav { display: none; }
  .edu-sidebar {
    background: var(--edu-surface);
    border-radius: var(--edu-radius);
    box-shadow: var(--edu-shadow);
    padding: 16px 0;
    position: sticky;
    top: 80px;
  }
  .edu-sidebar__item {
    align-items: center;
    color: var(--edu-text-secondary);
    display: flex;
    gap: 10px;
    padding: 11px 20px;
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    background: none;
    border: none;
    width: 100%;
    font-family: var(--edu-font);
    transition: background 0.15s, color 0.15s;
    border-radius: 0;
  }
  .edu-sidebar__item:hover { background: var(--edu-bg); color: var(--edu-text); }
  .edu-sidebar__item.is-active { background: #EFF6FF; color: var(--edu-primary); font-weight: 600; }
  .edu-sidebar__icon { font-size: 1.25rem; }
}