/* ============================================================
   Songbook — Stile principale
   ============================================================ */

/* === RESET & CUSTOM PROPERTIES === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg:         #ffffff;
  --color-surface:    #f5f5f5;
  --color-surface2:   #e8e8e8;
  --color-accent:     #4A90E2;
  --color-accent-h:   #357ABD;
  --color-danger:     #e74c3c;
  --color-danger-h:   #c0392b;
  --color-text:       #1a1a1a;
  --color-text-dim:   #666666;
  --color-border:     rgba(0,0,0,0.1);
  --color-hover:      rgba(0,0,0,0.04);

  --sidebar-width:    240px;
  --topbar-height:    56px;
  --viewer-footer-h:  64px;
  --radius:           10px;
  --radius-sm:        6px;
  --shadow:           0 4px 24px rgba(0,0,0,0.4);
  --transition:       0.18s ease;

  --safe-top:    env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left:   env(safe-area-inset-left, 0px);
  --safe-right:  env(safe-area-inset-right, 0px);
}

html, body {
  height: 100%;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
  color-scheme: light;
}

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

/* === SIDEBAR === */
.sidebar {
  width: var(--sidebar-width);
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  padding-top: var(--safe-top);
  padding-left: var(--safe-left);
  transition: transform var(--transition);
  z-index: 100;
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 16px 12px;
  border-bottom: 1px solid var(--color-border);
}
.app-logo { font-size: 22px; }
.app-title { font-size: 18px; font-weight: 700; flex: 1; letter-spacing: -0.3px; }
.sidebar-close { display: none; }

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 8px 0;
  overscroll-behavior: contain;
}

#folder-list {
  list-style: none;
}
#folder-list li { position: relative; }

.folder-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 16px;
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  font-size: 14px;
  border-radius: 0;
  text-align: left;
  transition: background var(--transition);
  position: relative;
}
.folder-item:hover { background: var(--color-hover); }
.folder-item.active {
  background: rgba(74,144,226,0.18);
  color: #fff;
  font-weight: 600;
}
.folder-item.active::before {
  content: '';
  position: absolute;
  left: 0; top: 4px; bottom: 4px;
  width: 3px;
  background: var(--color-accent);
  border-radius: 0 3px 3px 0;
}
.folder-icon { font-size: 16px; flex-shrink: 0; }
.folder-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.folder-count {
  font-size: 12px;
  color: var(--color-text-dim);
  background: rgba(0,0,0,0.07);
  border-radius: 10px;
  padding: 1px 7px;
  flex-shrink: 0;
}
.folder-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

.folder-actions {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  display: none;
  gap: 2px;
}
#folder-list li:hover .folder-actions { display: flex; }

.sidebar-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--color-border);
  padding-bottom: calc(12px + var(--safe-bottom));
}

/* === MAIN === */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
}

/* === TOPBAR === */
.topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  height: var(--topbar-height);
  padding: 0 16px;
  padding-top: var(--safe-top);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

#btn-menu { display: none; }

.search-wrapper {
  flex: 1;
}
.search-input {
  width: 100%;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  padding: 7px 14px;
  color: var(--color-text);
  font-size: 14px;
  outline: none;
  transition: border-color var(--transition);
}
.search-input:focus { border-color: var(--color-accent); }
.search-input::placeholder { color: var(--color-text-dim); }

/* === DROP OVERLAY === */
.drop-overlay {
  position: absolute;
  inset: 0;
  background: rgba(74,144,226,0.25);
  backdrop-filter: blur(4px);
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 3px dashed var(--color-accent);
  border-radius: var(--radius);
  pointer-events: none;
}
.drop-overlay[hidden] { display: none !important; }
.drop-message { text-align: center; }
.drop-icon { font-size: 48px; }
.drop-message p { font-size: 20px; font-weight: 600; margin-top: 12px; }

/* === PDF SECTION === */
.pdf-section {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 20px 20px calc(20px + var(--safe-bottom));
  position: relative;
  overscroll-behavior: contain;
}

.section-heading {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 16px;
}
.section-heading h1 { font-size: 20px; font-weight: 700; }
.pdf-count-label { font-size: 13px; color: var(--color-text-dim); }

/* === PDF LIST === */
.pdf-grid {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.pdf-card {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  cursor: pointer;
  transition: background var(--transition);
  display: flex;
  flex-direction: row;
  align-items: center;
  padding: 14px 16px;
  position: relative;
  gap: 14px;
  min-height: 60px;
}
.pdf-card:first-child { border-top: 1px solid var(--color-border); }
.pdf-card:hover { background: var(--color-hover); }
.pdf-card:active { background: var(--color-surface2); }

.pdf-card-thumb {
  display: none; /* nascosta in vista lista */
}

.pdf-card-info {
  flex: 1;
  min-width: 0;
  background: none;
  padding: 0;
}
.pdf-card-name {
  font-size: 16px;
  font-weight: 500;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--color-text);
  margin-bottom: 4px;
}
.pdf-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.pdf-tag {
  font-size: 11px;
  padding: 2px 7px;
  border-radius: 4px;
  color: #fff;
  font-weight: 600;
  white-space: nowrap;
}

.pdf-card-menu-btn {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: none;
  border: none;
  color: var(--color-text-dim);
  font-size: 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition);
  flex-shrink: 0;
  opacity: 1;
}
.pdf-card-menu-btn:hover { background: var(--color-surface2); }

/* === EMPTY / LOADING STATE === */
.empty-state, .loading-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-text-dim);
}
.empty-icon { font-size: 48px; display: block; margin-bottom: 16px; }
.empty-sub { font-size: 13px; margin-top: 6px; }

/* === PDF VIEWER === */
.pdf-viewer {
  position: fixed;
  inset: 0;
  background: #000;
  z-index: 200;
  display: flex;
  flex-direction: column;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
}
.pdf-viewer[hidden] { display: none !important; }

.viewer-topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 12px;
  height: 50px;
  background: rgba(0,0,0,0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  flex-shrink: 0;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.viewer-title {
  flex: 1;
  font-size: 15px;
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.viewer-page-info { font-size: 13px; color: var(--color-text-dim); white-space: nowrap; }

.viewer-canvas-container {
  flex: 1;
  overflow: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  overscroll-behavior: contain;
  position: relative;
  background: #111;
}
.viewer-canvas-container canvas {
  max-width: 100%;
  display: block;
  box-shadow: 0 0 40px rgba(0,0,0,0.8);
}

.viewer-loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.6);
}

.viewer-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  height: var(--viewer-footer-h);
  background: rgba(0,0,0,0.8);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-top: 1px solid rgba(255,255,255,0.1);
  flex-shrink: 0;
  gap: 12px;
}
.viewer-page-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}
.page-input {
  width: 52px;
  text-align: center;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px;
  color: var(--color-text);
  font-size: 15px;
  -moz-appearance: textfield;
}
.page-input::-webkit-inner-spin-button,
.page-input::-webkit-outer-spin-button { -webkit-appearance: none; }
.page-total { font-size: 15px; color: var(--color-text-dim); }

.btn-nav {
  padding: 10px 20px;
  background: var(--color-surface2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  font-size: 18px;
  cursor: pointer;
  transition: background var(--transition);
  flex-shrink: 0;
}
.btn-nav:hover { background: var(--color-accent); }
.btn-nav:active { transform: scale(0.95); }
.btn-nav:disabled { opacity: 0.3; cursor: default; }

/* === MODALI === */
.modal {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 0;
}
.modal[hidden] { display: none !important; }

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(2px);
}

.modal-box {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius) var(--radius) 0 0;
  width: 100%;
  max-width: 560px;
  max-height: 90dvh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow);
  padding-bottom: var(--safe-bottom);
  animation: slideUp 0.22s ease;
}
.modal-box--sm { max-width: 380px; }

@keyframes slideUp {
  from { transform: translateY(30px); opacity: 0; }
  to   { transform: translateY(0);    opacity: 1; }
}

.modal-header {
  display: flex;
  align-items: center;
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}
.modal-header h3 { flex: 1; font-size: 17px; font-weight: 700; }
.modal-close { margin-left: 8px; }

.modal-body {
  flex: 1;
  overflow-y: auto;
  padding: 16px 20px;
  overscroll-behavior: contain;
}

.modal-footer {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  padding: 12px 20px 16px;
  border-top: 1px solid var(--color-border);
  flex-shrink: 0;
}
.modal-footer--spaced { justify-content: space-between; }

/* === UPLOAD === */
.upload-drop-zone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 30px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  font-size: 14px;
  color: var(--color-text-dim);
}
.upload-drop-zone.drag-over {
  border-color: var(--color-accent);
  background: rgba(74,144,226,0.1);
}
.upload-icon { font-size: 36px; display: block; margin-bottom: 8px; }
.upload-sub { margin: 6px 0 12px; font-size: 13px; }

.file-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 180px;
  overflow-y: auto;
}
.file-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
}
.file-item-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.file-item-size { color: var(--color-text-dim); white-space: nowrap; }
.file-item-remove { cursor: pointer; color: var(--color-danger); font-size: 16px; flex-shrink: 0; }

.upload-progress { margin-top: 16px; }
.progress-bar {
  height: 6px;
  background: var(--color-bg);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 8px;
}
.progress-fill {
  height: 100%;
  background: var(--color-accent);
  border-radius: 3px;
  width: 0%;
  transition: width 0.3s ease;
}
.progress-label { font-size: 13px; color: var(--color-text-dim); text-align: center; }

/* === CHIP LIST (selezione cartelle) === */
.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}
.chip {
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  color: #fff;
}
.chip.selected { border-color: rgba(255,255,255,0.7); filter: brightness(1.2); }
.chip:not(.selected) { opacity: 0.5; }

/* === COLOR PICKER === */
.color-picker { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }
.color-swatch {
  width: 30px; height: 30px;
  border-radius: 50%;
  cursor: pointer;
  border: 3px solid transparent;
  transition: border-color var(--transition), transform var(--transition);
}
.color-swatch.selected { border-color: #fff; transform: scale(1.2); }

/* === FORM === */
.form-group { margin-bottom: 14px; }
.form-group.mt { margin-top: 16px; }
.form-label { display: block; font-size: 13px; color: var(--color-text-dim); margin-bottom: 6px; font-weight: 600; }
.form-input {
  width: 100%;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  color: var(--color-text);
  font-size: 15px;
  outline: none;
  transition: border-color var(--transition);
}
.form-input:focus { border-color: var(--color-accent); }

.pdf-name-label {
  font-size: 16px;
  font-weight: 600;
  padding: 8px 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* === BUTTONS === */
.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
}
.btn-primary:hover { background: var(--color-accent-h); }
.btn-primary:active { transform: scale(0.97); }
.btn-primary:disabled { opacity: 0.4; cursor: default; }

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 9px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.btn-outline:hover { border-color: var(--color-accent); color: var(--color-accent); }
.btn-outline.w-full { width: 100%; }

.btn-danger {
  background: var(--color-danger);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
}
.btn-danger:hover { background: var(--color-danger-h); }

.btn-icon {
  background: none;
  border: none;
  color: var(--color-text);
  cursor: pointer;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  font-size: 18px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition);
  flex-shrink: 0;
}
.btn-icon:hover { background: var(--color-hover); }

.btn-icon-label { font-size: 20px; font-weight: 300; line-height: 1; }
.btn-text { font-size: 14px; }

/* === SPINNER === */
.spinner {
  width: 24px; height: 24px;
  border: 3px solid rgba(0,0,0,0.1);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 12px;
}
.spinner-large { width: 40px; height: 40px; border-width: 4px; }
@keyframes spin { to { transform: rotate(360deg); } }

/* === TOAST === */
.toast-container {
  position: fixed;
  bottom: calc(20px + var(--safe-bottom));
  left: 50%;
  transform: translateX(-50%);
  z-index: 500;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
  width: min(360px, 90vw);
}
.toast {
  background: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 14px;
  box-shadow: var(--shadow);
  animation: toastIn 0.25s ease;
  display: flex;
  align-items: center;
  gap: 10px;
}
.toast.toast-success { border-left: 4px solid #2ecc71; }
.toast.toast-error   { border-left: 4px solid var(--color-danger); }
.toast.toast-info    { border-left: 4px solid var(--color-accent); }
.toast-out { animation: toastOut 0.25s ease forwards; }
@keyframes toastIn  { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }
@keyframes toastOut { from { opacity: 1; } to { opacity: 0; transform: translateY(16px); } }

/* === UTILITY === */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* === RESPONSIVE MOBILE === */
@media (max-width: 640px) {
  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    transform: translateX(-100%);
    z-index: 200;
  }
  .sidebar.open { transform: translateX(0); box-shadow: var(--shadow); }
  .sidebar-close { display: flex; }

  #btn-menu { display: flex; }

  .pdf-card { padding: 12px 14px; }
  .pdf-card-name { font-size: 15px; }

  .modal-box {
    border-radius: var(--radius) var(--radius) 0 0;
  }

  .btn-text { display: none; }
  .btn-icon-label { font-size: 22px; }

  .viewer-footer { height: 58px; padding: 0 14px; }
  .btn-nav { padding: 8px 14px; font-size: 16px; }
}

/* === TABLET (iPad portrait) === */
@media (min-width: 641px) and (max-width: 1024px) {
  .sidebar { width: 200px; }
  .pdf-card-name { font-size: 17px; }
}

/* === LANDSCAPE MOBILE === */
@media (max-height: 500px) and (orientation: landscape) {
  .viewer-topbar { height: 42px; }
  .viewer-footer { height: 50px; }
}

/* === DARK MODE SYSTEM (already dark) === */
@media (prefers-color-scheme: light) {
  /* L'app è sempre dark per uso live */
}