/* ============================================================
   VIDYARTHIASTRA — MOBILE OVERRIDES & CAPACITOR NATIVE UI STYLES
   ============================================================ */

/* 1. Safe Area Insets for Android Status Bar & Navigation Bar */
:root {
  --sat: env(safe-area-inset-top, 0px);
  --sab: env(safe-area-inset-bottom, 0px);
  --sal: env(safe-area-inset-left, 0px);
  --sar: env(safe-area-inset-right, 0px);
}

body {
  padding-top: var(--sat);
  padding-bottom: var(--sab);
  padding-left: var(--sal);
  padding-right: var(--sar);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

/* 2. Header & Safe Area Adjustments */
.site-header {
  padding-top: calc(12px + var(--sat));
  max-width: 100%;
  min-width: 0;
}

.header-inner {
  max-width: 100%;
  min-width: 0;
}

@media (max-width: 768px) {
  .header-inner {
    padding-left: 16px;
    padding-right: 16px;
    gap: 12px;
  }

  .logo {
    font-size: 20px;
    flex-shrink: 0;
  }

  .brand-logo-img {
    height: 30px;
    max-width: 145px;
  }

  .nav {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    flex-wrap: nowrap;
    gap: 16px;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    max-width: 100%;
    min-width: 0;
    width: 100%;
    box-sizing: border-box;
    padding: 4px 18px 6px 18px;
  }

  .nav::-webkit-scrollbar {
    display: none;
  }

  .nav a {
    flex: 0 0 auto;
    flex-shrink: 0;
    white-space: nowrap;
  }

  .nav a:not(.profile-circle):not(.auth-button) {
    font-size: 14.5px;
    padding: 4px 6px;
  }
}

/* 3. Touch Targets (Min 44px height & width for inputs and primary buttons) */
button:not(.forgot-password):not(.auth-modal-close):not(.auth-tab):not(.modal-auth-switch button):not(.profile-circle):not(.ai-clear-btn):not(.live-refresh-btn):not(.ai-suggestion-chip):not(.live-category-chip):not(.floating-chatbot-btn), 
.btn, 
.primary-btn, 
.google-btn, 
.auth-button, 
input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
textarea {
  min-height: 46px;
  font-size: 16px !important; /* Prevents auto-zoom on WebView input focus */
  border-radius: 12px;
}

button:active, 
.btn:active, 
.exam-card:active, 
.year-card:active, 
.paper-card:active {
  transform: scale(0.98);
  transition: transform 0.1s ease;
}

/* 4. Search Box Mobile Responsiveness */
@media (max-width: 580px) {
  .search-box {
    flex-direction: column;
    gap: 10px;
    background: transparent;
    padding: 0;
    box-shadow: none;
    border: none;
  }

  .search-box input {
    width: 100%;
    border: 1px solid #cbd5e1;
    background: #ffffff;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.05);
  }

  .search-box button {
    width: 100%;
    min-height: 48px;
    border-radius: 12px;
  }
}

/* 5. Exam & Year Grids Mobile Adaptation */
@media (max-width: 640px) {
  .exam-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .exam-card {
    padding: 16px 18px;
  }

  .year-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .year-card {
    padding: 16px 12px;
  }
}

@media (max-width: 380px) {
  .year-grid {
    grid-template-columns: 1fr;
  }
}

/* 6. Papers List & Action Stacking on Small Screens */
@media (max-width: 768px) {
  .paper-list,
  .study-notes-list {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    box-sizing: border-box !important;
  }

  .paper-card {
    flex-direction: column !important;
    align-items: stretch !important;
    gap: 14px !important;
    padding: 16px !important;
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    box-sizing: border-box !important;
    overflow: hidden !important;
  }

  .paper-number {
    display: none !important;
  }

  .paper-icon {
    align-self: flex-start !important;
  }

  .paper-info {
    display: flex !important;
    flex-direction: column !important;
    align-items: flex-start !important;
    gap: 8px !important;
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    box-sizing: border-box !important;
  }

  .paper-info h3 {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    word-break: break-word !important;
    overflow-wrap: break-word !important;
    font-size: 16px !important;
    line-height: 1.35 !important;
    margin: 0 !important;
  }

  .paper-meta {
    display: flex !important;
    flex-wrap: wrap !important;
    align-items: center !important;
    gap: 6px !important;
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    box-sizing: border-box !important;
  }

  .paper-meta-item,
  .paper-stat-item {
    font-size: 12.5px !important;
    padding: 4px 8px !important;
    max-width: 100% !important;
    box-sizing: border-box !important;
  }

  .paper-actions {
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    display: flex !important;
    flex-direction: row !important;
    gap: 10px !important;
    margin-top: 2px !important;
    box-sizing: border-box !important;
  }

  .paper-actions .btn,
  .paper-actions button {
    flex: 1 1 0% !important;
    width: 100% !important;
    min-width: 0 !important;
    min-height: 44px !important;
    text-align: center !important;
    justify-content: center !important;
    font-size: 14px !important;
    padding: 10px 12px !important;
    box-sizing: border-box !important;
    white-space: nowrap !important;
  }
}

@media (max-width: 360px) {
  .paper-card {
    padding: 14px 12px !important;
    gap: 12px !important;
  }

  .paper-actions {
    flex-direction: column !important;
    gap: 8px !important;
  }

  .paper-actions .btn,
  .paper-actions button {
    flex: none !important;
    width: 100% !important;
  }
}

/* 7. PDF Viewer Fullscreen Overlay for Native Mobile */
.pdf-viewer {
  position: fixed;
  inset: 0;
  width: 100vw;
  height: 100vh;
  z-index: 10000;
  background: #0f172a;
  display: flex;
  flex-direction: column;
}

.pdf-viewer.hidden {
  display: none !important;
}

.pdf-viewer-header {
  min-height: 56px;
  padding: 8px 12px;
  background: #1e293b;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  border-bottom: 1px solid #334155;
  padding-top: calc(8px + var(--sat));
}

.pdf-viewer-title {
  color: #f8fafc;
  font-weight: 600;
  font-size: 15px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 28%;
}

.pdf-zoom-toolbar {
  display: flex;
  align-items: center;
  gap: 3px;
  background: rgba(255, 255, 255, 0.1);
  padding: 2px 4px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.pdf-zoom-toolbar .zoom-btn,
.pdf-zoom-toolbar .zoom-level-btn,
.pdf-zoom-toolbar .zoom-fit-btn {
  color: #f8fafc;
  background: transparent;
  min-width: 28px;
  height: 28px;
  font-size: 12px;
  padding: 2px 6px;
  border-radius: 4px;
}

.pdf-zoom-toolbar .zoom-btn:hover,
.pdf-zoom-toolbar .zoom-level-btn:hover,
.pdf-zoom-toolbar .zoom-fit-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.pdf-zoom-toolbar .zoom-level-btn {
  background: rgba(255, 255, 255, 0.15);
  min-width: 40px;
}

@media (max-width: 480px) {
  .pdf-viewer-title {
    display: none; /* Hide title text on narrow mobile screens to prioritize zoom toolbar */
  }

  .viewer-original {
    font-size: 11px;
    padding: 6px 8px;
  }

  .pdf-zoom-toolbar {
    gap: 2px;
    padding: 2px 3px;
  }
}

.pdf-viewer-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.viewer-original {
  padding: 8px 12px;
  background: #2563eb;
  color: #ffffff;
  border-radius: 8px;
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
}

.viewer-close {
  background: rgba(255, 255, 255, 0.15);
  color: #ffffff;
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.pdf-viewer-body {
  flex: 1;
  width: 100%;
  height: calc(100% - 60px);
  background: #ffffff;
}

.pdf-viewer-body iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* 8. Auth Modal Mobile Optimization */
@media (max-width: 600px) {
  .auth-modal {
    touch-action: none !important;
    overflow: hidden !important;
  }

  .auth-modal-card {
    width: min(390px, calc(100vw - 28px)) !important;
    max-width: calc(100vw - 28px) !important;
    max-height: calc(100dvh - 32px) !important;
    padding: 20px 16px !important;
    border-radius: 16px !important;
    overflow-y: auto !important;
    overflow-x: hidden !important;
    touch-action: pan-y !important;
    box-sizing: border-box !important;
    margin: auto !important;
  }
  
  .auth-modal-form label {
    box-sizing: border-box;
    width: 100%;
  }

  .auth-modal-form input {
    box-sizing: border-box;
    width: 100%;
    height: 44px !important;
    min-height: 44px !important;
    font-size: 16px !important; /* Prevents auto-zoom on iOS/Android WebView focus */
  }

  .auth-modal-header h2 {
    font-size: 19px !important;
  }
}

/* 9. PDF.js Inline Canvas & State Messaging */
.pdf-state-msg {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 280px;
  padding: 24px;
  text-align: center;
  color: #f8fafc;
  background: #0f172a;
}

.pdf-state-msg.hidden {
  display: none !important;
}

.pdf-spinner {
  width: 44px;
  height: 44px;
  border: 4px solid rgba(255, 255, 255, 0.2);
  border-top-color: #2563eb;
  border-radius: 50%;
  animation: pdf-spin 0.8s linear infinite;
  margin-bottom: 16px;
}

@keyframes pdf-spin {
  to {
    transform: rotate(360deg);
  }
}

.pdf-error-icon {
  font-size: 38px;
  margin-bottom: 10px;
}

.pdf-state-msg h4 {
  font-size: 18px;
  margin-bottom: 8px;
  color: #f8fafc;
}

.pdf-state-msg p {
  font-size: 14px;
  color: #94a3b8;
  margin-bottom: 18px;
}

.pdf-canvas-container {
  width: 100%;
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 14px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  background: #334155;
  -webkit-overflow-scrolling: touch;
}

.pdf-canvas-container:empty {
  display: none;
}

.pdf-page-wrapper {
  position: relative;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
  background: #ffffff;
  border-radius: 6px;
  overflow: hidden;
  width: 100%;
  max-width: 760px;
  margin: 0 auto;
}

.pdf-page-canvas {
  display: block !important;
  max-width: 100% !important;
  margin: 0 auto !important;
  height: unset !important;
  aspect-ratio: auto !important;
}

.pdf-page-number {
  text-align: center;
  font-size: 12px;
  font-weight: 600;
  color: #94a3b8;
  padding: 8px;
  background: #1e293b;
  border-top: 1px solid #334155;
}

.pdf-error-actions {
  display: flex;
  gap: 12px;
  margin-top: 14px;
  flex-wrap: wrap;
  justify-content: center;
}

.pdf-btn-primary {
  padding: 10px 18px;
  border-radius: 10px;
  background: #2563eb;
  color: #ffffff;
  border: none;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
}

.pdf-btn-secondary {
  padding: 10px 18px;
  border-radius: 10px;
  background: #334155;
  color: #ffffff;
  border: 1px solid #475569;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
}