/* ==========================================================================
   MOBILE RESPONSIVE ENGINE: Files/mobile.css
   PURPOSE: Modern Pure-Flexbox Mobile Phone Layout (<= 768px).
   Positions tab switching buttons directly under the chat dock with zero
   floating offsets, zero off-screen drift, and zero empty bottom bars.
   Strictly under 200 lines in compliance with project rules.
   ========================================================================== */

@media (max-width: 768px) {
  /* 1. Root Document Flex Container (Locked to True Viewport Height) */
  html {
    height: 100% !important;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden !important;
  }

  body {
    display: flex !important;
    flex-direction: column !important;
    height: 100% !important;
    height: 100dvh !important;
    width: 100vw !important;
    margin: 0 !important;
    padding: 0 !important;
    overflow: hidden !important;
    background-color: var(--bg-canvas) !important;
  }

  /* 2. Main Workspace Container: Takes all remaining vertical space above nav */
  .tripane-container {
    display: flex !important;
    flex-direction: column !important;
    flex: 1 1 auto !important;
    height: 0 !important;
    min-height: 0 !important;
    width: 100vw !important;
    padding: 0 !important;
    margin: 0 !important;
    gap: 0 !important;
    overflow: hidden !important;
    position: relative !important;
  }

  .drag-splitter {
    display: none !important;
  }

  /* 3. Pane Stacks */
  .left-col-stack,
  .pane-center,
  .right-col-stack {
    display: none !important;
    flex: 1 1 auto !important;
    height: 100% !important;
    width: 100vw !important;
    min-height: 0 !important;
    padding: 0 !important;
    margin: 0 !important;
    box-sizing: border-box !important;
    overflow: hidden !important;
    border: none !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    background: transparent !important;
  }

  .left-col-stack.mobile-active,
  .pane-center.mobile-active,
  .right-col-stack.mobile-active {
    display: flex !important;
    flex-direction: column !important;
  }

  .pane-island {
    border: none !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    background: transparent !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
  }

  /* 4. CHAT TAB: Seamless Stream & Dock */
  .pane-center {
    padding: 0 !important;
  }

  .diary-mount-container {
    padding: 0 !important;
    flex: 1 1 auto !important;
    min-height: 0 !important;
    display: flex !important;
    flex-direction: column !important;
    overflow: hidden !important;
  }

  #diary-stream {
    flex: 1 1 auto !important;
    min-height: 0 !important;
    padding: 12px 14px 6px 14px !important;
    overflow-y: auto !important;
  }

  .chat-dock {
    flex-shrink: 0 !important;
    padding: 6px 10px 8px 10px !important;
    background: var(--surface-opaque) !important;
    border-top: 1px solid var(--border) !important;
    margin: 0 !important;
  }

  .chat-bubble-user {
    max-width: 86% !important;
    font-size: 14.5px !important;
    padding: 10px 14px !important;
  }

  .chat-bubble-bot {
    max-width: 92% !important;
    font-size: 14.5px !important;
    padding: 12px 15px !important;
  }

  /* 5. NOTEPAD & STAGES HEADERS */
  .right-top-box,
  .left-top-box {
    height: 44px !important;
    border-radius: 0 !important;
    border: none !important;
    border-bottom: 1.5px solid var(--border) !important;
    box-shadow: none !important;
    background: var(--surface-opaque) !important;
    padding: 0 12px !important;
  }

  .pane-right,
  .pane-left {
    flex: 1 1 auto !important;
    min-height: 0 !important;
    padding: 10px 12px !important;
    overflow-y: auto !important;
  }

  /* 6. Guaranteed-Visible Tab Switching Bar (Directly Under Chat Dock) */
  .mobile-nav-bar {
    display: flex !important;
    position: relative !important;
    flex-shrink: 0 !important;
    height: 48px !important;
    min-height: 48px !important;
    max-height: 48px !important;
    width: 100vw !important;
    background: var(--surface-opaque) !important;
    border-top: 1px solid var(--border) !important;
    z-index: 999999 !important;
    align-items: center !important;
    justify-content: space-around !important;
    padding: 0 !important;
    margin: 0 !important;
    box-sizing: border-box !important;
  }

  .mobile-nav-tab {
    display: flex !important;
    flex-direction: column !important;
    align-items: center !important;
    justify-content: center !important;
    background: transparent !important;
    border: none !important;
    color: var(--text-dim) !important;
    font-family: var(--font-sans) !important;
    font-size: 10px !important;
    font-weight: 700 !important;
    line-height: 1 !important;
    cursor: pointer !important;
    flex: 1 !important;
    height: 48px !important;
    padding: 0 !important;
    margin: 0 !important;
    gap: 2px !important;
    transition: color 0.15s ease !important;
  }

  .mobile-nav-tab.active {
    color: var(--text-main) !important;
  }

  .mobile-nav-tab span.material-symbols-rounded {
    font-size: 21px !important;
    line-height: 1 !important;
  }

  /* 7. Hold-to-Speak Touch Safeguards */
  #btn-diary-mic,
  #btn-review-mic {
    touch-action: none !important;
    -webkit-touch-callout: none !important;
    user-select: none !important;
  }
}

@media (min-width: 769px) {
  .mobile-nav-bar {
    display: none !important;
  }
}