/* ============================================================
   styles/papers.css — Question Papers Browse & Upload Pages
   ============================================================ */

.papers-page {
  padding-top: calc(var(--navbar-h) + var(--sp-8));
}

/* ── Filter bar ──────────────────────────────────────────────── */
.filter-bar {
  display: flex; gap: var(--sp-3); align-items: center;
  flex-wrap: wrap; margin-bottom: var(--sp-6);
}
.filter-select {
  padding: 9px 14px; border-radius: var(--r-md);
  font-size: var(--text-sm); background: var(--bg-input);
  border: 1px solid var(--border); color: var(--text-primary);
  cursor: pointer; min-width: 140px;
}
.filter-select:focus { border-color: var(--border-focus); box-shadow: 0 0 0 3px rgba(124,58,237,0.12); }

.active-filters {
  display: flex; gap: var(--sp-2); flex-wrap: wrap; margin-bottom: var(--sp-4);
}
.active-filter {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  padding: 4px 12px; border-radius: var(--r-full);
  background: rgba(124,58,237,0.15); color: var(--brand-400);
  border: 1px solid rgba(124,58,237,0.25); font-size: var(--text-xs); font-weight: 500;
}
.active-filter button { background: none; border: none; color: inherit; cursor: pointer; font-size: 12px; }

/* ── Subject chips ───────────────────────────────────────────── */
.subject-chips {
  display: flex; gap: var(--sp-2); flex-wrap: wrap; margin-bottom: var(--sp-6);
}
.subject-chip {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  padding: 7px 16px; border-radius: var(--r-full);
  background: var(--bg-card); border: 1px solid var(--border);
  color: var(--text-secondary); font-size: var(--text-sm); font-weight: 500;
  cursor: pointer; transition: var(--t-fast); white-space: nowrap;
}
.subject-chip:hover { border-color: var(--border-brand); color: var(--brand-secondary); }
.subject-chip.active {
  background: rgba(124,58,237,0.15); border-color: var(--border-brand);
  color: var(--brand-secondary);
}
.subject-chip-icon { font-size: 16px; }
.subject-chip-count {
  font-size: 10px; background: var(--bg-card);
  padding: 1px 6px; border-radius: var(--r-full); color: var(--text-muted);
}

/* ── Paper grid ──────────────────────────────────────────────── */
.papers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--sp-4);
}

/* ── Paper Card & Production-Grade Action Buttons ────────────── */
.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  padding: var(--sp-4);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  position: relative;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), 
              border-color 0.25s ease, 
              box-shadow 0.25s ease;
  overflow: hidden;
}

.paper-card:hover {
  transform: translateY(-3px);
  border-color: rgba(124, 58, 237, 0.4);
  box-shadow: 0 12px 28px -6px rgba(0, 0, 0, 0.5), 0 0 16px rgba(124, 58, 237, 0.15);
}

.paper-thumb {
  position: relative;
  width: 100%;
  height: 160px;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--bg-input);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.paper-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.paper-tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: var(--r-full);
  font-size: 11px;
  font-weight: 600;
  background: rgba(124, 58, 237, 0.12);
  color: var(--brand-300, #c084fc);
  border: 1px solid rgba(124, 58, 237, 0.2);
}

.paper-title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.paper-subject {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  font-weight: 500;
}

/* ── Paper Card Actions Container ────────────────────────────── */
.paper-card-actions {
  display: flex !important;
  flex-direction: column !important;
  gap: 10px !important;
  margin-top: auto !important;
  padding-top: var(--sp-2) !important;
}

.paper-meta-strip {
  display: flex !important;
  align-items: center !important;
  justify-content: space-between !important;
  font-size: var(--text-xs) !important;
  color: var(--text-muted) !important;
  padding: 0 2px 2px 2px !important;
}

.paper-answers-badge {
  display: inline-flex !important;
  align-items: center !important;
  gap: 6px !important;
  color: var(--text-secondary) !important;
  font-size: 12px !important;
  font-weight: 500 !important;
}

.paper-answers-badge svg {
  color: var(--brand-400) !important;
}

/* Upper Row: PDF + Download Buttons */
.paper-action-row {
  display: grid !important;
  grid-template-columns: 1fr 1fr !important;
  gap: 8px !important;
  width: 100% !important;
}

/* Secondary Action Button (View PDF / Download) */
.paper-btn-secondary {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 7px !important;
  padding: 8px 12px !important;
  height: 38px !important;
  min-height: 38px !important;
  border-radius: var(--r-md) !important;
  font-size: 12.5px !important;
  font-weight: 600 !important;
  color: #ffffff !important;
  background: rgba(255, 255, 255, 0.06) !important;
  border: 1px solid rgba(255, 255, 255, 0.12) !important;
  backdrop-filter: blur(12px) !important;
  -webkit-backdrop-filter: blur(12px) !important;
  text-decoration: none !important;
  cursor: pointer !important;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1) !important;
  white-space: nowrap !important;
  user-select: none !important;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.25) !important;
}

.paper-btn-secondary svg {
  flex-shrink: 0 !important;
  color: var(--brand-300, #c084fc) !important;
  transition: transform 0.2s ease, color 0.2s ease !important;
}

.paper-btn-secondary:hover {
  background: rgba(124, 58, 237, 0.2) !important;
  border-color: rgba(124, 58, 237, 0.5) !important;
  color: #ffffff !important;
  transform: translateY(-1.5px) !important;
  box-shadow: 0 4px 14px rgba(124, 58, 237, 0.25) !important;
}

.paper-btn-secondary:hover svg {
  color: #ffffff !important;
  transform: scale(1.1) !important;
}

.paper-btn-secondary:active {
  transform: translateY(0) scale(0.98) !important;
}

.paper-btn-secondary.disabled {
  opacity: 0.35 !important;
  cursor: not-allowed !important;
  pointer-events: none !important;
  filter: grayscale(1) !important;
  background: rgba(255, 255, 255, 0.02) !important;
  border-color: rgba(255, 255, 255, 0.05) !important;
}

.paper-btn-secondary.is-downloading {
  opacity: 0.85 !important;
  cursor: wait !important;
  pointer-events: none !important;
  background: rgba(124, 58, 237, 0.15) !important;
  border-color: rgba(124, 58, 237, 0.4) !important;
}

.paper-btn-secondary.is-downloading svg {
  animation: spin 0.8s linear infinite !important;
  color: var(--brand-300, #c084fc) !important;
}

.paper-btn-secondary.is-downloaded {
  background: rgba(16, 185, 129, 0.2) !important;
  border-color: rgba(16, 185, 129, 0.5) !important;
  color: #34d399 !important;
}

.paper-btn-secondary.is-downloaded svg {
  color: #34d399 !important;
}

/* Bottom Row: Full-width Primary Upload CTA (Sits down) */
.paper-btn-upload {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 8px !important;
  width: 100% !important;
  height: 42px !important;
  min-height: 42px !important;
  padding: 10px 18px !important;
  border-radius: var(--r-md) !important;
  font-size: 13.5px !important;
  font-weight: 700 !important;
  letter-spacing: 0.3px !important;
  color: #ffffff !important;
  background: linear-gradient(135deg, #7c3aed 0%, #9333ea 50%, #a855f7 100%) !important;
  border: 1px solid rgba(255, 255, 255, 0.25) !important;
  text-decoration: none !important;
  cursor: pointer !important;
  position: relative !important;
  overflow: hidden !important;
  box-shadow: 0 4px 16px rgba(124, 58, 237, 0.45), inset 0 1px 0 rgba(255, 255, 255, 0.25) !important;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1) !important;
  user-select: none !important;
}

.paper-btn-upload::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0) 100%);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.paper-btn-upload:hover {
  transform: translateY(-2px) !important;
  box-shadow: 0 8px 24px rgba(124, 58, 237, 0.65), 0 0 16px rgba(168, 85, 247, 0.45) !important;
  border-color: rgba(255, 255, 255, 0.4) !important;
  color: #ffffff !important;
}

.paper-btn-upload:hover::before {
  opacity: 1;
}

.paper-btn-upload svg {
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

.paper-btn-upload:hover svg {
  transform: translateY(-2px);
}

.paper-btn-upload:active {
  transform: translateY(0) scale(0.985) !important;
  box-shadow: 0 2px 10px rgba(124, 58, 237, 0.35) !important;
}

.paper-btn-upload:focus-visible,
.paper-btn-secondary:focus-visible {
  outline: 2px solid var(--brand-400);
  outline-offset: 2px;
}

/* ── Upload flow ─────────────────────────────────────────────── */
.upload-page {
  padding-top: calc(var(--navbar-h) + var(--sp-8));
  max-width: 760px; margin: 0 auto;
}
.upload-steps {
  display: flex; gap: var(--sp-2); align-items: center;
  margin-bottom: var(--sp-8);
}
.upload-step {
  display: flex; align-items: center; gap: var(--sp-2);
  font-size: var(--text-sm); color: var(--text-muted);
}
.upload-step.active { color: var(--brand-secondary); font-weight: 600; }
.upload-step.done   { color: var(--success); }
.step-num {
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: var(--text-xs); font-weight: 700;
  background: var(--bg-card); border: 2px solid var(--border);
  transition: var(--t-base);
}
.upload-step.active .step-num { background: var(--brand-gradient); border-color: transparent; color: white; }
.upload-step.done .step-num   { background: var(--success-bg); border-color: var(--success); color: var(--success); }
.step-connector { flex: 1; height: 1px; background: var(--border); }

/* ── My uploads ─────────────────────────────────────────────── */
.my-uploads-page {
  padding-top: calc(var(--navbar-h) + var(--sp-8));
}
.uploads-list { display: flex; flex-direction: column; gap: var(--sp-3); }

/* ── Answer view ─────────────────────────────────────────────── */
.answer-view-page {
  padding-top: calc(var(--navbar-h) + var(--sp-8));
}
.answer-view-grid {
  display: grid; grid-template-columns: 1fr 360px;
  gap: var(--sp-6);
}
@media (max-width: 1000px) { .answer-view-grid { grid-template-columns: 1fr; } }

.answer-view-meta {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--r-xl); padding: var(--sp-6);
}
.answer-rating-section { margin: var(--sp-6) 0; padding: var(--sp-4) 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.avg-rating-display { display: flex; align-items: center; gap: var(--sp-3); margin-bottom: var(--sp-3); }
.avg-rating-num { font-size: var(--text-3xl); font-weight: 800; }
.avg-rating-count { font-size: var(--text-xs); color: var(--text-muted); }

/* ── Contributor Showcase Styles ─────────────────────────────── */
.answer-contributor-header-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  background: var(--surface-2);
  border: 1px solid var(--border-brand);
  border-radius: var(--r-full);
  padding: 4px 12px 4px 6px;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}
.answer-contributor-header-chip:hover {
  background: var(--surface-1);
  border-color: var(--brand-primary);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(124, 58, 237, 0.15);
}

.contributor-card {
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.contributor-card:hover {
  border-color: var(--brand-primary);
  box-shadow: 0 6px 24px rgba(124, 58, 237, 0.12);
}

.hover-underline {
  transition: color 0.15s ease, text-decoration 0.15s ease;
}
.hover-underline:hover {
  color: var(--brand-primary) !important;
  text-decoration: underline;
}

.contributor-hover-chip {
  padding: 3px 6px;
  margin: -3px -6px;
  border-radius: var(--r-md);
  transition: background 0.15s ease;
}
.contributor-hover-chip:hover {
  background: rgba(255, 255, 255, 0.05);
}

/* ── Paper view ──────────────────────────────────────────────── */
.paper-view-page {
  padding-top: calc(var(--navbar-h) + var(--sp-8));
}

/* ── Paper Card Copyright Attribution Badge ────────────────── */
.paper-copyright-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 9px;
  border-radius: var(--r-md);
  font-size: 11px;
  font-weight: 500;
  line-height: 1.3;
  width: fit-content;
  max-width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-secondary);
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  user-select: none;
}
.paper-copyright-badge svg {
  flex-shrink: 0;
  opacity: 0.85;
}
.paper-copyright-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.paper-copyright-badge.is-university {
  background: rgba(124, 58, 237, 0.08);
  border-color: rgba(124, 58, 237, 0.25);
  color: #c084fc;
}
.paper-copyright-badge.is-university svg {
  color: #c084fc;
}
.paper-copyright-badge.is-institution {
  background: rgba(6, 182, 212, 0.08);
  border-color: rgba(6, 182, 212, 0.25);
  color: #38bdf8;
}
.paper-copyright-badge.is-institution svg {
  color: #38bdf8;
}
.paper-card:hover .paper-copyright-badge.is-university {
  background: rgba(124, 58, 237, 0.16);
  border-color: rgba(124, 58, 237, 0.45);
}
.paper-card:hover .paper-copyright-badge.is-institution {
  background: rgba(6, 182, 212, 0.16);
  border-color: rgba(6, 182, 212, 0.45);
}

/* ── Owner Paper Form: Copyright Selection ─────────────────── */
.copyright-selector-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--sp-3);
  margin-top: var(--sp-2);
}

.copyright-option-card {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--r-lg);
  border: 1.5px solid var(--border);
  background: var(--surface-2);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  user-select: none;
}

.copyright-option-card input[type="radio"] {
  accent-color: var(--brand-primary);
  width: 17px;
  height: 17px;
  cursor: pointer;
  flex-shrink: 0;
}

.copyright-option-card:hover {
  border-color: rgba(124, 58, 237, 0.4);
  background: rgba(124, 58, 237, 0.03);
}

.copyright-option-card.active,
.copyright-option-card:has(input[type="radio"]:checked) {
  border-color: var(--brand-primary);
  background: rgba(124, 58, 237, 0.1);
  box-shadow: 0 0 16px rgba(124, 58, 237, 0.15);
}

.copyright-option-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.copyright-option-title {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.copyright-option-title svg {
  color: var(--brand-300);
}

.copyright-option-desc {
  font-size: 11px;
  color: var(--text-secondary);
}

/* ── Upload Form Card Preview Box ───────────────────────────── */
.form-preview-box {
  background: rgba(10, 10, 27, 0.6);
  border: 1px dashed var(--border);
  border-radius: var(--r-xl);
  padding: var(--sp-4);
  margin-top: var(--sp-4);
}

.form-preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-3);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ── Paper View Legal Notice Banner ──────────────────────────── */
.paper-view-copyright-banner {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  margin-top: var(--sp-4);
  border-radius: var(--r-md);
  background: rgba(124, 58, 237, 0.06);
  border: 1px solid rgba(124, 58, 237, 0.2);
  color: var(--text-secondary);
  font-size: var(--text-xs);
  line-height: 1.5;
}

.paper-view-copyright-banner svg {
  color: var(--brand-300);
  flex-shrink: 0;
  margin-top: 2px;
}

.paper-view-copyright-banner strong {
  color: var(--text-primary);
}

/* ── Mobile Overrides ────────────────────────────────────────── */
@media (max-width: 768px) {
  .paper-view-page, .papers-page, .upload-page, .my-uploads-page, .answer-view-page {
    padding-top: calc(var(--navbar-h) + var(--sp-4));
  }
}

@media (max-width: 600px) {
  .upload-steps { flex-direction: column; align-items: flex-start; gap: var(--sp-4); }
  .step-connector { display: none; }
  .upload-step { width: 100%; }
}