:root {
  --bg:      #060610;
  --bg2:     #0c0c1a;
  --bg3:     #111122;
  --bg4:     #16162e;
  --bg5:     #1c1c38;
  --surface: rgba(255,255,255,0.03);
  --surface2: rgba(255,255,255,0.05);
  --surface3: rgba(255,255,255,0.08);
  --border:  rgba(255,255,255,0.06);
  --border2: rgba(255,255,255,0.10);
  --t1:      #ffffff;
  --t2:      rgba(255,255,255,0.65);
  --t3:      rgba(255,255,255,0.40);
  --t4:      rgba(255,255,255,0.22);
  --blue:    #4A90E2;
  --blue-glow: rgba(74,144,226,0.25);
  --green:   #00E676;
  --green-glow: rgba(0,230,118,0.20);
  --accent:  #FFA726;
  --accent-glow: rgba(255,167,38,0.20);
  --purple:  #B388FF;
  --purple-glow: rgba(179,136,255,0.18);
  --streak:  #FF6B35;
  --error:   #EF5350;
  --ease:    cubic-bezier(.22,1,.36,1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; }
body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--t1);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

/* Noise */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  opacity: .5;
}

/* LCP: GSAP yüklenmeden önce splash içeriği görünür olsun */
#splash-header, .split-hero, .role-card { opacity: 1; transform: none; }

/* Splash */
.splash-screen {
  position: fixed; inset: 0; z-index: 100;
  background: var(--bg);
  display: flex; align-items: flex-start; justify-content: center;
  overflow-y: auto;
  transition: opacity 0.6s ease, visibility 0.6s ease;
}
.splash-screen > .w-full { margin-top: auto; margin-bottom: auto; }
.splash-screen.hidden { opacity: 0; visibility: hidden; pointer-events: none; }
.tool-chip {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 18px; border-radius: 999px;
  font-size: 14px; font-weight: 700; color: #fff; text-decoration: none;
  background: rgba(74,144,226,0.10);
  border: 1px solid rgba(74,144,226,0.25);
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}
.tool-chip:hover {
  background: rgba(74,144,226,0.20);
  border-color: rgba(74,144,226,0.45);
  transform: translateY(-2px);
}
@media (max-width: 640px) {
  .tool-chip { padding: 9px 14px; font-size: 12.5px; gap: 6px; }
}

.splash-mesh {
  position: absolute; border-radius: 50%; filter: blur(120px); pointer-events: none;
  animation: meshFloat 8s ease-in-out infinite alternate;
}
.splash-mesh-1 { width: 600px; height: 600px; background: rgba(74,144,226,0.08); top: -15%; left: -10%; }
.splash-mesh-2 { width: 500px; height: 500px; background: rgba(0,230,118,0.06); bottom: -10%; right: -5%; animation-delay: -4s; }
.splash-mesh-3 { width: 300px; height: 300px; background: rgba(179,136,255,0.05); top: 40%; left: 50%; animation-delay: -2s; }
@keyframes meshFloat {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(30px, -20px) scale(1.1); }
}

.role-card {
  cursor: pointer; perspective: 900px;
  transition: transform 0.5s var(--ease);
}
.role-card:hover { transform: translateY(-10px) scale(1.02); }
.role-card-inner {
  border-radius: 24px; padding: 3rem 2.5rem;
  background: var(--surface2); border: 1px solid var(--border);
  backdrop-filter: blur(20px);
  transition: all 0.5s var(--ease);
  position: relative; overflow: hidden;
}
.role-card:hover .role-card-inner {
  border-color: var(--border2);
  box-shadow: 0 25px 60px -12px rgba(0,0,0,0.5);
}
.role-card-inner::before {
  content: ''; position: absolute; inset: 0; border-radius: 24px;
  opacity: 0; transition: opacity 0.5s ease;
}
.role-card:hover .role-card-inner::before { opacity: 1; }
.role-card.student .role-card-inner::before { background: linear-gradient(135deg, rgba(74,144,226,0.06), rgba(74,144,226,0.12)); }
.role-card.student:hover .role-card-inner { border-color: rgba(74,144,226,0.25); box-shadow: 0 25px 60px -12px rgba(74,144,226,0.15); }
.role-card.teacher .role-card-inner::before { background: linear-gradient(135deg, rgba(0,230,118,0.06), rgba(0,230,118,0.12)); }
.role-card.teacher:hover .role-card-inner { border-color: rgba(0,230,118,0.25); box-shadow: 0 25px 60px -12px rgba(0,230,118,0.15); }

/* Nav */
.main-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  background: rgba(6,6,16,0.75);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid transparent;
  transform: translateY(-100%);
  transition: transform 0.5s var(--ease), opacity 0.5s ease, border-color 0.3s;
  opacity: 0;
}
.main-nav.visible { transform: translateY(0); opacity: 1; }
.main-nav.scrolled { border-color: var(--border); }

/* Phone Mockup */
.phone-mockup { position: relative; width: 280px; margin: 0 auto; }
.phone-frame {
  background: #1a1a2e; border-radius: 40px; padding: 12px;
  box-shadow: 0 30px 80px -15px rgba(0,0,0,0.6), 0 0 0 1px rgba(255,255,255,0.08) inset, 0 0 60px -10px var(--phone-glow, rgba(74,144,226,0.15));
}
.phone-screen { border-radius: 30px; overflow: hidden; aspect-ratio: 9 / 19.5; background: #000; }
.phone-screen img { width: 100%; height: 100%; object-fit: cover; display: block; }
.phone-notch { position: absolute; top: 12px; left: 50%; transform: translateX(-50%); width: 120px; height: 28px; background: #1a1a2e; border-radius: 0 0 18px 18px; z-index: 2; }
.teacher-page .phone-frame { --phone-glow: rgba(0,230,118,0.15); }

.feature-section { min-height: 100vh; }
.section-alt { background: var(--bg2); }
.mesh-orb { position: absolute; border-radius: 50%; filter: blur(100px); pointer-events: none; z-index: 0; }

/* Reveals — başlangıç durumu JS (GSAP) tarafından verilir.
   CSS'te opacity:0 verilmez ki JS yüklenmezse içerik görünür kalsın. */

/* Glass Card */
.glass-card {
  background: var(--surface2); border: 1px solid var(--border);
  backdrop-filter: blur(16px); border-radius: 24px;
  transition: all 0.5s var(--ease);
}
.glass-card:hover {
  background: var(--surface3); border-color: var(--border2);
  box-shadow: 0 20px 50px -12px rgba(0,0,0,0.4); transform: translateY(-4px);
}
.card-shine { position: relative; overflow: hidden; }
.card-shine::after {
  content: ''; position: absolute; width: 200%; height: 200%; top: -50%; left: -50%;
  background: radial-gradient(circle at var(--mx, 50%) var(--my, 50%), rgba(255,255,255,0.06) 0%, transparent 50%);
  pointer-events: none; opacity: 0; transition: opacity 0.3s ease;
}
.card-shine:hover::after { opacity: 1; }
.tilt-card { perspective: 900px; transform-style: preserve-3d; }

/* Metric */
.metric-value {
  background: linear-gradient(135deg, #4A90E2, #85C2FF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.teacher-page .metric-value {
  background: linear-gradient(135deg, #00E676, #69F0AE);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

/* CTA Button */
.cta-btn { position: relative; overflow: hidden; transition: all 0.4s var(--ease); }
.cta-btn::before { content: ''; position: absolute; inset: 0; background: linear-gradient(135deg, rgba(255,255,255,0.15), transparent); opacity: 0; transition: opacity 0.3s ease; }
.cta-btn:hover::before { opacity: 1; }
.cta-btn:hover { transform: translateY(-2px); box-shadow: 0 12px 30px -8px var(--blue-glow); }
.cta-btn-teacher:hover { box-shadow: 0 12px 30px -8px var(--green-glow); }

.btn-secondary {
  background: var(--surface3); border: 1px solid var(--border2);
  backdrop-filter: blur(10px); transition: all 0.3s var(--ease);
}
.btn-secondary:hover { background: rgba(255,255,255,0.12); border-color: rgba(255,255,255,0.18); }

/* Dot Nav */
.dot-nav { position: fixed; right: 2rem; top: 50%; transform: translateY(-50%); z-index: 40; display: flex; flex-direction: column; gap: 12px; }
.dot-nav-item { width: 10px; height: 10px; border-radius: 50%; background: rgba(255,255,255,0.15); cursor: pointer; transition: all 0.3s ease; }
.dot-nav-item.active { background: var(--blue); transform: scale(1.3); box-shadow: 0 0 12px var(--blue-glow); }
.teacher-page .dot-nav-item.active { background: var(--green); box-shadow: 0 0 12px var(--green-glow); }

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.10); border-radius: 3px; }

.back-btn { position: fixed; top: 1.5rem; left: 1.5rem; z-index: 60; opacity: 0; visibility: hidden; transition: all 0.4s ease; }
.back-btn.visible { opacity: 1; visibility: visible; }

.browser-mockup {
  max-width: 600px; margin: 0 auto; border-radius: 16px; overflow: hidden;
  box-shadow: 0 25px 60px -12px rgba(0,0,0,0.5), 0 0 0 1px rgba(255,255,255,0.06);
}

.stat-card {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: 20px; padding: 1.5rem; text-align: center;
  transition: all 0.4s var(--ease);
}
.stat-card:hover { background: var(--surface3); border-color: var(--border2); transform: translateY(-2px); }
.stat-number { font-variant-numeric: tabular-nums; }

.feature-item { display: flex; align-items: flex-start; gap: 1rem; padding: 0.75rem 0; }
.feature-icon { width: 44px; height: 44px; border-radius: 14px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.feature-icon-blue { background: rgba(74,144,226,0.12); border: 1px solid rgba(74,144,226,0.15); }
.feature-icon-green { background: rgba(0,230,118,0.10); border: 1px solid rgba(0,230,118,0.12); }

.tag { background: var(--surface3); border: 1px solid var(--border2); padding: 0.5rem 1rem; border-radius: 999px; font-size: 0.85rem; font-weight: 500; color: var(--t2); transition: all 0.3s ease; }
.tag:hover { background: rgba(255,255,255,0.10); color: var(--t1); }

/* Homework form */
.hw-form { background: var(--surface2); border: 1px solid var(--border); backdrop-filter: blur(20px); border-radius: 24px; padding: 2rem; }
.hw-field { background: var(--surface3); border: 1px solid var(--border); border-radius: 14px; padding: 0.85rem 1rem; font-size: 0.9rem; font-weight: 500; color: var(--t1); }

/* Report Card */
.report-card {
  background: var(--surface2); border: 1px solid var(--border); border-radius: 20px; padding: 1.75rem;
  backdrop-filter: blur(10px); transition: all 0.4s var(--ease);
}
.report-card:hover { background: var(--surface3); border-color: var(--border2); transform: translateY(-4px); box-shadow: 0 20px 50px -12px rgba(0,0,0,0.3); }

/* Problem Card */
.problem-card {
  background: var(--surface2); border: 1px solid var(--border); border-radius: 20px; padding: 2rem;
  backdrop-filter: blur(10px); transition: all 0.4s var(--ease);
}
.problem-card:hover { background: var(--surface3); transform: translateY(-4px); }
.problem-card.pc-blue:hover { border-color: rgba(74,144,226,0.3); box-shadow: 0 0 40px rgba(74,144,226,0.08); }
.problem-card.pc-green:hover { border-color: rgba(0,230,118,0.3); box-shadow: 0 0 40px rgba(0,230,118,0.08); }
.problem-card.pc-orange:hover { border-color: rgba(255,167,38,0.3); box-shadow: 0 0 40px rgba(255,167,38,0.08); }

/* How-it-works step */
.step-card {
  display: grid; grid-template-columns: 1fr 1.2fr; gap: 3rem; align-items: center;
  padding: 3rem 0; border-bottom: 1px solid var(--border);
}
.step-card:last-child { border-bottom: none; }
.step-card.reverse { direction: rtl; }
.step-card.reverse > * { direction: ltr; }
.step-num {
  font-size: 4rem; font-weight: 800; line-height: 1; letter-spacing: -3px; margin-bottom: 1rem;
  background: linear-gradient(135deg, rgba(74,144,226,0.15), rgba(74,144,226,0.05));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.step-phone-screen {
  border-radius: 20px; overflow: hidden; aspect-ratio: 9/16;
  box-shadow: 0 28px 70px rgba(0,0,0,0.5), 0 0 50px var(--blue-glow);
  max-width: 280px; margin: 0 auto;
}
.step-phone-screen img { width: 100%; height: 100%; object-fit: cover; }

/* App Preview */
.preview-card {
  background: var(--surface2); border: 1px solid var(--border); border-radius: 24px;
  overflow: hidden; transition: all 0.4s var(--ease);
}
.preview-card:hover { transform: translateY(-8px); border-color: rgba(74,144,226,0.2); box-shadow: 0 30px 60px rgba(0,0,0,0.4), 0 0 40px rgba(74,144,226,0.08); }
.preview-img { aspect-ratio: 9/16; overflow: hidden; }
.preview-img img { width: 100%; height: 100%; object-fit: cover; }

/* Testimonial */
.testi-card {
  background: var(--surface2); border: 1px solid var(--border); border-radius: 20px; padding: 2rem;
  transition: all 0.4s var(--ease);
}
.testi-card:hover { background: var(--surface3); border-color: var(--border2); transform: translateY(-4px); }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  width: 100%; text-align: left; display: flex; justify-content: space-between; align-items: center;
  padding: 1.4rem 0; gap: 1rem; font-size: 1rem; font-weight: 600; color: var(--t1);
  cursor: pointer; background: none; transition: color 0.2s;
}
.faq-q:hover { color: var(--blue); }
.faq-arrow {
  width: 32px; height: 32px; border-radius: 50%; background: var(--surface3); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center; font-size: 0.85rem; flex-shrink: 0;
  transition: transform 0.3s, background 0.2s;
}
.faq-item.open .faq-arrow { transform: rotate(45deg); background: var(--blue); border-color: var(--blue); }
.teacher-page .faq-item.open .faq-arrow { background: var(--green); border-color: var(--green); }
.faq-a {
  font-size: 0.93rem; color: var(--t2); line-height: 1.75;
  overflow: hidden; max-height: 0; transition: max-height 0.4s var(--ease), padding 0.3s;
}
.faq-item.open .faq-a { max-height: 200px; padding-bottom: 1.25rem; }

/* Footer Rich */
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr 1fr; gap: 3rem; }
.footer-col-title { font-size: 0.75rem; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; color: var(--t3); margin-bottom: 1.25rem; }
.footer-links { display: flex; flex-direction: column; gap: 0.75rem; }
.footer-links a { font-size: 0.88rem; color: var(--t2); transition: color 0.2s; }
.footer-links a:hover { color: var(--t1); }

/* Responsive */
@media (max-width: 1024px) {
  .step-card { grid-template-columns: 1fr; gap: 2rem; }
  .step-card.reverse { direction: ltr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .phone-mockup { width: 220px; }
  .phone-frame { border-radius: 32px; padding: 10px; }
  .phone-screen { border-radius: 24px; }
  .phone-notch { width: 100px; height: 24px; }
  .dot-nav { display: none; }
  .splash-mesh { opacity: 0.6; }
  .step-card { padding: 2rem 0; }
  .footer-grid { grid-template-columns: 1fr; }
  .splash-screen { align-items: flex-start; overflow-y: auto; padding: 1.5rem 0 2rem; }
  .role-card-inner { padding: 1.5rem 1.25rem; }
  .role-card-inner, .main-nav, .report-card, .problem-card, .hw-form, .testi-card { backdrop-filter: none !important; -webkit-backdrop-filter: none !important; }
}
@media (max-width: 480px) {
  .phone-mockup { width: 180px; }
  .splash-screen { padding: 1rem 0 1.5rem; }
  .role-card-inner { padding: 1.25rem 1rem; }
}

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

/* ── Splash (index.php) ek stiller ── */
@keyframes splashUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}
.splash-anim   { animation: splashUp 0.9s cubic-bezier(.22,1,.36,1) both; }
.splash-anim-2 { animation: splashUp 0.9s cubic-bezier(.22,1,.36,1) 0.15s both; }
.splash-anim-3 { animation: splashUp 0.9s cubic-bezier(.22,1,.36,1) 0.3s both; }
.splash-anim-4 { animation: splashUp 0.9s cubic-bezier(.22,1,.36,1) 0.45s both; }
@media (prefers-reduced-motion: reduce) {
  .splash-anim, .splash-anim-2, .splash-anim-3, .splash-anim-4 { animation: none; }
}

/* Splash üst bar */
.splash-topbar {
  position: absolute; top: 0; left: 0; right: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  max-width: 80rem; margin: 0 auto; padding: 1.1rem 1.5rem;
}
.splash-topbar-links { display: flex; align-items: center; gap: 1.5rem; font-size: 0.9rem; }
.splash-topbar-links a { color: rgba(255,255,255,0.65); transition: color 0.2s; }
.splash-topbar-links a:hover { color: #fff; }
.splash-topbar-links a.tb-cta {
  color: #fff; font-weight: 600; padding: 0.45rem 1.1rem; border-radius: 999px;
  background: rgba(74,144,226,0.15); border: 1px solid rgba(74,144,226,0.35);
}
.splash-topbar-links a.tb-cta:hover { background: rgba(74,144,226,0.30); }
@media (max-width: 640px) {
  .splash-topbar { padding: 0.9rem 1rem; }
  .splash-topbar-links { gap: 1rem; font-size: 0.82rem; }
  .splash-topbar .tb-brand-name { display: none; }
}

/* Tekrar hoş geldin çipi */
.welcome-back-chip {
  display: none; margin: 0 auto 1.25rem; max-width: fit-content;
  align-items: center; gap: 8px; padding: 8px 16px; border-radius: 999px;
  font-size: 0.85rem; font-weight: 600; color: #fff;
  background: rgba(0,230,118,0.10); border: 1px solid rgba(0,230,118,0.30);
  transition: background 0.2s;
}
.welcome-back-chip:hover { background: rgba(0,230,118,0.20); }
.welcome-back-chip.show { display: inline-flex; }

/* Splash mini footer */
.splash-footer {
  position: relative; z-index: 10; margin-top: 2.5rem; padding-top: 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.06);
  display: flex; flex-wrap: wrap; justify-content: center; gap: 1.25rem;
  font-size: 0.8rem; color: rgba(255,255,255,0.35);
}
.splash-footer a { color: rgba(255,255,255,0.45); transition: color 0.2s; }
.splash-footer a:hover { color: #fff; }