/* K-PASS mobile enhancements — điện thoại & máy tính bảng */

@media (max-width: 1024px) {
  :root {
    --mobile-header-offset: calc(4.25rem + env(safe-area-inset-top, 0px));
  }

  .app-header:not(.app-header-exam) {
    padding-top: calc(0.9rem + env(safe-area-inset-top, 0px));
    padding-left: calc(1rem + env(safe-area-inset-left, 0px));
    padding-right: calc(1rem + env(safe-area-inset-right, 0px));
  }

  .app-header:not(.app-header-exam) .app-header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
  }

  .app-footer {
    padding-bottom: calc(0.75rem + env(safe-area-inset-bottom, 0px));
    padding-left: calc(1rem + env(safe-area-inset-left, 0px));
    padding-right: calc(1rem + env(safe-area-inset-right, 0px));
  }

  .app-main:not(.app-main-exam) {
    padding-left: max(1rem, env(safe-area-inset-left, 0px));
    padding-right: max(1rem, env(safe-area-inset-right, 0px));
  }

  body.mobile-nav-open {
    overflow: hidden;
  }

  /* Hamburger button */
  .mobile-nav-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    min-width: 44px;
    min-height: 44px;
    padding: 0;
    border: var(--border);
    border-radius: var(--radius-sm);
    background: var(--white);
    cursor: pointer;
    flex-shrink: 0;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .mobile-nav-toggle-bar {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--gray-800);
    border-radius: 1px;
    transition: transform 0.2s ease, opacity 0.2s ease;
  }

  body.mobile-nav-open .mobile-nav-toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  body.mobile-nav-open .mobile-nav-toggle-bar:nth-child(2) {
    opacity: 0;
  }

  body.mobile-nav-open .mobile-nav-toggle-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* Ẩn menu ngang, mở dạng drawer */
  .app-nav-wrap .app-nav {
    display: none;
  }

  .app-nav-wrap.is-open .mobile-nav-backdrop {
    display: block;
  }

  .app-nav-wrap.is-open .app-nav {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--mobile-header-offset);
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 120;
    margin: 0;
    padding: 0.35rem 0 calc(1rem + env(safe-area-inset-bottom, 0px));
    background: var(--white);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    box-shadow: var(--shadow-lg);
    gap: 0;
  }

  .mobile-nav-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 110;
    background: rgba(15, 23, 42, 0.45);
    border: none;
    cursor: pointer;
    touch-action: manipulation;
  }

  .app-nav-wrap .nav-link {
    width: 100%;
    min-height: 48px;
    padding: 0.85rem 1.25rem;
    font-size: 0.95rem;
    border-bottom: 1px solid var(--gray-100);
    border-left: 3px solid transparent;
    margin-bottom: 0;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .app-nav-wrap .nav-link.active {
    border-bottom-color: var(--gray-100);
    border-left-color: var(--blue);
    background: var(--blue-soft);
  }

  /* Vùng chạm lớn hơn */
  .btn {
    min-height: 44px;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .btn-group .btn {
    min-height: 40px;
  }

  .exam-option {
    min-height: 48px;
    padding: 1rem 1.1rem;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
  }

  .q-nav-btn {
    width: 44px;
    height: 44px;
    touch-action: manipulation;
  }

  .answer-pick-chip,
  .answer-type-btn {
    min-height: 44px;
    touch-action: manipulation;
  }

  .set-view-btn,
  .nav-link {
    touch-action: manipulation;
  }

  /* exam-nav-fab: xử lý trong exam-mobile-cloud.css */

  .ui-toast-stack {
    bottom: calc(1rem + env(safe-area-inset-bottom, 0px));
    left: max(1rem, env(safe-area-inset-left, 0px));
    right: max(1rem, env(safe-area-inset-right, 0px));
  }

  .exam-modal-overlay {
    padding: max(1rem, env(safe-area-inset-top, 0px)) max(1rem, env(safe-area-inset-right, 0px))
      max(1rem, env(safe-area-inset-bottom, 0px)) max(1rem, env(safe-area-inset-left, 0px));
  }
}

/* PC lớn — không dùng drawer */
@media (min-width: 1025px) {
  .mobile-nav-toggle,
  .mobile-nav-backdrop {
    display: none !important;
  }

  body.mobile-nav-open {
    overflow: auto;
  }
}