/* ================================================================
   BASE.CSS
   İçindəkilər:
   - CSS dəyişənləri (:root)
   - Reset & body
   - Grid background
   - Container
   - Header & logo & lang toggle
   - Hero section
   - Breadcrumb & back button
   - Section label
   - Course cards
   - Tab bar
   - Subject cards
   - Stats
   - Semester başlığı
   - Animations (fadeUp, pulse)
   - Utility (.hidden)
   ================================================================ */

:root {
  --bg: #020a18;
  --surface: #061428;
  --surface2: #0a1e3a;
  --accent: #0066CC;
  --accent2: #4DA6FF;
  --accent3: #003087;
  --text: #e8eef8;
  --muted: #5a7a9e;
  --border: rgba(0,102,204,0.18);
  --glow: rgba(0,102,204,0.09);

  /* Section Heading Design Token */
  --sh-bar: 3px;
  --sh-bar-color: var(--accent);
  --sh-bar-radius: 2px;
  --sh-size: 0.68rem;
  --sh-weight: 800;
  --sh-spacing: 0.14em;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Arial Nova', 'Arial', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 10%, rgba(0,102,204,0.07) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(0,48,135,0.05) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

.grid-bg {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(0,102,204,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,102,204,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  z-index: 0;
}

.container {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px 100px;
}

/* ─── Container alt boşluq (navbar üçün) ───────────────────── */
.container {
  padding-bottom: 120px !important;
}

/* ─── Header ────────────────────────────────────────────────── */
header {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 20px 0;
  max-width: 1100px;
  margin: 0 auto;
}

.logo {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-weight: 800;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  background: linear-gradient(135deg, var(--accent2), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.lang-toggle { display: none; } /* header-right dropdown ilə əvəzləndi */

.lang-btn {
  padding: 6px 14px;
  font-size: 0.8rem;
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-weight: 600;
  letter-spacing: 0.05em;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--muted);
  transition: all 0.2s;
}

.lang-btn.active {
  background: var(--accent);
  color: white;
}

/* ─── Hero ──────────────────────────────────────────────────── */
.hero {
  text-align: center;
  padding: 60px 20px 50px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--glow);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 6px 16px;
  font-size: 0.75rem;
  color: var(--accent2);
  letter-spacing: 0.1em;
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero-badge::before {
  content: '●';
  font-size: 0.5rem;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

h1, h2 {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

h1 span, h2 span {
  background: linear-gradient(135deg, var(--accent), var(--accent2), var(--accent3));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  color: var(--muted);
  font-size: 1rem;
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ─── Breadcrumb ────────────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 32px;
  font-size: 0.85rem;
  color: var(--muted);
  flex-wrap: wrap;
}

.breadcrumb-item {
  cursor: pointer;
  color: var(--accent);
  transition: color 0.2s;
}

.breadcrumb-item:hover { color: var(--accent2); }
.breadcrumb-sep { color: var(--muted); opacity: 0.4; }
.breadcrumb-current { color: var(--text); }

/* ─── Back button ───────────────────────────────────────────── */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
  cursor: pointer;
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
  background: var(--glow);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 16px;
}

.back-btn:hover {
  background: var(--border);
  transform: translateX(-3px);
}

/* ─── Section Heading — Unified Design Code ─────────────────── */
/*     Use .section-label on any section heading across the app  */
.section-label,
.dash-section-title,
.timer-section-title,
.gpa-section-title,
.sidebar-section-label {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-size: var(--sh-size);
  font-weight: var(--sh-weight);
  letter-spacing: var(--sh-spacing);
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 16px;
  padding-left: 10px;
  border-left: var(--sh-bar) solid var(--sh-bar-color);
  border-radius: 0 var(--sh-bar-radius) var(--sh-bar-radius) 0;
  line-height: 1.4;
}

/* Sidebar section labels — tighter spacing */
.sidebar-section-label {
  margin-bottom: 10px;
  font-size: 0.65rem;
}

/* ─── Course Cards ──────────────────────────────────────────── */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.course-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 32px 24px;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.course-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--glow), rgba(6,182,212,0.03));
  opacity: 0;
  transition: opacity 0.3s;
}

.course-card:hover { transform: translateY(-6px) scale(1.01); border-color: var(--border); }
.course-card:hover::before { opacity: 1; }

.course-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
  display: block;
}

.course-card h3 {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.course-card .sub-count {
  font-size: 0.78rem;
  color: var(--muted);
}

.course-card .tag {
  display: inline-block;
  margin-top: 12px;
  padding: 3px 10px;
  background: var(--glow);
  border-radius: 100px;
  font-size: 0.7rem;
  color: var(--accent2);
  font-weight: 500;
}

/* ─── Tab Bar ───────────────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 6px;
  flex-wrap: wrap;
}

.tab-btn {
  flex: 1;
  min-width: 80px;
  padding: 10px 16px;
  border: none;
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font-size: 0.85rem;
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text);
  background: var(--surface2);
}

.tab-btn.active {
  background: var(--accent);
  color: white;
  box-shadow: 0 2px 10px rgba(59, 130, 246, 0.35);
}

/* ─── Subject Cards ─────────────────────────────────────────── */
.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
}

.subject-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  cursor: pointer;
  transition: all 0.25s;
  display: flex;
  align-items: center;
  gap: 14px;
  position: relative;
  overflow: hidden;
}

.subject-card::after {
  content: '›';
  position: absolute;
  right: 18px;
  font-size: 1.4rem;
  color: var(--muted);
  transition: all 0.25s;
}

.subject-card:hover { border-color: var(--border); background: var(--surface2); transform: translateX(4px); }
.subject-card:hover::after { color: var(--accent); right: 14px; }

.subject-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent3));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.subject-info { flex: 1; min-width: 0; padding-right: 20px; }
.subject-info h4 {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 4px;
}

.subject-info .pdf-count {
  font-size: 0.73rem;
  color: var(--muted);
}

.pdf-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: rgba(6,182,212,0.1);
  border: 1px solid rgba(6,182,212,0.2);
  border-radius: 6px;
  padding: 2px 7px;
  font-size: 0.68rem;
  color: var(--accent2);
  font-weight: 600;
}

/* ─── Stats ─────────────────────────────────────────────────── */
.stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.stat { text-align: center; }

.stat-num {
  font-family: 'Arial Nova', 'Nunito', 'Arial', sans-serif;
  font-size: 1.6rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.72rem;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* ─── Semester Başlığı ──────────────────────────────────────── */
.semester-header {
  grid-column: 1 / -1;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 18px 4px 8px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 4px;
}

.semester-header:first-child { padding-top: 4px; }

/* ─── Animations ────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fadeUp 0.4s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

.animate-in:nth-child(1) { animation-delay: 0ms; }
.animate-in:nth-child(2) { animation-delay: 60ms; }
.animate-in:nth-child(3) { animation-delay: 120ms; }
.animate-in:nth-child(4) { animation-delay: 180ms; }
.animate-in:nth-child(5) { animation-delay: 240ms; }
.animate-in:nth-child(6) { animation-delay: 300ms; }
.animate-in:nth-child(7) { animation-delay: 360ms; }
.animate-in:nth-child(8) { animation-delay: 420ms; }

/* ─── Ana Tab Sistemi ───────────────────────────────────────── */
.main-tab {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
}

.main-tab.active-tab {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}

/* ─── Utility ───────────────────────────────────────────────── */
.hidden { display: none !important; }

/* ─── Theme panel (köhnə — gizlədilmiş) ────────────────────── */
.theme-panel { display: none !important; }

/* ================================================================
   HOME v2 — BIG STAT CARDS + WHY SECTION + POPULAR MATERIALS
   ================================================================ */

/* ─── Hero v2 tweaks ─────────────────────────────────────────── */
.hero-v2 { padding-bottom: 0; }

.hero-badge-dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent2);
  animation: pulse 2s infinite;
  margin-right: 6px;
  vertical-align: middle;
}

/* ─── STAT CARDS GRID ────────────────────────────────────────── */
.stat-cards-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 36px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 600px) {
  .stat-cards-grid { grid-template-columns: repeat(4, 1fr); max-width: 820px; }
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 22px 16px 18px;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
  cursor: default;
}

.stat-card::before {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.22s;
  border-radius: 18px;
}

.stat-card:hover { transform: translateY(-4px); }
.stat-card:hover::before { opacity: 1; }

.stat-card--blue  { border-color: var(--border); }
.stat-card--blue::before  { background: radial-gradient(ellipse at 50% 0%, var(--glow) 0%, transparent 70%); }
.stat-card--blue:hover    { box-shadow: 0 12px 40px rgba(59,130,246,0.18); }

.stat-card--cyan  { border-color: rgba(6,182,212,0.35); }
.stat-card--cyan::before  { background: radial-gradient(ellipse at 50% 0%, rgba(6,182,212,0.12) 0%, transparent 70%); }
.stat-card--cyan:hover    { box-shadow: 0 12px 40px rgba(6,182,212,0.18); }

.stat-card--purple { border-color: rgba(139,92,246,0.35); }
.stat-card--purple::before { background: radial-gradient(ellipse at 50% 0%, rgba(139,92,246,0.12) 0%, transparent 70%); }
.stat-card--purple:hover   { box-shadow: 0 12px 40px rgba(139,92,246,0.18); }

.stat-card--green { border-color: rgba(34,197,94,0.35); }
.stat-card--green::before  { background: radial-gradient(ellipse at 50% 0%, rgba(34,197,94,0.12) 0%, transparent 70%); }
.stat-card--green:hover    { box-shadow: 0 12px 40px rgba(34,197,94,0.18); }

.stat-card-icon {
  font-size: 1.5rem;
  margin-bottom: 10px;
  display: block;
}

.stat-card-num {
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 900;
  line-height: 1;
  margin-bottom: 6px;
  letter-spacing: -0.03em;
  font-family: 'Nunito', 'Arial Nova', 'Arial', sans-serif;
}

.stat-card--blue   .stat-card-num { background: linear-gradient(135deg,#3b82f6,#60a5fa); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; }
.stat-card--cyan   .stat-card-num { background: linear-gradient(135deg,#06b6d4,#22d3ee); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; }
.stat-card--purple .stat-card-num { background: linear-gradient(135deg,#8b5cf6,#a78bfa); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; }
.stat-card--green  .stat-card-num { background: linear-gradient(135deg,#22c55e,#4ade80); -webkit-background-clip:text; -webkit-text-fill-color:transparent; background-clip:text; }

.stat-card-num--text {
  background: linear-gradient(135deg,#22c55e,#4ade80);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-card-label {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
}

.stat-card-sub {
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.03em;
}

/* ─── WHY SECTION ─────────────────────────────────────────────── */
.why-section {
  margin-top: 64px;
  padding: 0 4px;
}

.why-section-header {
  text-align: center;
  margin-bottom: 32px;
}

.why-badge {
  display: inline-block;
  background: var(--glow);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 6px 18px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent2);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.why-subtitle {
  color: var(--muted);
  font-size: 0.9rem;
}

.why-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

@media (min-width: 600px) {
  .why-grid { grid-template-columns: repeat(3, 1fr); }
}

.why-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.2s, border-color 0.2s;
}
.why-card:hover { transform: translateY(-3px); border-color: var(--border); }

.why-card-icon {
  width: 42px; height: 42px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.why-icon--blue   { background: var(--border); }
.why-icon--cyan   { background: rgba(6,182,212,0.15); }
.why-icon--purple { background: rgba(139,92,246,0.15); }
.why-icon--amber  { background: rgba(251,191,36,0.15); }
.why-icon--green  { background: rgba(34,197,94,0.15); }
.why-icon--rose   { background: rgba(244,63,94,0.15); }

.why-card-body h3 {
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 4px;
  font-family: 'Nunito', 'Arial Nova', sans-serif;
  line-height: 1.2;
}

.why-card-body p {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ─── POPULAR MATERIALS ──────────────────────────────────────── */
.popular-section {
  margin-top: 56px;
}

.popular-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.popular-see-all {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--accent2);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 6px 14px;
  cursor: pointer;
  transition: background 0.18s, border-color 0.18s;
}
.popular-see-all:hover { background: rgba(6,182,212,0.08); border-color: rgba(6,182,212,0.4); }

.popular-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 480px) {
  .popular-cards { grid-template-columns: repeat(3, 1fr); }
}

.popular-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.popular-card:hover { transform: translateY(-3px); box-shadow: 0 8px 30px var(--glow); }

.popular-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.popular-card-course {
  font-size: 0.68rem;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 0.05em;
}

.popular-card-badge {
  font-size: 0.65rem;
  font-weight: 700;
  border-radius: 6px;
  padding: 2px 8px;
}
.popular-badge--hot { background: rgba(251,113,30,0.15); color: #fb7120; }
.popular-badge--new { background: rgba(139,92,246,0.15); color: #a78bfa; }

.popular-card-title {
  font-size: 0.95rem;
  font-weight: 800;
  font-family: 'Nunito', 'Arial Nova', sans-serif;
  color: var(--text);
}

.popular-card-meta {
  font-size: 0.72rem;
  color: var(--muted);
}

.popular-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 6px;
}

.popular-card-views { font-size: 0.7rem; color: var(--muted); }

.popular-card-btn {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border: none;
  border-radius: 8px;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 5px 12px;
  cursor: pointer;
  transition: opacity 0.18s;
}
.popular-card-btn:hover { opacity: 0.85; }

/* ─── Neon tema xüsusi effektlər ───────────────────────────── */
body[data-theme="neon"] .course-card:hover,
body[data-theme="neon"] .subject-card:hover {
  box-shadow: 0 0 18px rgba(0,255,136,0.25), 0 0 40px rgba(0,255,136,0.08);
}

body[data-theme="neon"] .logo {
  text-shadow: 0 0 12px rgba(0,255,136,0.5);
}

body[data-theme="neon"] .hero-badge {
  box-shadow: 0 0 10px rgba(0,255,136,0.2);
}

/* ─── Rainbow tema — gradient aksent başlıqlar ─────────────── */
body[data-theme="rainbow"] h1 span,
body[data-theme="rainbow"] h2 span {
  background: linear-gradient(90deg, #c026d3, #f59e0b, #06b6d4, #c026d3);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: rainbowShift 4s linear infinite;
}

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

/* ─── Sakura tema — soft şəffaf kart kənarları ─────────────── */
body[data-theme="sakura"] .course-card,
body[data-theme="sakura"] .subject-card {
  border-color: rgba(244,114,182,0.2);
}

body[data-theme="sakura"] .course-card:hover {
  box-shadow: 0 8px 32px rgba(244,114,182,0.15);
}