/* ============================================================
   HEADER
============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--clr-bg-white);
  border-bottom: 1px solid var(--clr-border);
  height: var(--header-height);
  box-shadow: 0 1px 0 rgba(0,0,0,.04);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Logo */
.site-branding {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.logo-mark {
  width: 36px;
  height: 36px;
  background: var(--clr-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.logo-mark::after {
  content: '';
  position: absolute;
  top: 0; right: 0;
  width: 50%; height: 50%;
  background: var(--clr-accent);
  border-radius: 0 0 0 50%;
}

.logo-mark svg {
  position: relative;
  z-index: 1;
  width: 20px;
  height: 20px;
  fill: white;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.logo-name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--clr-dark);
  letter-spacing: -0.02em;
}

.logo-tagline {
  font-size: 0.68rem;
  color: var(--clr-text-muted);
  font-weight: 400;
  letter-spacing: 0.03em;
}

/* Primary Nav */
.primary-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  flex: 1;
}

.primary-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--clr-text-muted);
  white-space: nowrap;
  transition: all var(--transition);
}

.primary-nav a:hover,
.primary-nav a.current {
  color: var(--clr-primary);
  background: rgba(11,79,138,.06);
}

.primary-nav a svg {
  width: 16px;
  height: 16px;
  opacity: 0.7;
}

/* Header Search */
.header-search {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 1;
  max-width: 380px;
}

.header-search-form {
  position: relative;
  flex: 1;
}

.header-search-input {
  width: 100%;
  height: 40px;
  padding: 0 var(--space-4) 0 40px;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-full);
  background: var(--clr-bg);
  font-size: 0.875rem;
  color: var(--clr-text);
  transition: all var(--transition);
  outline: none;
}

.header-search-input:focus {
  border-color: var(--clr-primary);
  background: white;
  box-shadow: 0 0 0 3px rgba(11,79,138,.08);
}

.header-search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--clr-text-muted);
  pointer-events: none;
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

.btn-menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--clr-text);
  border: 1.5px solid var(--clr-border);
  transition: all var(--transition);
}

.btn-menu-toggle:hover {
  background: var(--clr-bg);
  border-color: var(--clr-primary);
  color: var(--clr-primary);
}

.btn-menu-toggle svg {
  width: 20px;
  height: 20px;
}

/* Mobile Menu Drawer */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 2000;
  pointer-events: none;
}

.mobile-menu.open {
  pointer-events: all;
}

.mobile-menu-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15,23,42,.5);
  opacity: 0;
  transition: opacity 300ms var(--ease-out);
  backdrop-filter: blur(4px);
}

.mobile-menu.open .mobile-menu-backdrop {
  opacity: 1;
}

.mobile-menu-drawer {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 300px;
  background: white;
  padding: var(--space-6);
  transform: translateX(100%);
  transition: transform 300ms var(--ease-out);
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
}

.mobile-menu.open .mobile-menu-drawer {
  transform: translateX(0);
}

.mobile-menu-close {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  margin-bottom: var(--space-6);
}

.mobile-menu-close button {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  border: 1.5px solid var(--clr-border);
  color: var(--clr-text-muted);
  transition: all var(--transition);
}

.mobile-menu-close button:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
}

.mobile-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.mobile-nav a {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: 500;
  color: var(--clr-text);
  transition: all var(--transition);
}

.mobile-nav a:hover,
.mobile-nav a.current {
  background: rgba(11,79,138,.06);
  color: var(--clr-primary);
}

/* ============================================================
   HERO SECTION
============================================================ */
.hero {
  background: linear-gradient(135deg, var(--clr-dark) 0%, var(--clr-primary) 60%, #1a6bb5 100%);
  padding: var(--space-20) 0 var(--space-24);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: 
    radial-gradient(ellipse 60% 80% at 80% 50%, rgba(0,194,168,.15) 0%, transparent 60%),
    radial-gradient(ellipse 40% 60% at 20% 80%, rgba(255,255,255,.04) 0%, transparent 50%);
}

.hero-grid-pattern {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(rgba(255,255,255,.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 780px;
  margin: 0 auto;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius-full);
  color: rgba(255,255,255,.85);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: var(--space-6);
}

.hero-eyebrow::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--clr-accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.3); }
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 800;
  color: white;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-5);
}

.hero h1 .highlight {
  color: var(--clr-accent);
  position: relative;
}

.hero-sub {
  font-size: 1.1rem;
  color: rgba(255,255,255,.7);
  max-width: 560px;
  margin: 0 auto var(--space-10);
  font-weight: 300;
}

/* Hero Search Box */
.hero-search {
  background: white;
  border-radius: var(--radius-xl);
  padding: var(--space-2);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  box-shadow: var(--shadow-xl);
  max-width: 660px;
  margin: 0 auto;
}

.hero-search-inner {
  display: flex;
  align-items: center;
  flex: 1;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
}

.hero-search-inner svg {
  width: 22px;
  height: 22px;
  color: var(--clr-text-muted);
  flex-shrink: 0;
}

.hero-search-input {
  flex: 1;
  border: none;
  outline: none;
  font-size: 1rem;
  color: var(--clr-text);
  background: transparent;
}

.hero-search-input::placeholder {
  color: var(--clr-text-muted);
}

.hero-search-btn {
  height: 50px;
  padding: 0 var(--space-8);
  background: var(--clr-primary);
  color: white;
  border-radius: calc(var(--radius-xl) - var(--space-2));
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-display);
  white-space: nowrap;
  transition: all var(--transition);
  flex-shrink: 0;
}

.hero-search-btn:hover {
  background: var(--clr-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-accent);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
  margin-top: var(--space-10);
}

.hero-stat {
  text-align: center;
}

.hero-stat-num {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: white;
  letter-spacing: -0.03em;
}

.hero-stat-label {
  font-size: 0.8rem;
  color: rgba(255,255,255,.55);
  font-weight: 400;
  margin-top: 2px;
}

.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: rgba(255,255,255,.15);
}

/* ============================================================
   NEW PAPERS BANNER
============================================================ */
.new-papers-bar {
  background: var(--clr-primary);
  padding: var(--space-3) 0;
  overflow: hidden;
}

.new-papers-scroll {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  animation: scroll-left 30s linear infinite;
  white-space: nowrap;
  width: max-content;
}

.new-papers-scroll:hover {
  animation-play-state: paused;
}

@keyframes scroll-left {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

.new-paper-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: rgba(255,255,255,.85);
  font-size: 0.82rem;
  font-weight: 500;
}

.new-paper-item .dot {
  width: 5px;
  height: 5px;
  background: var(--clr-accent);
  border-radius: 50%;
}

.new-paper-badge {
  padding: 1px 8px;
  background: var(--clr-accent);
  color: white;
  border-radius: var(--radius-full);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ============================================================
   SECTIONS COMMON
============================================================ */
.section {
  padding: var(--space-16) 0;
}

.section--tight {
  padding: var(--space-12) 0;
}

.section--white {
  background: var(--clr-bg-white);
}

.section-header {
  margin-bottom: var(--space-10);
}

.section-header--flex {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--clr-accent-dark);
  margin-bottom: var(--space-2);
}

.section-title {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: var(--clr-dark);
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: 1rem;
  color: var(--clr-text-muted);
  margin-top: var(--space-2);
  max-width: 500px;
}

.view-all-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--clr-primary);
  white-space: nowrap;
  transition: gap var(--transition);
}

.view-all-link:hover {
  gap: var(--space-3);
  color: var(--clr-primary-dark);
}

.view-all-link svg {
  width: 16px;
  height: 16px;
}

/* ============================================================
   GRADE / EXAM BOARD TABS
============================================================ */
.filter-tabs {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-bottom: var(--space-8);
}

.filter-tab {
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  border: 1.5px solid var(--clr-border);
  color: var(--clr-text-muted);
  background: white;
  cursor: pointer;
  transition: all var(--transition);
}

.filter-tab:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
  background: rgba(11,79,138,.04);
}

.filter-tab.active {
  background: var(--clr-primary);
  border-color: var(--clr-primary);
  color: white;
  box-shadow: var(--shadow-sm);
}

/* A–Z Alphabet Filter */
.az-filter {
  display: flex;
  align-items: center;
  gap: 3px;
  flex-wrap: wrap;
  margin-bottom: var(--space-8);
  padding: var(--space-4);
  background: white;
  border-radius: var(--radius-lg);
  border: 1px solid var(--clr-border);
}

.az-filter-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-right: var(--space-3);
  white-space: nowrap;
}

.az-btn {
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  font-family: var(--font-display);
  color: var(--clr-text-muted);
  border: 1px solid transparent;
  transition: all var(--transition);
}

.az-btn:hover {
  background: rgba(11,79,138,.06);
  color: var(--clr-primary);
  border-color: rgba(11,79,138,.15);
}

.az-btn.active {
  background: var(--clr-primary);
  color: white;
  border-color: var(--clr-primary);
}

.az-btn.disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

/* ============================================================
   SUBJECT GRID
============================================================ */
.subject-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-4);
}

.subject-card {
  background: white;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  position: relative;
  overflow: hidden;
  transition: all var(--transition);
  group: true;
}

.subject-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--card-color, var(--clr-primary));
  opacity: 0;
  transition: opacity var(--transition);
}

.subject-card:hover {
  border-color: var(--card-color, var(--clr-primary));
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.subject-card:hover::before {
  opacity: 1;
}

.subject-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg, rgba(11,79,138,.08));
  color: var(--card-color, var(--clr-primary));
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: -0.02em;
  flex-shrink: 0;
  transition: all var(--transition);
}

.subject-card:hover .subject-card-icon {
  background: var(--card-color, var(--clr-primary));
  color: white;
}

.subject-card-body {
  flex: 1;
}

.subject-card-name {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--clr-dark);
  line-height: 1.3;
  margin-bottom: var(--space-1);
}

.subject-card-code {
  font-size: 0.75rem;
  color: var(--clr-text-muted);
  font-weight: 400;
}

.subject-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--space-2);
}

.subject-card-count {
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  font-weight: 500;
}

.subject-card-arrow {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--clr-border-light);
  color: var(--clr-text-muted);
  transition: all var(--transition);
  flex-shrink: 0;
}

.subject-card:hover .subject-card-arrow {
  background: var(--card-color, var(--clr-primary));
  color: white;
  transform: translateX(2px);
}

.subject-card-arrow svg {
  width: 14px;
  height: 14px;
}

/* Letter group heading in subject list */
.letter-group {
  display: none;
}

.letter-group.visible {
  display: block;
}

.letter-heading {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--clr-primary);
  padding: var(--space-6) 0 var(--space-4);
  border-bottom: 2px solid var(--clr-border);
  margin-bottom: var(--space-5);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.letter-heading::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--clr-border);
}

/* ============================================================
   SUBJECT LIST (Alternative layout for archive pages)
============================================================ */
.subject-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.subject-list-item {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: white;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--clr-text);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.subject-list-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--card-color, var(--clr-primary));
  opacity: 0;
  transition: opacity var(--transition);
}

.subject-list-item:hover {
  border-color: var(--card-color, var(--clr-primary));
  box-shadow: var(--shadow-sm);
  transform: translateX(2px);
}

.subject-list-item:hover::before {
  opacity: 1;
}

.subject-list-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 0.95rem;
  background: var(--card-bg, rgba(11,79,138,.07));
  color: var(--card-color, var(--clr-primary));
  flex-shrink: 0;
}

.subject-list-name {
  flex: 1;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--clr-dark);
}

.subject-list-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.subject-list-count {
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  white-space: nowrap;
}

.subject-list-arrow {
  color: var(--clr-text-muted);
  transition: all var(--transition);
}

.subject-list-item:hover .subject-list-arrow {
  color: var(--clr-primary);
  transform: translateX(3px);
}

.subject-list-arrow svg {
  width: 18px;
  height: 18px;
}

/* ============================================================
   PAPER TABLE (Year listing inside subject pages)
============================================================ */
.papers-section {
  background: white;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.papers-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-5) var(--space-6);
  background: var(--clr-bg);
  border-bottom: 1.5px solid var(--clr-border);
}

.papers-section-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--clr-dark);
}

.papers-year-group {
  border-bottom: 1px solid var(--clr-border-light);
}

.papers-year-group:last-child {
  border-bottom: none;
}

.papers-year-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-6);
  cursor: pointer;
  user-select: none;
  transition: background var(--transition);
}

.papers-year-header:hover {
  background: var(--clr-bg);
}

.papers-year-label {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--clr-dark);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.papers-year-badge {
  font-size: 0.72rem;
  padding: 2px 8px;
  background: var(--clr-accent-light);
  color: var(--clr-accent-dark);
  border-radius: var(--radius-full);
  font-weight: 600;
}

.papers-year-badge.new {
  background: #fef3c7;
  color: #92400e;
}

.papers-year-toggle {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--clr-text-muted);
  transition: all var(--transition);
}

.papers-year-group.open .papers-year-toggle {
  color: var(--clr-primary);
  transform: rotate(180deg);
}

.papers-year-toggle svg {
  width: 16px;
  height: 16px;
}

.papers-year-body {
  display: none;
  padding: var(--space-2) var(--space-6) var(--space-5);
}

.papers-year-group.open .papers-year-body {
  display: block;
}

.paper-items {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-3);
}

.paper-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  background: var(--clr-bg);
  transition: all var(--transition);
}

.paper-item:hover {
  border-color: var(--clr-primary);
  background: white;
  box-shadow: var(--shadow-sm);
}

.paper-item-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.paper-item-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--clr-dark);
}

.paper-item-links {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-1);
  flex-wrap: wrap;
}

.paper-dl-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 4px var(--space-3);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  transition: all var(--transition);
  text-decoration: none;
}

.paper-dl-btn--paper {
  background: rgba(11,79,138,.08);
  color: var(--clr-primary);
  border: 1px solid rgba(11,79,138,.15);
}

.paper-dl-btn--paper:hover {
  background: var(--clr-primary);
  color: white;
  border-color: var(--clr-primary);
}

.paper-dl-btn--memo {
  background: var(--clr-accent-light);
  color: var(--clr-accent-dark);
  border: 1px solid rgba(0,194,168,.2);
}

.paper-dl-btn--memo:hover {
  background: var(--clr-accent);
  color: white;
  border-color: var(--clr-accent);
}

.paper-dl-btn svg {
  width: 12px;
  height: 12px;
}

/* ============================================================
   SEARCH RESULTS
============================================================ */
.search-results-header {
  padding: var(--space-8) 0 var(--space-6);
}

.search-results-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--clr-dark);
}

.search-results-title em {
  color: var(--clr-primary);
  font-style: normal;
}

.search-results-count {
  color: var(--clr-text-muted);
  font-size: 0.9rem;
  margin-top: var(--space-2);
}

.search-no-results {
  text-align: center;
  padding: var(--space-20) 0;
}

.search-no-results svg {
  width: 64px;
  height: 64px;
  color: var(--clr-border);
  margin: 0 auto var(--space-6);
}

.search-no-results h3 {
  font-size: 1.3rem;
  margin-bottom: var(--space-3);
}

.search-no-results p {
  color: var(--clr-text-muted);
}

/* Live search dropdown */
.search-dropdown {
  position: absolute;
  top: calc(100% + var(--space-2));
  left: 0;
  right: 0;
  background: white;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  z-index: 100;
  display: none;
}

.search-dropdown.visible {
  display: block;
}

.search-dropdown-section {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--clr-border-light);
}

.search-dropdown-section:last-child {
  border-bottom: none;
}

.search-dropdown-label {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--clr-text-muted);
  margin-bottom: var(--space-2);
}

.search-result-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--clr-text);
  transition: background var(--transition);
}

.search-result-item:hover {
  background: var(--clr-bg);
}

.search-result-item svg {
  width: 16px;
  height: 16px;
  color: var(--clr-text-muted);
  flex-shrink: 0;
}

.search-result-name {
  font-size: 0.875rem;
  font-weight: 500;
}

.search-result-meta {
  font-size: 0.75rem;
  color: var(--clr-text-muted);
  margin-left: auto;
}

/* ============================================================
   BREADCRUMB
============================================================ */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  padding: var(--space-4) 0;
  font-size: 0.82rem;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--clr-text-muted);
}

.breadcrumb-item a {
  color: var(--clr-text-muted);
  font-weight: 500;
}

.breadcrumb-item a:hover {
  color: var(--clr-primary);
}

.breadcrumb-item.current {
  color: var(--clr-text);
  font-weight: 600;
}

.breadcrumb-sep {
  color: var(--clr-border);
}

/* ============================================================
   PAGE HEADER (Archive/Subject pages)
============================================================ */
.page-header {
  background: white;
  border-bottom: 1.5px solid var(--clr-border);
  padding-bottom: var(--space-8);
  margin-bottom: var(--space-8);
}

.page-header-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-6);
  padding-top: var(--space-6);
}

.page-header-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg, rgba(11,79,138,.08));
  color: var(--card-color, var(--clr-primary));
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.4rem;
  flex-shrink: 0;
}

.page-header-content {
  flex: 1;
}

.page-header-content h1 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}

.page-header-meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.page-header-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.875rem;
  color: var(--clr-text-muted);
  font-weight: 500;
}

.page-header-meta-item svg {
  width: 16px;
  height: 16px;
}

/* ============================================================
   SIDEBAR
============================================================ */
.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-8);
  align-items: start;
}

.sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--space-6));
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.sidebar-widget {
  background: white;
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.sidebar-widget-header {
  padding: var(--space-4) var(--space-5);
  border-bottom: 1.5px solid var(--clr-border);
  background: var(--clr-bg);
}

.sidebar-widget-title {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--clr-dark);
}

.sidebar-widget-body {
  padding: var(--space-4) var(--space-5);
}

.sidebar-link-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.sidebar-link-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--clr-text);
  font-size: 0.875rem;
  transition: all var(--transition);
}

.sidebar-link-item:hover {
  background: rgba(11,79,138,.05);
  color: var(--clr-primary);
}

.sidebar-link-item.active {
  background: rgba(11,79,138,.08);
  color: var(--clr-primary);
  font-weight: 600;
}

.sidebar-link-count {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--clr-text-muted);
  background: var(--clr-border-light);
  padding: 1px 8px;
  border-radius: var(--radius-full);
}

/* ============================================================
   QUICK STATS WIDGET
============================================================ */
.quick-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
  padding: var(--space-5);
}

.quick-stat {
  text-align: center;
  padding: var(--space-4);
  background: var(--clr-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--clr-border);
}

.quick-stat-num {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--clr-primary);
  letter-spacing: -0.02em;
}

.quick-stat-label {
  font-size: 0.72rem;
  color: var(--clr-text-muted);
  font-weight: 500;
  margin-top: 2px;
}

/* ============================================================
   BUTTONS
============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-display);
  transition: all var(--transition);
  text-decoration: none;
  cursor: pointer;
  border: 1.5px solid transparent;
}

.btn svg {
  width: 18px;
  height: 18px;
}

.btn--primary {
  background: var(--clr-primary);
  color: white;
  border-color: var(--clr-primary);
}

.btn--primary:hover {
  background: var(--clr-primary-dark);
  border-color: var(--clr-primary-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn--accent {
  background: var(--clr-accent);
  color: white;
  border-color: var(--clr-accent);
}

.btn--accent:hover {
  background: var(--clr-accent-dark);
  border-color: var(--clr-accent-dark);
  color: white;
  box-shadow: var(--shadow-accent);
}

.btn--outline {
  background: transparent;
  color: var(--clr-primary);
  border-color: var(--clr-primary);
}

.btn--outline:hover {
  background: var(--clr-primary);
  color: white;
}

.btn--ghost {
  background: transparent;
  color: var(--clr-text-muted);
  border-color: var(--clr-border);
}

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

.btn--lg {
  padding: var(--space-4) var(--space-8);
  font-size: 1rem;
  border-radius: var(--radius-lg);
}

.btn--sm {
  padding: var(--space-2) var(--space-4);
  font-size: 0.82rem;
  border-radius: var(--radius-sm);
}

/* ============================================================
   PAGINATION
============================================================ */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-8) 0;
}

.page-num {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--clr-text-muted);
  border: 1.5px solid var(--clr-border);
  background: white;
  text-decoration: none;
  transition: all var(--transition);
}

.page-num:hover,
.page-num.current {
  background: var(--clr-primary);
  color: white;
  border-color: var(--clr-primary);
}

.page-num.dots {
  border: none;
  background: none;
  cursor: default;
}

/* ============================================================
   404 PAGE
============================================================ */
.error-404 {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-16) 0;
}

.error-404-code {
  font-family: var(--font-display);
  font-size: 8rem;
  font-weight: 800;
  color: var(--clr-border);
  line-height: 1;
  letter-spacing: -0.05em;
  margin-bottom: var(--space-4);
}

.error-404 h1 {
  font-size: 1.8rem;
  margin-bottom: var(--space-4);
}

.error-404 p {
  color: var(--clr-text-muted);
  margin-bottom: var(--space-8);
}

/* ============================================================
   FOOTER
============================================================ */
.site-footer {
  background: var(--clr-dark);
  color: rgba(255,255,255,.7);
  padding: var(--space-16) 0 0;
  margin-top: var(--space-20);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-10);
  padding-bottom: var(--space-12);
  border-bottom: 1px solid rgba(255,255,255,.08);
}

.footer-brand .logo-name {
  color: white;
}

.footer-brand .logo-tagline {
  color: rgba(255,255,255,.5);
}

.footer-desc {
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(255,255,255,.55);
  margin-top: var(--space-5);
  max-width: 300px;
}

.footer-col-title {
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 700;
  color: white;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-5);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links a {
  color: rgba(255,255,255,.55);
  font-size: 0.875rem;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--clr-accent);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-5) 0;
  font-size: 0.8rem;
  color: rgba(255,255,255,.35);
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-5);
}

.footer-bottom-links a {
  color: rgba(255,255,255,.35);
  transition: color var(--transition);
}

.footer-bottom-links a:hover {
  color: var(--clr-accent);
}

/* ============================================================
   LOADING STATE
============================================================ */
.skeleton {
  background: linear-gradient(90deg, var(--clr-border-light) 25%, var(--clr-border) 50%, var(--clr-border-light) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius-sm);
}

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ============================================================
   TOAST NOTIFICATIONS
============================================================ */
.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: 9000;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-5);
  background: var(--clr-dark);
  color: white;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.875rem;
  font-weight: 500;
  pointer-events: all;
  animation: toast-in 300ms var(--ease-out) forwards;
  max-width: 340px;
}

.toast.removing {
  animation: toast-out 200ms var(--ease-in) forwards;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateY(16px) scale(0.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes toast-out {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(8px) scale(0.95); }
}

.toast svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  color: var(--clr-accent);
}

/* ============================================================
   RESPONSIVE
============================================================ */
@media (max-width: 1024px) {
  .content-with-sidebar {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: static;
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 60px;
  }

  .primary-nav {
    display: none;
  }

  .header-search {
    max-width: none;
    flex: 1;
  }

  .btn-menu-toggle {
    display: flex;
  }

  .hero {
    padding: var(--space-12) 0 var(--space-16);
  }

  .hero-search {
    flex-direction: column;
    padding: var(--space-3);
  }

  .hero-search-btn {
    width: 100%;
    justify-content: center;
  }

  .hero-stats {
    gap: var(--space-5);
  }

  .hero-stat-num {
    font-size: 1.2rem;
  }

  .subject-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: var(--space-3);
  }

  .az-filter {
    padding: var(--space-3);
    gap: 2px;
  }

  .az-btn {
    width: 26px;
    height: 26px;
    font-size: 0.72rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: var(--space-3);
  }

  .sidebar {
    grid-template-columns: 1fr;
  }

  .page-header-inner {
    flex-direction: column;
  }

  .paper-items {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }

  .subject-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero-stats {
    gap: var(--space-4);
  }

  .hero-stat-divider {
    display: none;
  }

  .paper-items {
    grid-template-columns: 1fr;
  }
}

/* ============================================================
   PRINT
============================================================ */
@media print {
  .site-header,
  .site-footer,
  .sidebar,
  .filter-tabs,
  .az-filter,
  .hero { display: none !important; }
  
  body { background: white; color: black; }
  .papers-year-body { display: block !important; }
}

/* ============================================================
   SCROLL ANIMATIONS
============================================================ */
[data-animate] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 500ms var(--ease-out), transform 500ms var(--ease-out);
}

[data-animate].animated {
  opacity: 1;
  transform: translateY(0);
}

[data-animate-delay="1"] { transition-delay: 100ms; }
[data-animate-delay="2"] { transition-delay: 200ms; }
[data-animate-delay="3"] { transition-delay: 300ms; }
[data-animate-delay="4"] { transition-delay: 400ms; }
[data-animate-delay="5"] { transition-delay: 500ms; }