/**
 * ============================================================
 * KỸ NĂNG VIỆT – DESIGN SYSTEM
 * ============================================================
 * Mục đích: Tokens + utility classes duy nhất cho toàn bộ dự án
 * Load sau Bootstrap, trước style-kynangviet.css
 * ============================================================
 */

/* ===== 1. TOKENS ===== */
:root {
  /* Primary – Blue */
  --primary:        #005EB8;
  --primary-light:  #E6F0FA;
  --primary-dark:   #003D7A;
  --navy:           #012A4A;

  /* Secondary – Gold */
  --secondary:        #C4A35A;
  --secondary-light:  #F5EFE0;
  --secondary-hover:  #D4B76A;

  /* Semantic */
  --success: #10B981;
  --danger:  #EF4444;
  --warning: #F59E0B;
  --info:    #0EA5E9;

  /* Surface / Text / Border */
  --bg:           #F8FAFC;
  --surface:      #FFFFFF;
  --surface-alt:  #F1F5F9;
  --text-primary:   #0F172A;
  --text-secondary: #475569;
  --text-muted:     #94A3B8;
  --white-color:    #FFFFFF;

  --border:        #E2E8F0;
  --border-active: #005EB8;

  /* Shadows */
  --shadow-card:       0 4px 24px rgba(0, 94, 184, 0.06);
  --shadow-card-hover: 0 12px 40px rgba(0, 94, 184, 0.10);
  --shadow-float:      0 20px 60px rgba(0, 0, 0, 0.12);
  --shadow-header:     0 2px 20px rgba(0, 0, 0, 0.06);
  --shadow-gold:       0 8px 24px rgba(196, 163, 90, 0.35);
  --shadow-gold-hover: 0 12px 32px rgba(196, 163, 90, 0.45);

  /* Radius */
  --radius-sm:  8px;
  --radius-md:  12px;
  --radius-lg:  16px;
  --radius-xl:  20px;
  --radius-2xl: 24px;
  --radius-pill: 50px;

  /* Typography */
  --font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== 2. BASE ===== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background-color: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-base);
}
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; display: block; }

/* ===== 3. TYPOGRAPHY ===== */
.knv-font-serif { font-family: var(--font-serif); }

.knv-h1 { font-size: clamp(36px, 5vw, 56px); font-weight: 700; line-height: 1.15; }
.knv-h2 { font-size: clamp(28px, 3.5vw, 40px); font-weight: 700; line-height: 1.2; }
.knv-h3 { font-size: clamp(22px, 2.5vw, 28px); font-weight: 700; line-height: 1.3; }
.knv-h4 { font-size: 20px; font-weight: 600; line-height: 1.4; }

.knv-text-lg  { font-size: 18px; }
.knv-text-base{ font-size: 16px; }
.knv-text-sm  { font-size: 14px; }
.knv-text-xs  { font-size: 13px; }

.knv-label {
  font-size: 13px; font-weight: 600; text-transform: uppercase;
  letter-spacing: 2px; color: var(--secondary);
}

/* ===== 4. COLORS – BACKGROUND ===== */
.knv-bg-primary       { background-color: var(--primary) !important; }
.knv-bg-primary-light { background-color: var(--primary-light) !important; }
.knv-bg-primary-dark  { background-color: var(--primary-dark) !important; }
.knv-bg-navy          { background-color: var(--navy) !important; }
.knv-bg-secondary     { background-color: var(--secondary) !important; }
.knv-bg-secondary-light{ background-color: var(--secondary-light) !important; }
.knv-bg-success       { background-color: var(--success) !important; }
.knv-bg-danger        { background-color: var(--danger) !important; }
.knv-bg-warning       { background-color: var(--warning) !important; }
.knv-bg-info          { background-color: var(--info) !important; }
.knv-bg-bg            { background-color: var(--bg) !important; }
.knv-bg-surface       { background-color: var(--surface) !important; }
.knv-bg-surface-alt   { background-color: var(--surface-alt) !important; }

/* ===== 5. COLORS – TEXT ===== */
.knv-text-primary-color   { color: var(--text-primary) !important; }
.knv-text-secondary-color { color: var(--text-secondary) !important; }
.knv-text-muted-color     { color: var(--text-muted) !important; }
.knv-text-white-color     { color: var(--white-color) !important; }
.knv-text-blue            { color: var(--primary) !important; }
.knv-text-gold            { color: var(--secondary) !important; }
.knv-text-success         { color: var(--success) !important; }
.knv-text-danger          { color: var(--danger) !important; }

/* ===== 6. BUTTONS ===== */
.knv-btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; font-weight: 600; border: none; cursor: pointer;
  transition: all var(--transition-base); white-space: nowrap;
}
.knv-btn:hover { transform: scale(1.02); }

.knv-btn-sm  { padding: 8px 18px;  border-radius: var(--radius-md); font-size: 14px; }
.knv-btn-md  { padding: 10px 22px; border-radius: var(--radius-md); font-size: 14px; }
.knv-btn-lg  { padding: 14px 36px; border-radius: var(--radius-md); font-size: 16px; }

.knv-btn-primary {
  background-color: var(--primary); color: #fff;
}
.knv-btn-primary:hover {
  background-color: var(--primary-dark); color: #fff;
  box-shadow: 0 4px 16px rgba(0, 94, 184, 0.3);
}

.knv-btn-outline-primary {
  background: transparent; border: 1.5px solid var(--primary); color: var(--primary);
}
.knv-btn-outline-primary:hover {
  background: var(--primary-light); color: var(--primary);
}

.knv-btn-gold {
  background: linear-gradient(90deg, var(--secondary), var(--secondary-hover));
  color: #1E293B; box-shadow: var(--shadow-gold);
}
.knv-btn-gold:hover { filter: brightness(1.05); box-shadow: var(--shadow-gold-hover); }

.knv-btn-outline-light {
  background: transparent; border: 1.5px solid rgba(255,255,255,0.3); color: #fff;
}
.knv-btn-outline-light:hover {
  background: rgba(255,255,255,0.08); border-color: rgba(255,255,255,0.5); color: #fff;
}

.knv-btn-danger {
  background-color: var(--danger); color: #fff;
}
.knv-btn-danger:hover { background-color: #DC2626; color: #fff; }

.knv-btn-success {
  background-color: var(--success); color: #fff;
}
.knv-btn-success:hover { background-color: #059669; color: #fff; }

/* ===== 7. CARDS ===== */
.knv-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-xl); padding: 32px 28px;
  box-shadow: var(--shadow-card); transition: all var(--transition-slow); height: 100%;
}
.knv-card:hover {
  transform: translateY(-8px); box-shadow: var(--shadow-card-hover); border-color: var(--border-active);
}
.knv-card-sm { padding: 24px; border-radius: var(--radius-lg); }
.knv-card-static { transition: none; transform: none !important; }

/* ===== 8. BADGES ===== */
.knv-badge {
  display: inline-block; padding: 4px 12px; border-radius: 6px;
  font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px;
}
.knv-badge-blue  { background: var(--primary); color: #fff; }
.knv-badge-gold  { background: var(--secondary); color: #1E293B; }
.knv-badge-light { background: var(--primary-light); color: var(--primary); }

/* ===== 9. PILLS ===== */
.knv-pill {
  display: inline-block; padding: 8px 18px; border-radius: var(--radius-pill);
  font-size: 14px; font-weight: 600; cursor: pointer;
  transition: all var(--transition-base); border: 1.5px solid var(--border);
  background: var(--bg); color: var(--text-secondary); user-select: none;
}
.knv-pill:hover {
  border-color: var(--primary); color: var(--primary); background: var(--primary-light);
}
.knv-pill.active-blue {
  background: var(--primary); color: #fff; border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(0, 94, 184, 0.25);
}
.knv-pill.active-gold {
  background: var(--secondary); color: #1E293B; border-color: var(--secondary);
  box-shadow: 0 4px 12px rgba(196, 163, 90, 0.25);
}

/* ===== 10. FORMS ===== */
.knv-form-control {
  width: 100%; padding: 12px 16px; font-size: 15px; font-family: var(--font-sans);
  color: var(--text-primary); background: var(--surface);
  border: 1.5px solid var(--border); border-radius: var(--radius-md);
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
}
.knv-form-control:focus {
  outline: none; border-color: var(--border-active);
  box-shadow: 0 0 0 3px rgba(0, 94, 184, 0.1);
}
.knv-form-control::placeholder { color: var(--text-muted); }

.knv-form-label {
  display: block; font-size: 14px; font-weight: 600;
  color: var(--text-primary); margin-bottom: 6px;
}
.knv-form-group { margin-bottom: 20px; }

/* ===== 11. SECTION UTILITIES ===== */
.knv-section      { padding: 80px 0; }
.knv-section-alt  { background: var(--surface); }

.knv-section-header { margin-bottom: 60px; }
.knv-section-header--center { text-align: center; }

.knv-section-label {
  font-size: 13px; font-weight: 600; text-transform: uppercase;
  letter-spacing: 2px; color: var(--secondary); margin-bottom: 12px;
}
.knv-section-title {
  font-size: clamp(28px, 3.5vw, 40px); font-weight: 700;
  color: var(--text-primary); line-height: 1.2; margin-bottom: 16px;
}
.knv-section-subtitle {
  font-size: 16px; color: var(--text-secondary); max-width: 560px;
}

/* ===== 12. WAVE DIVIDER ===== */
.knv-wave-divider {
  position: absolute; bottom: 0; left: 0; right: 0; line-height: 0;
}
.knv-wave-divider svg { display: block; width: 100%; height: 80px; }

/* ===== 13. GLASSMORPHISM ===== */
.knv-glass {
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

/* ===== 14. ANIMATIONS ===== */
@keyframes knvFloat {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-12px); }
}
@keyframes knvFadeInUp {
  from { opacity: 0; transform: translateY(40px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes knvSpin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.knv-animate-float { animation: knvFloat 4s ease-in-out infinite; }
.knv-animate-spin  { animation: knvSpin 1s linear infinite; }

.knv-reveal {
  opacity: 0; transform: translateY(40px);
}
.knv-reveal.is-visible {
  animation: knvFadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* ===== 15. UTILITIES ===== */
.knv-shadow-card        { box-shadow: var(--shadow-card); }
.knv-shadow-card-hover:hover { box-shadow: var(--shadow-card-hover); }
.knv-shadow-float       { box-shadow: var(--shadow-float); }

.knv-radius-sm  { border-radius: var(--radius-sm); }
.knv-radius-md  { border-radius: var(--radius-md); }
.knv-radius-lg  { border-radius: var(--radius-lg); }
.knv-radius-xl  { border-radius: var(--radius-xl); }
.knv-radius-2xl { border-radius: var(--radius-2xl); }
.knv-radius-pill{ border-radius: var(--radius-pill); }

.knv-border        { border: 1px solid var(--border); }
.knv-border-active { border-color: var(--border-active); }

/* ===== 16. RESPONSIVE ===== */
@media (max-width: 991.98px) {
  .knv-section { padding: 60px 0; }
  .knv-exam-card { padding: 28px; }
}

@media (max-width: 768px) {
  .knv-section-title { font-size: 26px; }
  .knv-step-item { margin-bottom: 32px; }
}

@media (max-width: 576px) {
  .knv-btn-lg { padding: 12px 24px; font-size: 15px; }
  .knv-exam-card { padding: 24px; }
  .knv-question-card { padding: 20px; }
}

@media (max-width: 350px) {
  .knv-logo-text { font-size: 16px; }
}

/* ============================================================
 * PHASE 4.5 — Tabs Lớp 9-12 (shared: de-thi-thu + trac-nghiem-lop)
 * Class chính: .dt-lop-tabs > .dt-lop-tab (specificity > Bootstrap .nav-pills .nav-link)
 * ============================================================ */
.dt-lop-tabs { list-style: none; padding-left: 0; margin: 0; }
.dt-lop-tabs .dt-lop-tab {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .6rem 1.25rem;
  border-radius: 999px;
  background: var(--surface, #f3f6fb);
  color: var(--navy, #1d3a5f);
  border: 1px solid #c5cfdb;
  font-weight: 600;
  transition: all .2s ease;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 1px 0 rgba(29, 58, 95, .04);
}
.dt-lop-tabs .dt-lop-tab:hover {
  border-color: var(--primary, #2e6cb6);
  color: var(--primary, #2e6cb6);
  background: #fff;
}
.dt-lop-tabs .dt-lop-tab.active {
  background: var(--primary, #2e6cb6);
  border-color: var(--primary, #2e6cb6);
  color: #fff;
  box-shadow: 0 4px 12px rgba(46, 108, 182, .25);
}
.dt-lop-tabs .dt-lop-tab iconify-icon { font-size: 1rem; }
.dt-exam-grid-transition { transition: opacity 250ms ease; }

@media (max-width: 576px) {
  .dt-lop-tabs .dt-lop-tab { padding: .5rem 1rem; font-size: .9rem; }
}

/* ============================================================
 * Action Menu — dropdown gộp các nút thao tác trên row bảng admin.
 * Dùng chung cho admin-cau-hoi, admin-de-thi, admin-hoc-sinh, …
 * ============================================================ */
.knv-actmenu {
  position: relative;
  display: inline-block;
}
.knv-actmenu__toggle {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: transparent;
  border: 1px solid transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary, #64748b);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  padding: 0;
  font-size: 14px;
}
.knv-actmenu__toggle:hover,
.knv-actmenu.is-open .knv-actmenu__toggle {
  background: var(--surface-alt, #f1f5f9);
  color: var(--text-primary, #0f172a);
  border-color: var(--border, #e2e8f0);
}
.knv-actmenu__toggle iconify-icon {
  font-size: 16px;
  pointer-events: none;
}
.knv-actmenu__menu {
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  min-width: 180px;
  background: var(--surface, #fff);
  border: 1px solid var(--border, #e2e8f0);
  border-radius: 10px;
  box-shadow: 0 6px 18px rgba(15, 23, 42, 0.08);
  padding: 4px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-4px);
  transition: opacity 0.15s ease, transform 0.15s ease;
  z-index: 40;
}
.knv-actmenu.is-open .knv-actmenu__menu {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
.knv-actmenu__item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 8px 12px;
  border-radius: 6px;
  background: transparent;
  border: 0;
  color: var(--text-primary, #0f172a);
  font-size: 13px;
  text-align: left;
  cursor: pointer;
  white-space: nowrap;
  text-decoration: none;
  font-family: inherit;
  line-height: 1.4;
}
.knv-actmenu__item:hover,
.knv-actmenu__item:focus-visible {
  background: var(--surface-alt, #f1f5f9);
  color: var(--text-primary, #0f172a);
  outline: none;
}
.knv-actmenu__item iconify-icon {
  font-size: 14px;
  flex-shrink: 0;
  color: var(--text-secondary, #64748b);
}
.knv-actmenu__item--danger {
  color: var(--danger, #ef4444);
}
.knv-actmenu__item--danger iconify-icon {
  color: var(--danger, #ef4444);
}
.knv-actmenu__item--danger:hover,
.knv-actmenu__item--danger:focus-visible {
  background: rgba(239, 68, 68, 0.08);
  color: var(--danger, #ef4444);
}
.knv-actmenu__divider {
  height: 1px;
  background: var(--border, #e2e8f0);
  margin: 4px 0;
}

@media (max-width: 575.98px) {
  .knv-actmenu__menu {
    right: auto;
    left: 0;
  }
}