/* ============================================================
   PDFFORGE — STYLESHEET
   Modern dark-themed PDF tool UI
============================================================ */

/* ---- CSS Custom Properties ---- */
:root {
  --bg-base:       #0d0f14;
  --bg-surface:    #161a23;
  --bg-card:       #1e2330;
  --bg-card-hover: #252c3d;
  --border:        #2e3547;
  --border-focus:  #4f6ef7;

  --accent:        #4f6ef7;
  --accent-light:  #6b86fa;
  --accent-glow:   rgba(79,110,247,0.25);
  --accent2:       #a855f7;

  --text-primary:  #f0f2f8;
  --text-secondary:#8b95b0;
  --text-muted:    #555e76;

  --danger:        #ef4444;
  --danger-bg:     rgba(239,68,68,0.12);
  --success:       #22c55e;
  --success-bg:    rgba(34,197,94,0.12);
  --warning:       #f59e0b;

  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  28px;

  --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 40px rgba(79,110,247,0.15);

  --font: 'Inter', system-ui, sans-serif;
  --transition: 0.2s ease;
}

/* ---- Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent); }

/* ============================================================
   HEADER
============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,15,20,0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-icon {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  color: #fff;
}
.logo-icon svg { width: 20px; height: 20px; }
.logo-text { font-size: 1.2rem; font-weight: 700; color: var(--text-primary); }
.logo-accent { color: var(--accent-light); }

.header-nav { display: flex; gap: 4px; }
.nav-link {
  padding: 8px 18px;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  background: none;
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-card); }
.nav-link.active { color: var(--accent-light); background: rgba(79,110,247,0.12); }

/* ============================================================
   MAIN WRAPPER
============================================================ */
.main-wrapper {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px 64px;
}

/* ============================================================
   PREMIUM AD CONTAINER
============================================================ */
.ad-placeholder {
  width: 100%;
  max-width: 800px; /* Neatly frames the 728px banner */
  min-height: 124px; /* 90px ad + padding */
  margin: 32px auto;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
  padding-top: 16px; /* Space for the label */
  transition: border-color var(--transition);
}
.ad-placeholder:hover {
  border-color: rgba(79,110,247,0.3);
}
.ad-placeholder::before {
  content: 'Advertisement';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-base);
  border: 1px solid var(--border);
  border-top: none;
  color: var(--text-muted);
  font-size: 0.65rem;
  padding: 2px 14px;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}
.ad-placeholder iframe {
  border: none !important;
  display: block;
  margin: 0 auto;
}

/* ============================================================
   HERO SECTION
============================================================ */
.hero-section {
  text-align: center;
  padding: 56px 0 40px;
}
.hero-badge {
  display: inline-block;
  background: rgba(79,110,247,0.15);
  border: 1px solid rgba(79,110,247,0.35);
  color: var(--accent-light);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 20px;
}
.hero-title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}
.gradient-text {
  background: linear-gradient(135deg, var(--accent-light), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 520px;
  margin: 0 auto 28px;
}
.hero-features { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.feature-pill {
  display: flex; align-items: center; gap: 7px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition);
}
.feature-pill svg { width: 15px; height: 15px; color: var(--accent-light); }
.feature-pill:hover { border-color: var(--accent); color: var(--text-primary); }

/* ============================================================
   TOOL CONTAINER
============================================================ */
.tool-container {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  box-shadow: var(--shadow-card), var(--shadow-glow);
  margin-bottom: 40px;
}

/* ============================================================
   API KEY BANNER (CONVERTERS)
============================================================ */
.api-key-banner {
  background: rgba(79,110,247,0.08);
  border: 1px solid rgba(79,110,247,0.2);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin-bottom: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.api-key-banner p {
  font-size: 0.9rem;
  color: var(--text-primary);
  line-height: 1.5;
}
.api-key-banner a {
  color: var(--accent-light);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}
.api-key-banner a:hover {
  color: var(--accent);
}
.api-key-input-group {
  position: relative;
  display: flex;
  align-items: center;
}
.api-key-input-group svg {
  position: absolute;
  left: 14px;
  width: 18px;
  height: 18px;
  color: var(--text-muted);
}
.api-key-input-group input {
  width: 100%;
  padding: 12px 16px 12px 42px;
  background: var(--bg-base);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.95rem;
  transition: all var(--transition);
}
.api-key-input-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* ============================================================
   UPLOAD / DROP ZONE
============================================================ */
.upload-area {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 56px 32px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  background: radial-gradient(ellipse at center, rgba(79,110,247,0.04) 0%, transparent 70%);
}
.upload-area:hover,
.upload-area.dragover {
  border-color: var(--accent);
  background: radial-gradient(ellipse at center, rgba(79,110,247,0.1) 0%, transparent 70%);
  box-shadow: 0 0 0 4px var(--accent-glow);
}
.upload-area.dragover { transform: scale(1.01); }

.upload-icon-wrap {
  position: relative;
  width: 80px; height: 80px;
  margin: 0 auto 24px;
}
.upload-icon-ring {
  position: absolute; inset: 0;
  border-radius: 50%;
  background: rgba(79,110,247,0.12);
  animation: pulse-ring 2.5s ease-in-out infinite;
}
.upload-icon {
  position: relative; z-index: 1;
  width: 80px; height: 80px;
  color: var(--accent-light);
  stroke-width: 1.5;
}
@keyframes pulse-ring {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50%       { transform: scale(1.15); opacity: 1; }
}

.upload-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; }
.upload-subtitle { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 24px; }
.upload-hint { color: var(--text-muted); font-size: 0.8rem; margin-top: 16px; }

/* ============================================================
   BUTTONS
============================================================ */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition);
  text-decoration: none;
  white-space: nowrap;
}
.btn svg { width: 16px; height: 16px; flex-shrink: 0; }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #3b5bd9);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(79,110,247,0.35);
}
.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-light), var(--accent));
  box-shadow: 0 6px 24px rgba(79,110,247,0.5);
  transform: translateY(-1px);
}
.btn-primary:active { transform: translateY(0); }

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border);
}
.btn-outline:hover { color: var(--text-primary); border-color: var(--text-secondary); background: var(--bg-card); }

.btn-ghost {
  background: var(--bg-card);
  color: var(--text-secondary);
  border-color: var(--border);
}
.btn-ghost:hover { color: var(--text-primary); background: var(--bg-card-hover); }

.btn-danger {
  background: var(--danger-bg);
  color: var(--danger);
  border-color: rgba(239,68,68,0.3);
}
.btn-danger:hover { background: rgba(239,68,68,0.2); }

.btn-large { padding: 13px 28px; font-size: 1rem; }

.btn-xs {
  padding: 4px 10px;
  font-size: 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  font-family: var(--font);
  font-weight: 600;
  transition: all var(--transition);
}
.btn-xs:hover { color: var(--text-primary); }

/* ============================================================
   FILE LIST (MERGE TAB)
============================================================ */
.file-list-section { margin-top: 8px; }

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.header-actions { display: flex; gap: 8px; align-items: center; }

.section-title { font-size: 1.15rem; font-weight: 700; }
.section-subtitle { color: var(--text-secondary); font-size: 0.85rem; margin-top: 2px; }

.file-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}

/* --- File Card --- */
.file-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  cursor: grab;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.file-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  opacity: 0;
  transition: opacity var(--transition);
}
.file-card:hover { border-color: var(--accent); box-shadow: 0 4px 20px rgba(79,110,247,0.15); }
.file-card:hover::before { opacity: 1; }
.file-card.sortable-chosen { cursor: grabbing; opacity: 0.85; box-shadow: 0 8px 32px rgba(0,0,0,0.5); }
.file-card.sortable-ghost { opacity: 0.3; }

.file-card-drag { color: var(--text-muted); display: flex; justify-content: center; margin-bottom: 4px; }
.file-card-drag svg { width: 18px; height: 18px; }

.file-thumb {
  width: 100%;
  aspect-ratio: 3/4;
  background: var(--bg-base);
  border-radius: var(--radius-sm);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.file-thumb canvas { max-width: 100%; max-height: 100%; object-fit: contain; }
.file-thumb-placeholder {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: var(--text-muted);
}
.file-thumb-placeholder svg { width: 40px; height: 40px; }

.file-info { flex: 1; }
.file-name {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary);
  word-break: break-word;
  line-height: 1.3;
}
.file-meta { font-size: 0.75rem; color: var(--text-muted); margin-top: 4px; }

.file-card-remove {
  width: 100%;
  padding: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-family: var(--font);
  transition: all var(--transition);
  display: flex; align-items: center; justify-content: center; gap: 5px;
}
.file-card-remove svg { width: 13px; height: 13px; }
.file-card-remove:hover { background: var(--danger-bg); color: var(--danger); border-color: rgba(239,68,68,0.25); }

/* ============================================================
   ACTION BAR
============================================================ */
.action-bar {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

/* ============================================================
   PAGES GRID (EDIT TAB)
============================================================ */
.pages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 16px;
  margin-bottom: 20px;
}

/* --- Page Card --- */
.page-card {
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  user-select: none;
}
.page-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,0.3); }
.page-card.marked-delete { border-color: var(--danger); opacity: 0.55; }
.page-card.marked-delete .page-thumb-wrap::after {
  content: '';
  position: absolute; inset: 0;
  background: rgba(239,68,68,0.2);
}

.delete-badge {
  position: absolute;
  top: 6px; right: 6px;
  background: var(--danger);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 100px;
  z-index: 2;
  letter-spacing: 0.04em;
  display: none;
}
.page-card.marked-delete .delete-badge { display: block; }

.page-thumb-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 3/4;
  background: var(--bg-base);
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.page-thumb-wrap canvas { max-width: 100%; max-height: 100%; object-fit: contain; }

.page-card-footer {
  padding: 8px 10px;
  display: flex; align-items: center; justify-content: space-between;
}
.page-number { font-size: 0.78rem; color: var(--text-secondary); font-weight: 600; }
.page-delete-hint { font-size: 0.68rem; color: var(--text-muted); }
.page-card.marked-delete .page-delete-hint { color: var(--danger); }

.deleted-info {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.25);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  font-size: 0.85rem;
  color: var(--warning);
}
.deleted-info svg { width: 16px; height: 16px; flex-shrink: 0; }

/* ============================================================
   HOW IT WORKS
============================================================ */
.how-it-works { padding: 40px 0; text-align: center; }
.section-heading {
  font-size: 1.6rem; font-weight: 700; margin-bottom: 32px;
  color: var(--text-primary);
}
.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.step-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: left;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.step-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  opacity: 0; transition: opacity var(--transition);
}
.step-card:hover { border-color: var(--accent); transform: translateY(-3px); box-shadow: var(--shadow-card); }
.step-card:hover::before { opacity: 1; }

.step-number {
  font-size: 2.5rem; font-weight: 800;
  color: rgba(79,110,247,0.15);
  line-height: 1; margin-bottom: 12px;
  letter-spacing: -0.02em;
}
.step-icon {
  width: 44px; height: 44px;
  background: rgba(79,110,247,0.1);
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  color: var(--accent-light);
  margin-bottom: 14px;
}
.step-icon svg { width: 22px; height: 22px; }
.step-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.step-card p { font-size: 0.88rem; color: var(--text-secondary); line-height: 1.6; }

/* ============================================================
   PROGRESS OVERLAY
============================================================ */
.progress-overlay {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(0,0,0,0.75);
  backdrop-filter: blur(6px);
  display: flex; align-items: center; justify-content: center;
}
.progress-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px;
  text-align: center;
  width: 340px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.6);
}
.progress-spinner {
  width: 56px; height: 56px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 20px;
}
@keyframes spin { to { transform: rotate(360deg); } }
.progress-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 6px; }
.progress-subtitle { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 20px; }
.progress-bar-track {
  height: 6px; background: var(--bg-card);
  border-radius: 3px; overflow: hidden;
}
.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 3px;
  transition: width 0.3s ease;
}

/* ============================================================
   TOAST NOTIFICATIONS
============================================================ */
.toast-container {
  position: fixed; bottom: 24px; right: 24px;
  z-index: 2000;
  display: flex; flex-direction: column; gap: 10px;
  pointer-events: none;
}
.toast {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  display: flex; align-items: center; gap: 10px;
  font-size: 0.88rem; font-weight: 500;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  animation: toast-in 0.3s ease;
  pointer-events: all;
  max-width: 340px;
}
@keyframes toast-in {
  from { opacity: 0; transform: translateX(20px); }
  to   { opacity: 1; transform: translateX(0); }
}
.toast-success { border-left: 3px solid var(--success); }
.toast-error   { border-left: 3px solid var(--danger); }
.toast-info    { border-left: 3px solid var(--accent); }
.toast svg { width: 18px; height: 18px; flex-shrink: 0; }
.toast-success svg { color: var(--success); }
.toast-error   svg { color: var(--danger); }
.toast-info    svg { color: var(--accent-light); }

/* ============================================================
   FOOTER
============================================================ */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: 24px;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
}
.footer-copy { font-size: 0.82rem; color: var(--text-muted); }

/* ============================================================
   THUMBNAIL LOADING SKELETON
============================================================ */
.thumb-skeleton {
  width: 100%; height: 100%;
  background: linear-gradient(90deg, var(--bg-card) 25%, var(--bg-card-hover) 50%, var(--bg-card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}
@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 640px) {
  .header-inner { padding: 0 16px; }
  .main-wrapper { padding: 0 16px 48px; }
  .tool-container { padding: 20px 16px; border-radius: var(--radius-lg); }
  .upload-area { padding: 36px 20px; }
  .hero-section { padding: 32px 0 28px; }
  .section-header { flex-direction: column; align-items: flex-start; }
  .action-bar { justify-content: stretch; }
  .action-bar .btn { flex: 1; justify-content: center; }
  .file-cards-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
  .pages-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); }
}