/* ==================== APP LAYOUT ==================== */
.app-container {
  display: flex;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

/* ==================== SIDEBAR ==================== */
.sidebar {
  display: flex;
  flex-direction: column;
  z-index: 100;
  width: var(--sidebar-width);
  transition: width var(--duration-normal) var(--ease-decelerate);

  background: var(--acrylic-bg);
  backdrop-filter: blur(var(--acrylic-blur)) saturate(120%);
  -webkit-backdrop-filter: blur(var(--acrylic-blur)) saturate(120%);
  border-right: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);

  &.collapsed {
    width: var(--sidebar-collapsed-width);

    & .logo-title-btn {
      max-width: 0;
      margin-left: 0;
      opacity: 0;
      pointer-events: none;
      cursor: default;
      overflow: hidden;
    }

    & .nav-links {
      scrollbar-width: none;
      -ms-overflow-style: none;
      overflow: hidden !important;

      &::-webkit-scrollbar {
        width: 0;
        display: none;
      }
    }

    & .collapsed-divider {
      display: block;
    }

    & .nav-item > span:not(.icon) {
      max-width: 0;
      opacity: 0;
    }

    & .nav-item.is-separator {
      font-size: 0;
      padding-top: 6px;
      padding-bottom: 2px;
      margin-top: var(--spacing-xs);
      height: 28px;
      line-height: normal;
      text-align: center;
      display: flex;
      justify-content: center;
      align-items: center;

      &::before,
      & > span {
        display: none;
      }

      &::after {
        content: "—";
        font-size: var(--font-size-body);
        color: var(--text-tertiary);
        opacity: 0.5;
      }
    }
  }
}

/* Sidebar Logo */
.logo {
  display: flex;
  align-items: center;
  height: var(--header-height);
  min-height: var(--header-height);
  padding: var(--spacing-sm) var(--spacing-lg);
  overflow: hidden;
  white-space: nowrap;

  border-bottom: 1px solid var(--border-subtle);

  & span {
    font-size: var(--font-size-subtitle);
    font-weight: 600;
    letter-spacing: -0.02em;

    margin-left: var(--spacing-sm);
    max-width: 150px;
    opacity: 1;
    transition:
      opacity 0.2s var(--ease-standard),
      max-width 0.3s var(--ease-standard),
      margin-left 0.3s var(--ease-standard);

    color: var(--text-primary);
  }
}

/* Logo Text Animation */
.logo-title-container {
  user-select: none;

  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
}

.logo-chevron {
  font-size: 0.8em;

  opacity: 0.7;
}

/* Sidebar Toggle Button & Icons */
.sidebar-toggle-btn-inner,
.nav-item .icon,
.nav-item i {
  font-size: 1.222rem;
  line-height: 1;

  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex-shrink: 0;

  color: var(--text-secondary);
}

/* Sidebar Toggle Button Specifics */
.sidebar-toggle-btn-inner {
  display: flex;
  padding: 0;
  transition: background var(--duration-normal);
  cursor: pointer;

  background: transparent;
  border: none;
  border-radius: var(--radius-md);

  &:hover {
    background: var(--card-bg-hover);
    color: var(--text-primary);
  }
}

/* Navigation Links Container */
.nav-links {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  padding: var(--spacing-xs);
  gap: 2px;
  overflow-y: auto;
  overflow-y: overlay; /* Overlay scrollbar for cleaner look */
  overflow-x: hidden;
}

.nav-divider {
  height: 1px;
  margin: var(--spacing-xs) var(--spacing-sm);

  background: var(--border-subtle);
}

.nav-label {
  font-size: var(--font-size-caption);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: var(--spacing-md) var(--spacing-sm) var(--spacing-xs)
    var(--spacing-sm);
  color: var(--text-tertiary);
  opacity: 0.8;
}

/* Nav Item Layout */
.nav-item {
  font-family: inherit;
  font-size: var(--font-size-body);
  text-align: left;

  display: flex;
  align-items: center;
  justify-content: flex-start;
  width: 100%;
  position: relative;
  padding: 10px var(--spacing-sm);
  gap: var(--spacing-sm);
  cursor: pointer;
  overflow: hidden;
  white-space: nowrap;
  flex-shrink: 0;
  transition: all var(--duration-normal) var(--ease-standard);

  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  color: var(--text-secondary);

  & > span:not(.icon) {
    max-width: 150px;
    opacity: 1;
    transition:
      opacity 0.2s var(--ease-standard),
      max-width 0.3s var(--ease-standard);
  }

  &::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%) scaleY(0);
    width: 3px;
    height: 16px;
    transition: transform var(--duration-normal) var(--ease-decelerate);

    background: var(--accent-default);
    border-radius: var(--radius-pill);
  }

  &.active::before {
    transform: translateY(-50%) scaleY(1);
  }

  &:hover {
    background: var(--card-bg-hover);
    color: var(--text-primary);
  }

  &.active {
    background: var(--accent-tertiary);
    color: var(--accent-default);
  }

  & .icon {
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    flex-shrink: 0;
    transition: all var(--duration-normal) var(--ease-standard);
  }

  /* Special/Pseudobank Icon Treatment */
  &.is-special,
  &.is-pseudobank {
    & > span:not(.icon) {
      font-weight: 500;
      text-decoration: underline;
      text-decoration-thickness: 0.5px;
      text-decoration-style: dashed;
      text-underline-offset: 4px;
    }

    & .icon {
      background: var(--accent-secondary);
      border-radius: var(--radius-md);
      color: var(--accent-default);
      outline: solid var(--accent-default) 1px;
    }

    & .pseudobank-badge {
      display: inline-block;
      font-size: 0.9em;
      opacity: 0.7;
      margin-left: 4px;
      vertical-align: middle;
      text-decoration: none !important;
      line-height: normal;
    }
  }

  /* Separator Modifier */
  &.is-separator {
    font-size: 0.722rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;

    margin-top: var(--spacing-xs);
    padding-top: 6px;
    padding-bottom: 2px;
    height: 28px; /* Fixed height to prevent layout shifts */
    line-height: normal;
    display: flex;
    align-items: center;
    pointer-events: none;
    cursor: default;

    background: transparent !important;
    border-color: transparent !important;
    padding-left: var(--spacing-sm);

    /* Space for icon to align text with other items */
    &::before {
      content: "";
      width: 24px;
      flex-shrink: 0;
    }
    color: var(--text-tertiary);

    & .icon {
      opacity: 0.7;
    }

    &::before {
      display: none;
    }
  }
}

.collapsed-divider {
  font-size: 1.2rem;
  font-weight: bold;

  display: none;
}

.sidebar-footer {
  margin-top: auto;
  padding: var(--spacing-xs);

  border-top: 1px solid var(--border-subtle);
}

/* ==================== MAIN CONTENT ==================== */
.main-content {
  display: flex;
  flex-direction: column;
  flex: 1;
  position: relative;
  padding: var(--spacing-md) var(--spacing-xl);
  overflow-y: auto;
  scrollbar-gutter: stable;
  transition:
    margin-left var(--duration-normal) var(--ease-decelerate),
    margin-right var(--duration-normal) var(--ease-decelerate);

  background: transparent;

  @media (min-width: 769px) {
    &.right-sidebar-open {
      margin-right: var(--right-sidebar-width);
    }
  }
}

/* ==================== TOP BAR ==================== */
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: var(--top-bar-offset, 0);
  z-index: 100;
  padding: var(--spacing-sm) var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
  gap: var(--spacing-md);
  border-radius: var(--radius-lg);

  background: var(--card-bg);
  backdrop-filter: blur(var(--acrylic-blur));
  -webkit-backdrop-filter: blur(var(--acrylic-blur));
  border: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-default);
  box-shadow: var(--shadow-sm);
  transition: top var(--duration-normal) var(--ease-standard);
}

.header-left h2 {
  font-size: var(--font-size-title);
  font-weight: 600;
  letter-spacing: -0.02em;

  margin: 0;

  color: var(--text-primary);
}

.controls {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* ==================== ADDITIONAL LAYOUT COMPONENTS ==================== */
.mobile-subject-btn {
  font: inherit;
  text-decoration: none;

  display: flex !important;
  align-items: center;
  max-width: 100%;
  padding: 4px 8px;
  gap: 8px;
  cursor: pointer;
  overflow: hidden;
  transition: all var(--duration-fast);

  background: none;
  border: none;
  border-radius: var(--radius-md);
  color: inherit;

  &:hover {
    background: var(--card-bg-hover);
  }
}

.mobile-subject-text {
  font-weight: 600;
  font-size: 0.9rem;
  text-transform: uppercase;
  white-space: nowrap;

  flex-shrink: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;

  color: var(--accent-default);
}

.top-bar-counters {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  flex-shrink: 0;
}

.completion-text {
  font-weight: 600;
}

.completion-label {
  font-size: 12px;

  color: var(--text-tertiary);
}

.accuracy-container {
  display: flex;
  align-items: center;
  flex: 1;
  min-width: 100px;
  gap: var(--spacing-xs);
}

.controls-wrapper {
  flex-shrink: 0;
}

.navigate-header {
  display: flex;
  align-items: center;
  flex: 1;
  gap: 10px;
}

#header-spacer {
  width: 100%;
  flex-shrink: 0;
}

/* ==================== RIGHT SIDEBAR ==================== */
.right-sidebar {
  display: flex;
  flex-direction: column;
  position: fixed;
  right: 0;
  top: 0;
  z-index: 1050; /* Above top bar (100) */
  height: 100vh;
  width: var(--right-sidebar-width);
  transform: translateX(100%);
  visibility: hidden;
  pointer-events: none;
  transition:
    transform var(--duration-slow) var(--ease-decelerate),
    visibility var(--duration-slow);

  background: var(--acrylic-bg);
  backdrop-filter: blur(var(--acrylic-blur)) saturate(120%);
  -webkit-backdrop-filter: blur(var(--acrylic-blur)) saturate(120%);
  border-left: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-xl);

  &.open {
    transform: translateX(0);
    visibility: visible;
    pointer-events: all;
  }
}

.right-sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: var(--header-height);
  padding: var(--spacing-md) var(--spacing-lg);
  gap: var(--spacing-md);

  border-bottom: 1px solid var(--border-subtle);

  & h3 {
    font-size: var(--font-size-subtitle);
    font-weight: 600;

    margin: 0;
  }
}

.sidebar-input {
  font-family: inherit;
  font-size: var(--font-size-body);
  text-align: center;

  min-width: 48px;
  width: 48px;
  padding: var(--spacing-xs) var(--spacing-sm);
  transition: all var(--duration-fast);

  background: var(--card-bg);
  border: 1px solid var(--border-subtle);
  border-bottom: 2px solid var(--border-default);
  border-radius: var(--radius-md);
  color: var(--text-primary);

  &:hover {
    background: var(--card-bg-hover);
    border-bottom-color: var(--border-strong);
  }

  &:focus {
    background: var(--card-bg-hover);
    border-bottom-color: var(--accent-default);
    outline: none;
  }
}

/* ==================== QUESTION GRID ==================== */
.grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(42px, 1fr));
  padding: var(--spacing-md);
  gap: 6px;
  overflow-y: auto;
  padding-bottom: 80px;
}

.grid-item {
  font-size: var(--font-size-caption);
  font-weight: 500;

  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-standard);

  background: var(--card-bg);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  color: var(--text-secondary);

  &:hover {
    transform: scale(1.08);

    background: var(--card-bg-hover);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
  }

  &.current {
    font-weight: 600;

    background: var(--accent-default);
    color: var(--text-on-accent);
    box-shadow: 0 0 12px var(--accent-glow);
  }

  &.correct {
    background: var(--success-default);
    color: var(--text-on-accent);
  }

  &.incorrect {
    background: var(--error-default);
    color: #fff;
  }

  &.marked {
    border: 2px solid var(--warning-default);
    box-shadow: 0 0 8px var(--warning-bg);
  }
}