:root {
  /* ── Brand ───────────────────────────────────────────── */
  --primary:       #f97316;
  --primary-dark:  #ea580c;
  --primary-light: #fff7ed;
  --primary-glow:  rgba(249, 115, 22, 0.14);

  /* ── Accent (urgency / CTA energy) ──────────────────── */
  --accent:        #0ea5e9;
  --accent-dark:   #0284c7;
  --accent-light:  #f0f9ff;

  /* ── Semantic ────────────────────────────────────────── */
  --success:       #16a34a;
  --success-light: #dcfce7;
  --error:         #dc2626;
  --error-light:   #fee2e2;
  --warning:       #d97706;
  --warning-light: #fef3c7;
  --info:          #3b82f6;
  --info-light:    #dbeafe;

  /* ── App shell layout ────────────────────────────────── */
  --sidebar-width:     260px;
  --sidebar-collapsed: 72px;
  --topbar-height:     64px;
  --bottomnav-height:  60px;

  /* ── Surface ─────────────────────────────────────────── */
  --bg:            #fafafa;
  --bg-alt:        #f4f4f5;
  --bg-warm:       #fffbeb;
  --bg-dark:       #09090b;
  --surface:       #ffffff;

  /* ── Text ────────────────────────────────────────────── */
  --text:          #09090b;
  --text-secondary:#52525b;
  --text-light:    #71717a;

  /* ── Border ──────────────────────────────────────────── */
  --border:        #e5e7eb;
  --border-light:  #f3f4f6;

  /* ── Subject colors (canonical — used everywhere) ─────
     Türkçe:      red-500     #ef4444
     Matematik:   blue-500    #3b82f6
     Geometri:    violet-500  #8b5cf6
     Tarih:       amber-500   #f59e0b
     Coğrafya:    emerald-500 #10b981
     Vatandaşlık: indigo-500  #6366f1
     Güncel:      pink-500    #ec4899
     ─────────────────────────────────────────────────── */
  --turkce:        #ef4444;
  --turkce-light:  #fef2f2;
  --turkce-dark:   #dc2626;
  --matematik:     #3b82f6;
  --matematik-light:#eff6ff;
  --matematik-dark: #2563eb;
  --geometri:      #8b5cf6;
  --geometri-light:#f5f3ff;
  --geometri-dark: #7c3aed;
  --tarih:         #f59e0b;
  --tarih-light:   #fffbeb;
  --tarih-dark:    #d97706;
  --cografya:      #10b981;
  --cografya-light:#ecfdf5;
  --cografya-dark: #059669;
  --vatandaslik:   #6366f1;
  --vatandaslik-light:#eef2ff;
  --vatandaslik-dark: #4338ca;
  --guncel:        #ec4899;
  --guncel-light:  #fdf2f8;
  --guncel-dark:   #db2777;

  /* ── Spacing ─────────────────────────────────────────── */
  --radius:    12px;
  --radius-sm:  8px;
  --radius-lg: 16px;

  /* ── Shadows ─────────────────────────────────────────── */
  --shadow-sm: 0 1px 2px rgba(0,0,0,.04);
  --shadow:    0 2px 8px -2px rgba(0,0,0,.08), 0 1px 2px -1px rgba(0,0,0,.04);
  --shadow-lg: 0 12px 24px -8px rgba(0,0,0,.1);
  --shadow-xl: 0 20px 40px -12px rgba(0,0,0,.15);
  --focus-ring: 0 0 0 2px rgba(249, 115, 22, 0.28);

  /* ── Motion ──────────────────────────────────────────── */
  --transition:      .15s ease;
  --transition-slow: .3s cubic-bezier(.4,0,.2,1);

  /* ── Z-index scale ───────────────────────────────────── */
  --z-back-to-top: 90;
  --z-nav:        100;
  --z-modal:     1000;
  --z-skip-link: 9999;
}

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

.skip-link {
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  z-index: 9999;
  transition: top .3s;
}
.skip-link:focus {
  top: 10px;
  outline: 2px solid var(--primary-dark);
  outline-offset: 2px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ══════════════════════════════════════════════════════════════════════════════
   NAV
   ══════════════════════════════════════════════════════════════════════════════ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255,255,255,.78);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid rgba(228,228,231,.55);
  transition: background var(--transition), box-shadow var(--transition);
}

.nav.scrolled {
  background: rgba(255,255,255,.94);
  box-shadow: 0 1px 0 rgba(228,228,231,.9), 0 8px 24px -16px rgba(9,9,11,.12);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.02em;
  display: inline-flex;
  align-items: center;
  gap: 2px;
}

.nav-logo span { 
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-links a {
  font-size: .8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 8px 12px;
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  border-radius: 100px;
  transition: all var(--transition);
}

.nav-links a:hover {
  color: var(--text);
  background: var(--bg-alt);
}

.nav-links a:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  color: var(--text);
}

.nav-active {
  color: var(--primary) !important;
  background: var(--primary-light) !important;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px !important;
  min-height: 40px;
  margin-left: 6px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark)) !important;
  color: #fff !important;
  border-radius: 100px;
  font-weight: 600;
  font-size: .8125rem;
  transition: all var(--transition);
  border: none;
  cursor: pointer;
  font-family: inherit;
  text-decoration: none;
  box-shadow: 0 2px 10px var(--primary-glow);
}

.nav-cta:hover {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-dark)) !important;
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(249,115,22,.32);
}

.nav-cta:focus-visible {
  outline: 2px solid var(--primary-dark);
  outline-offset: 2px;
}

.nav-auth-item {
  display: inline-flex;
  align-items: center;
  gap: 2px;
}

.nav-login-link {
  font-weight: 600 !important;
  color: var(--text) !important;
}

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 10px;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.hamburger:hover { background: var(--bg-alt); }

.hamburger:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  background: var(--bg-alt);
}

.hamburger span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all var(--transition);
}

.hamburger.open span:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: translateX(-10px); }
.hamburger.open span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }

/* ══════════════════════════════════════════════════════════════════════════════
   HERO
   ══════════════════════════════════════════════════════════════════════════════ */
.hero {
  padding: 120px 0 80px;
  background: var(--bg);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 800px;
  height: 400px;
  background: radial-gradient(ellipse 100% 100% at 50% 0%, var(--primary-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  display: none;
}

.hero-center {
  max-width: 680px;
  margin: 0 auto;
  text-align: center;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 560px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--primary-light);
  border: 1px solid rgba(249,115,22,.2);
  color: var(--primary);
  border-radius: 100px;
  font-size: .75rem;
  font-weight: 600;
  margin-bottom: 20px;
  text-transform: uppercase;
  letter-spacing: .03em;
}

.hero h1 {
  font-size: 3.25rem;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -.03em;
  color: var(--text);
  margin-bottom: 20px;
}

.hero h1 em {
  font-style: normal;
  color: var(--primary);
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius);
  font-size: .95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  color: #fff;
}

.btn-primary:focus {
  outline: none;
  box-shadow: var(--focus-ring), 0 4px 14px var(--primary-glow);
}

.btn-primary:focus-visible {
  outline: 2px solid var(--primary-dark);
  outline-offset: 2px;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: .95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

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

.btn-secondary:focus {
  outline: none;
  box-shadow: var(--focus-ring);
}

.btn-secondary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

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

.hero-stat-num {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.02em;
}

.hero-stat-label {
  font-size: .8rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ══════════════════════════════════════════════════════════════════════════════
   IPHONE MOCKUP WITH IMAGE
   ══════════════════════════════════════════════════════════════════════════════ */
.phone-mockup {
  position: relative;
  width: 320px;
  filter: drop-shadow(0 24px 48px rgba(0,0,0,.15));
}

@keyframes phone-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.phone-frame {
  width: 100%;
  height: auto;
  display: block;
}

.phone-screen {
  position: absolute;
  top: 2%;
  left: 8.2%;
  width: 83.6%;
  height: 96%;
  border-radius: 48px;
  overflow: hidden;
  background: linear-gradient(160deg, #0f172a 0%, #1c1917 50%, #292524 100%);
  display: flex;
  flex-direction: column;
}

.screen-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 28px 0;
  height: 52px;
}

.status-time {
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}

.status-icons {
  display: flex;
  align-items: center;
  gap: 6px;
}

.screen-app {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 24px;
}

.app-badge {
  font-size: 11px;
  font-weight: 700;
  color: rgba(255,255,255,.7);
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.app-date {
  font-size: 26px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 24px;
}

.app-ring {
  position: relative;
  width: 150px;
  height: 150px;
  margin-bottom: 24px;
}

.app-ring svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 0 20px rgba(249,115,22,.4));
}

.ring-text {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.ring-days {
  font-size: 48px;
  font-weight: 700;
  color: #fff;
  line-height: 1;
}

.ring-label {
  font-size: 13px;
  font-weight: 500;
  color: rgba(255,255,255,.5);
  margin-top: 4px;
}

.app-timers {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 28px;
}

.timer-box {
  background: rgba(255,255,255,.1);
  border-radius: 14px;
  padding: 14px 18px;
  text-align: center;
  min-width: 64px;
}

.timer-val {
  display: block;
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  font-variant-numeric: tabular-nums;
}

.timer-lbl {
  display: block;
  font-size: 11px;
  font-weight: 500;
  color: rgba(255,255,255,.4);
  margin-top: 2px;
}

.timer-colon {
  font-size: 22px;
  font-weight: 600;
  color: rgba(255,255,255,.25);
}

.app-cta {
  width: 100%;
  padding: 18px 24px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: 16px;
  font-size: 17px;
  font-weight: 600;
  color: #fff;
  text-align: center;
  box-shadow: 0 10px 30px rgba(249,115,22,.35);
  margin-top: auto;
}

.screen-home-bar {
  width: 140px;
  height: 5px;
  background: rgba(255,255,255,.25);
  border-radius: 100px;
  margin: 12px auto 8px;
}

/* ══════════════════════════════════════════════════════════════════════════════
   SECTIONS
   ══════════════════════════════════════════════════════════════════════════════ */
section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 64px;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--text);
  margin-bottom: 12px;
}

.section-header p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ══════════════════════════════════════════════════════════════════════════════
   FEATURES
   ══════════════════════════════════════════════════════════════════════════════ */
.features {
  background: var(--bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  display: none;
}

.feature-card:hover {
  border-color: var(--border);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.feature-card:hover::before { opacity: 0; }

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-light);
  border-radius: var(--radius-sm);
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}

.feature-card p {
  font-size: .9rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ══════════════════════════════════════════════════════════════════════════════
   CALENDAR TABLE
   ══════════════════════════════════════════════════════════════════════════════ */
#takvim {
  background: var(--bg-alt);
}

.calendar-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: var(--bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.calendar-table th,
.calendar-table td {
  padding: 20px 24px;
  text-align: left;
}

.calendar-table thead {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

.calendar-table th {
  font-size: .8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: #fff;
}

.calendar-table tbody tr {
  border-bottom: 1px solid var(--border-light);
  transition: background var(--transition);
}

.calendar-table tbody tr:last-child { border-bottom: none; }
.calendar-table tbody tr:hover { background: var(--bg-alt); }

.calendar-table td {
  font-size: .95rem;
  color: var(--text);
}

.calendar-table td strong {
  color: var(--primary);
  font-weight: 700;
}

.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 100px;
  font-size: .75rem;
  font-weight: 700;
  margin-right: 10px;
}

.badge-lisans { background: var(--primary-light); color: var(--primary-dark); }
.badge-onlisans { background: var(--success-light); color: var(--success); }
.badge-ortaogretim { background: var(--accent-light); color: var(--accent-dark); }
.badge-dhbt { background: #fae8ff; color: #a855f7; }

/* ══════════════════════════════════════════════════════════════════════════════
   STATS
   ══════════════════════════════════════════════════════════════════════════════ */
.stats {
  background: linear-gradient(135deg, var(--bg-dark), #1e293b);
  padding: 80px 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.stat-item {
  text-align: center;
  padding: 32px;
  background: rgba(255,255,255,.03);
  border: 1px solid rgba(255,255,255,.06);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(10px);
  transition: all var(--transition);
}

.stat-item:hover {
  background: rgba(255,255,255,.06);
  transform: translateY(-4px);
}

.stat-item h3 {
  font-size: 2.5rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 6px;
  letter-spacing: -.02em;
}

.stat-item p {
  font-size: .95rem;
  color: rgba(255,255,255,.6);
  font-weight: 500;
}

/* ══════════════════════════════════════════════════════════════════════════════
   TOPICS
   ══════════════════════════════════════════════════════════════════════════════ */
#konular {
  background: var(--bg);
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.topic-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition);
}

.topic-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.topic-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.topic-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.topic-list li {
  font-size: .9rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.topic-list li::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--primary);
  border-radius: 50%;
  flex-shrink: 0;
}

/* ══════════════════════════════════════════════════════════════════════════════
   CTA SECTION
   ══════════════════════════════════════════════════════════════════════════════ */
.cta-section {
  background: var(--bg-dark);
  text-align: center;
  padding: 80px 0;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  display: none;
}

.cta-section > .container {
  position: relative;
  z-index: 1;
}

.cta-section h2 {
  font-size: 2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
  letter-spacing: -.02em;
}

.cta-section p {
  font-size: 1.05rem;
  color: rgba(255,255,255,.7);
  max-width: 550px;
  margin: 0 auto 28px;
  line-height: 1.65;
}

.cta-section .btn-primary {
  background: #fff;
  color: var(--text);
}

.cta-section .btn-primary:hover {
  background: var(--bg-alt);
  color: var(--text);
}

/* ══════════════════════════════════════════════════════════════════════════════
   FAQ
   ══════════════════════════════════════════════════════════════════════════════ */
#sss {
  background: var(--bg-alt);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  transition: all var(--transition);
}

.faq-item:hover { border-color: var(--primary); }
.faq-item.open { border-color: var(--primary); box-shadow: var(--shadow); }

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  text-align: left;
  font-family: inherit;
  transition: color var(--transition);
}

.faq-question:hover { color: var(--primary); }

.faq-question:focus {
  outline: none;
  color: var(--primary);
}

.faq-question:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
  border-radius: var(--radius-sm);
}

.faq-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-alt);
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: 400;
  color: var(--text-secondary);
  transition: all var(--transition);
  flex-shrink: 0;
  margin-left: 16px;
}

.faq-item.open .faq-icon {
  background: var(--primary);
  color: #fff;
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .4s ease, padding .4s ease;
}

.faq-item.open .faq-answer {
  max-height: 400px;
  padding: 0 24px 24px;
}

.faq-answer p {
  color: var(--text-secondary);
  font-size: .95rem;
  line-height: 1.8;
}

/* ══════════════════════════════════════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════════════════════════════════════ */
.footer {
  background: var(--bg-dark);
  color: rgba(255,255,255,.6);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.footer-brand h3 span { 
  color: var(--primary-light);
}

.footer-brand p {
  font-size: .9rem;
  line-height: 1.7;
}

.footer-col h4 {
  color: #fff;
  font-size: .8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  margin-bottom: 20px;
}

.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 12px; }

.footer-col a {
  color: rgba(255,255,255,.6);
  font-size: .9rem;
  transition: color var(--transition);
}

.footer-col a:hover { color: #fff; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  padding-top: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: .85rem;
}

.footer-bottom-links {
  display: flex;
  gap: 24px;
}

.footer-bottom-links a { color: rgba(255,255,255,.5); }
.footer-bottom-links a:hover { color: #fff; }

/* ══════════════════════════════════════════════════════════════════════════════
   LEGAL PAGES
   ══════════════════════════════════════════════════════════════════════════════ */
.legal-page {
  padding: 140px 0 80px;
  min-height: 100vh;
}

.legal-page h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -.02em;
  margin-bottom: 8px;
}

.legal-page .last-updated {
  color: var(--text-secondary);
  font-size: .9rem;
  margin-bottom: 48px;
}

.legal-page h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 16px;
}

.legal-page p,
.legal-page li {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.legal-page ul {
  padding-left: 24px;
  margin-bottom: 24px;
}

/* ══════════════════════════════════════════════════════════════════════════════
   BLOG
   ══════════════════════════════════════════════════════════════════════════════ */
.blog-page {
  padding: 140px 0 80px;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.blog-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-slow);
}

.blog-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
  border-color: transparent;
}

.blog-card-img {
  height: 200px;
  background: linear-gradient(135deg, var(--primary-light), #ddd6fe);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
}

.blog-card-body { padding: 28px; }

.blog-card-body .tag {
  display: inline-block;
  padding: 4px 12px;
  background: var(--primary-light);
  color: var(--primary-dark);
  border-radius: 100px;
  font-size: .75rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.blog-card-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
  color: var(--text);
}

.blog-card-body p {
  color: var(--text-secondary);
  font-size: .9rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.blog-card-body .read-more {
  font-size: .9rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.blog-card-body .read-more:hover { gap: 10px; }

/* ══════════════════════════════════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════════════════════════════════ */
@media (max-width: 1024px) {
  .hero h1 { font-size: 2.75rem; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 40px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { 
    display: none;
    visibility: hidden;
  }
  .hamburger { display: flex; }

  .nav-links.open {
    display: flex;
    visibility: visible;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(255,255,255,.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    padding: 12px 16px 20px;
    gap: 4px;
    box-shadow: 0 24px 48px -20px rgba(9,9,11,.18);
    animation: menuSlideDown .22s cubic-bezier(.4,0,.2,1);
  }

  @keyframes menuSlideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .nav-links.open a { 
    padding: 14px 16px;
    min-height: 48px;
    width: 100%;
    border-radius: var(--radius);
    font-size: .9375rem;
    font-weight: 600;
    color: var(--text);
  }
  
  .nav-links.open a:active {
    background: var(--bg-alt);
  }

  .nav-links.open .nav-cta {
    margin-top: 2px;
    margin-left: 0;
    justify-content: center;
    width: 100%;
    min-height: 48px;
    border-radius: var(--radius);
  }
  .nav-links.open .nav-auth-item {
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    margin-top: 10px;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
  }
  .nav-links.open .nav-login-link {
    justify-content: center;
    border: 1.5px solid var(--border);
    min-height: 48px;
  }

  .hero { padding: 100px 0 60px; }
  .hero-center { max-width: 100%; }
  .hero h1 { font-size: 2rem; }
  .hero-buttons { justify-content: center; }
  .hero-stats { gap: 20px; flex-wrap: wrap; }
  .hero-stat-num { font-size: 1.25rem; }

  section { padding: 72px 0; }
  .section-header { margin-bottom: 48px; }
  .section-header h2 { font-size: 1.75rem; }
  .features-grid { grid-template-columns: 1fr; }
  .topics-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 16px; }
  .stat-item { padding: 24px 16px; }
  .stat-item h3 { font-size: 2rem; }

  .calendar-table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; font-size: .85rem; }
  .calendar-table th, .calendar-table td { padding: 14px 16px; white-space: nowrap; }

  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
  .footer-col a { display: inline-block; padding: 4px 0; }
  .footer-bottom-links a { display: inline-block; padding: 8px 4px; }

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

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero-badge { max-width: 100%; flex-wrap: wrap; justify-content: center; row-gap: 2px; }
  .hero h1 { font-size: 1.625rem; }
  .hero-buttons { flex-direction: column; align-items: stretch; }
  .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
  .hero-stats { gap: 16px; }
  .hero-stat { min-width: 70px; }
  .hero-stat-num { font-size: 1.125rem; }
  .topic-list { grid-template-columns: 1fr; }
  section { padding: 64px 0; }
  .cta-section h2 { font-size: 1.5rem; }
}

/* ══════════════════════════════════════════════════════════════════════════════
   PREMIUM SHOWCASE
   ══════════════════════════════════════════════════════════════════════════════ */
.premium-showcase {
  padding: 100px 0;
  background: var(--bg);
  position: relative;
  overflow: hidden;
}

.premium-showcase::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.premium-showcase-header {
  text-align: center;
  max-width: 560px;
  margin: 0 auto 72px;
}

.premium-showcase-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border-radius: 100px;
  font-size: .75rem;
  font-weight: 600;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: .03em;
}

.premium-showcase-header h2 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--text);
  margin-bottom: 12px;
}

.premium-showcase-header p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.premium-showcase-items {
  display: flex;
  flex-direction: column;
  gap: 80px;
}

.premium-showcase-item {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.premium-showcase-item:nth-child(even) {
  direction: rtl;
}

.premium-showcase-item:nth-child(even) > * {
  direction: ltr;
}

.premium-showcase-text {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.premium-showcase-text .showcase-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  flex-shrink: 0;
}

.premium-showcase-text .showcase-icon-learn {
  background: #ede9fe;
  color: #7c3aed;
}

.premium-showcase-text .showcase-icon-questions {
  background: #dbeafe;
  color: #2563eb;
}

.premium-showcase-text .showcase-icon-exams {
  background: var(--success-light);
  color: var(--success);
}

.premium-showcase-text h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.01em;
}

.premium-showcase-text p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.premium-showcase-text ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.premium-showcase-text ul li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: .9rem;
  color: var(--text);
}

.premium-showcase-text ul li svg {
  flex-shrink: 0;
}

.premium-showcase-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  min-height: 280px;
}

.premium-showcase-visual svg {
  width: 100%;
  max-width: 280px;
  height: auto;
}

.premium-showcase-cta {
  text-align: center;
  margin-top: 72px;
  padding-top: 48px;
  border-top: 1px solid var(--border);
}

.premium-showcase-cta p {
  font-size: .9rem;
  color: var(--text-secondary);
  margin-top: 12px;
}

@media (max-width: 768px) {
  .premium-showcase { padding: 72px 0; }
  .premium-showcase-items { gap: 56px; }
  .premium-showcase-item {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .premium-showcase-item:nth-child(even) {
    direction: ltr;
  }
  .premium-showcase-visual {
    min-height: 200px;
    padding: 24px;
  }
  .premium-showcase-header { margin-bottom: 48px; }
  .premium-showcase-text h3 { font-size: 1.3rem; }
}

@media (max-width: 480px) {
  .premium-showcase { padding: 56px 0; }
  .premium-showcase-header h2 { font-size: 1.5rem; }
  .premium-showcase-cta { margin-top: 48px; padding-top: 32px; }
}

/* ══════════════════════════════════════════════════════════════════════════════
   ANIMATIONS
   ══════════════════════════════════════════════════════════════════════════════ */
.fade-in {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .5s ease, transform .5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ══════════════════════════════════════════════════════════════════════════════
   BACK TO TOP
   ══════════════════════════════════════════════════════════════════════════════ */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 90;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  box-shadow: 0 8px 24px var(--primary-glow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(249,115,22,.4);
}

.back-to-top:focus {
  outline: none;
  box-shadow: var(--focus-ring), 0 8px 24px var(--primary-glow);
}

.back-to-top:focus-visible {
  outline: 2px solid #fff;
  outline-offset: 2px;
}

.back-to-top svg { width: 20px; height: 20px; }

/* ══════════════════════════════════════════════════════════════════════════════
   NAV USER
   ══════════════════════════════════════════════════════════════════════════════ */
.nav-user-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 14px 6px 6px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: .875rem;
  font-weight: 500;
  color: var(--text) !important;
  transition: all var(--transition);
}

.nav-user-link:hover {
  background: var(--bg);
  border-color: var(--primary);
}

.nav-user-avatar {
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  border-radius: 50%;
  font-size: .8rem;
  font-weight: 700;
}

.nav-user-avatar-img {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
}

.nav-user-name {
  max-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

@media (max-width: 768px) {
  .back-to-top { bottom: 16px; right: 16px; width: 44px; height: 44px; }
}

.breadcrumb {
  padding: 14px 0;
  margin-bottom: 4px;
}
.breadcrumb ol {
  list-style: none;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 2px 4px;
  margin: 0;
  padding: 0;
}
.breadcrumb li {
  display: inline-flex;
  align-items: center;
  font-size: .85rem;
  line-height: 1;
  color: var(--text-light);
  max-width: 100%;
}
.breadcrumb li:not(:last-child)::after {
  content: '';
  width: 6px;
  height: 6px;
  margin: 0 2px;
  border-right: 1.5px solid var(--border);
  border-top: 1.5px solid var(--border);
  transform: rotate(45deg);
  flex-shrink: 0;
}
.breadcrumb a {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 8px;
  color: var(--text-secondary);
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--transition), color var(--transition);
}
.breadcrumb a:hover {
  color: var(--primary);
  background: var(--primary-light);
}
.breadcrumb a:focus { outline: none; }
.breadcrumb a:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
  border-radius: 8px;
}
.breadcrumb li[aria-current="page"] {
  padding: 6px 10px;
  color: var(--text);
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 60vw;
}

@media (max-width: 640px) {
  .breadcrumb {
    padding: 10px 0;
  }
  .breadcrumb ol {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: 2px;
  }
  .breadcrumb ol::-webkit-scrollbar { display: none; }
  .breadcrumb li { flex-shrink: 0; font-size: .8rem; }
  .breadcrumb a { padding: 7px 9px; }
  .breadcrumb li[aria-current="page"] {
    max-width: none;
    overflow: visible;
    text-overflow: clip;
  }
}

.pulse {
  animation: pulse-scale 0.15s ease-out;
}

@keyframes pulse-scale {
  0% { transform: scale(1); }
  50% { transform: scale(1.08); }
  100% { transform: scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  .phone-mockup {
    animation: none;
  }
  .fade-in {
    transition: none;
    opacity: 1;
    transform: none;
  }
  .pulse {
    animation: none;
  }
}

/* ══════════════════════════════════════════════════════════════════════════════
   NAV PREMIUM MODAL
   ══════════════════════════════════════════════════════════════════════════════ */
.nav-premium-overlay {
  position: fixed;
  inset: 0;
  z-index: 1100;
  background: rgba(9,9,11,.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  opacity: 0;
  visibility: hidden;
  transition: opacity .2s ease, visibility .2s ease;
}

.nav-premium-overlay.open {
  opacity: 1;
  visibility: visible;
}

.nav-premium-modal {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 560px;
  box-shadow: 0 24px 64px -12px rgba(0,0,0,.22);
  transform: translateY(12px) scale(.98);
  transition: transform .2s ease;
  overflow: hidden;
}

.nav-premium-overlay.open .nav-premium-modal {
  transform: translateY(0) scale(1);
}

.nav-premium-modal-head {
  padding: 24px 24px 0;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.nav-premium-modal-head-text h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 4px;
  letter-spacing: -.01em;
}

.nav-premium-modal-head-text p {
  font-size: .85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.nav-premium-modal-close {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-alt);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: all var(--transition);
  line-height: 1;
}

.nav-premium-modal-close:hover {
  background: var(--border);
  color: var(--text);
}

.nav-premium-plans {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 24px 24px;
}

.nav-premium-plan {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 18px;
  background: var(--bg-alt);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  text-align: left;
  width: 100%;
  font-family: inherit;
  position: relative;
}

.nav-premium-plan:hover {
  border-color: var(--primary);
  background: var(--primary-light);
}

.nav-premium-plan.featured {
  border-color: var(--primary);
  background: var(--primary-light);
}

.nav-premium-plan-badge {
  position: absolute;
  top: -10px;
  left: 18px;
  background: var(--primary);
  color: #fff;
  font-size: .68rem;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 100px;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.nav-premium-plan-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-premium-plan-name {
  font-size: .9rem;
  font-weight: 600;
  color: var(--text);
}

.nav-premium-plan-desc {
  font-size: .78rem;
  color: var(--text-secondary);
}

.nav-premium-plan-price {
  flex-shrink: 0;
  text-align: right;
}

.nav-premium-plan-price strong {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
}

.nav-premium-plan-price span {
  font-size: .72rem;
  color: var(--text-secondary);
}

.nav-premium-plan-arrow {
  flex-shrink: 0;
  color: var(--primary);
  opacity: .6;
  transition: opacity var(--transition), transform var(--transition);
}

.nav-premium-plan:hover .nav-premium-plan-arrow {
  opacity: 1;
  transform: translateX(2px);
}

.nav-premium-modal-footer {
  padding: 0 24px 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: .78rem;
  color: var(--text-secondary);
}

.nav-premium-modal-footer a {
  color: var(--primary);
  font-weight: 500;
}

.nav-premium-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 0;
  font-size: .85rem;
  color: var(--text-secondary);
}

@media (max-width: 480px) {
  .nav-premium-modal-head { padding: 20px 16px 0; }
  .nav-premium-plans { padding: 16px 16px 20px; }
  .nav-premium-modal-footer { padding: 0 16px 18px; }
  .nav-premium-plan { padding: 14px 14px; }
}

/* Minimal legal footer for auth/payment/utility pages */
.legal-footer {
  padding: 20px 16px;
  text-align: center;
  font-size: .8rem;
  color: var(--text-light, #71717a);
  border-top: 1px solid var(--border);
  background: var(--bg);
}
.legal-footer a {
  color: var(--text-secondary);
  text-decoration: none;
  margin: 0 8px;
}
.legal-footer a:hover { color: var(--primary); }