/* ── RESET & BASE ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', sans-serif;
  background: #F8F9FC;
  color: #1A1F36;
  line-height: 1.6;
  overflow-x: hidden;
}

/* ── TOKENS ── */
:root {
  --navy: #1A1F36;
  --blue: #2C3E7A;
  --sky: #0EA5E9;
  --green: #10B981;
  --light: #F8F9FC;
  --mid: #EEF0F7;
  --muted: #6B7280;
  --white: #ffffff;
  --radius: 14px;
  --shadow: 0 4px 24px rgba(26,31,54,0.10);
  --shadow-lg: 0 12px 48px rgba(26,31,54,0.16);
}

/* ── NAV ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(248,249,252,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(44,62,122,0.08);
}
.nav-inner {
  max-width: 1200px; margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex; align-items: center; gap: 32px;
}
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-mark {
  width: 36px; height: 36px;
  display: block;
  object-fit: contain;
  flex-shrink: 0;
}
.logo-text {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700; font-size: 18px;
  color: var(--navy);
}
.nav-links {
  display: flex; gap: 28px; list-style: none; margin-left: auto;
}
.nav-links a {
  color: var(--muted); text-decoration: none;
  font-size: 14px; font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--navy); }
.nav-cta { display: flex; gap: 10px; align-items: center; }

/* ── BUTTONS ── */
.btn-primary {
  background: var(--blue); color: white;
  padding: 10px 22px; border-radius: 8px;
  text-decoration: none; font-size: 14px; font-weight: 600;
  transition: all 0.2s; border: none; cursor: pointer;
  font-family: 'Space Grotesk', sans-serif;
  display: inline-block;
}
.btn-primary:hover { background: #1e2d5e; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-ghost {
  color: var(--navy); text-decoration: none;
  font-size: 14px; font-weight: 500;
  padding: 10px 18px; border-radius: 8px;
  transition: background 0.2s;
  display: inline-block;
}
.btn-ghost:hover { background: var(--mid); }
.btn-outline {
  border: 2px solid var(--blue); color: var(--blue);
  text-decoration: none; font-size: 14px; font-weight: 600;
  padding: 10px 22px; border-radius: 8px;
  transition: all 0.2s; display: inline-block;
  font-family: 'Space Grotesk', sans-serif;
}
.btn-outline:hover { background: var(--blue); color: white; }
.btn-large { padding: 14px 32px; font-size: 16px; border-radius: 10px; }
.btn-block { display: block; text-align: center; width: 100%; }

/* ── HERO ── */
.hero {
  min-height: 100vh;
  padding-top: 64px;
  display: flex; align-items: center;
  background: linear-gradient(135deg, #F8F9FC 0%, #EEF2FF 100%);
  overflow: hidden;
  position: relative;
}
.hero::before {
  content: '';
  position: absolute;
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(14,165,233,0.08) 0%, transparent 70%);
  top: 0; right: 0; pointer-events: none;
}
.hero-inner {
  max-width: 580px;
  padding: 80px 0 80px 80px;
  flex-shrink: 0;
}
.hero-badge {
  display: inline-block;
  background: rgba(44,62,122,0.08);
  color: var(--blue);
  padding: 6px 14px; border-radius: 99px;
  font-size: 13px; font-weight: 600;
  margin-bottom: 24px;
  letter-spacing: 0.3px;
}
.hero-headline {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(42px, 5vw, 64px);
  font-weight: 700;
  line-height: 1.05;
  color: var(--navy);
  margin-bottom: 24px;
}
.accent { color: var(--blue); }
.hero-sub {
  font-size: 18px; color: var(--muted);
  line-height: 1.7; margin-bottom: 36px;
  max-width: 440px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 48px; }
.hero-stats {
  display: flex; align-items: center; gap: 20px; flex-wrap: wrap;
}
.stat { display: flex; flex-direction: column; }
.stat-num {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700; font-size: 20px; color: var(--navy);
}
.stat-label { font-size: 12px; color: var(--muted); }
.stat-divider { width: 1px; height: 36px; background: rgba(44,62,122,0.15); }

/* ── HERO VISUAL ── */
.hero-visual {
  flex: 1;
  display: flex; align-items: center; justify-content: center;
  padding: 80px 40px;
  min-width: 0;
}
.board-mockup {
  background: white;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  width: 100%; max-width: 580px;
  border: 1px solid rgba(44,62,122,0.08);
}
.board-bar {
  background: var(--navy);
  padding: 12px 16px;
  display: flex; align-items: center; gap: 8px;
}
.board-dot { width: 12px; height: 12px; border-radius: 50%; }
.board-dot.red { background: #FF5F57; }
.board-dot.yellow { background: #FFBD2E; }
.board-dot.green { background: #28C840; }
.board-title {
  margin-left: 8px; color: rgba(255,255,255,0.6);
  font-size: 13px; font-family: 'Space Grotesk', sans-serif;
}
.board-content { display: flex; }
.board-canvas {
  flex: 1; padding: 24px;
  background: #FAFBFF;
  min-height: 280px;
}
.board-drawing { width: 100%; height: auto; }
.board-sidebar {
  width: 130px;
  background: white;
  border-left: 1px solid var(--mid);
  padding: 16px 12px;
  display: flex; flex-direction: column; gap: 12px;
}
.participant { display: flex; align-items: center; gap: 8px; }
.participant-avatar {
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 11px; font-weight: 700; color: white;
  flex-shrink: 0;
}
.participant-avatar.tutor { background: var(--blue); }
.participant-avatar.student { background: var(--sky); }
.participant-info { display: flex; flex-direction: column; flex: 1; min-width: 0; }
.participant-name { font-size: 11px; font-weight: 600; color: var(--navy); }
.participant-role { font-size: 10px; color: var(--muted); }
.participant-status {
  font-size: 9px; font-weight: 700; border-radius: 4px;
  padding: 2px 5px; flex-shrink: 0;
}
.participant-status.live { background: #FEE2E2; color: #EF4444; }
.participant-status.connected { background: #DCFCE7; color: #16A34A; }
.board-tools {
  display: flex; gap: 6px; flex-wrap: wrap; margin-top: 4px;
}
.tool {
  width: 28px; height: 28px; border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; background: var(--mid); cursor: pointer;
  transition: background 0.2s;
}
.tool.active { background: var(--blue); }
.session-timer {
  margin-top: auto;
  text-align: center;
  background: var(--mid); border-radius: 8px; padding: 8px 4px;
}
.timer-label { display: block; font-size: 10px; color: var(--muted); }
.timer-val {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px; font-weight: 700; color: var(--navy);
}

/* ── CONTAINER ── */
.container { max-width: 1100px; margin: 0 auto; padding: 0 32px; }

/* ── SECTIONS ── */
.section-label {
  font-size: 12px; font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; color: var(--sky);
  margin-bottom: 12px;
}
.section-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(30px, 3.5vw, 44px);
  font-weight: 700; color: var(--navy);
  margin-bottom: 48px; line-height: 1.15;
}

/* ── FEATURES ── */
.features { padding: 100px 0; background: white; }
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--light);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid rgba(44,62,122,0.06);
  transition: all 0.2s;
}
.feature-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.feature-card--highlight {
  background: var(--blue); color: white;
  border-color: transparent;
}
.feature-card--highlight h3 { color: white; }
.feature-card--highlight p { color: rgba(255,255,255,0.75); }
.feature-icon { font-size: 28px; margin-bottom: 16px; }
.feature-card h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px; font-weight: 700;
  color: var(--navy); margin-bottom: 10px;
}
.feature-card p { font-size: 14px; color: var(--muted); line-height: 1.65; }

/* ── HOW IT WORKS ── */
.how { padding: 100px 0; background: var(--light); }
.steps {
  display: flex; align-items: flex-start; gap: 0;
  flex-wrap: wrap;
}
.step {
  flex: 1; min-width: 200px;
  display: flex; flex-direction: column; gap: 16px;
}
.step-num {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 40px; font-weight: 700;
  color: rgba(44,62,122,0.12);
  line-height: 1;
}
.step-content h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 20px; font-weight: 700; color: var(--navy);
  margin-bottom: 8px;
}
.step-content p { font-size: 15px; color: var(--muted); line-height: 1.65; }
.step-line {
  width: 60px; height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--sky));
  margin-top: 20px; flex-shrink: 0;
  align-self: flex-start;
}

/* ── PRICING ── */
.pricing { padding: 100px 0; background: white; }
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.pricing-card {
  background: var(--light);
  border-radius: var(--radius);
  padding: 36px 32px;
  border: 1px solid rgba(44,62,122,0.08);
  position: relative;
  transition: all 0.2s;
}
.pricing-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.pricing-card--pro {
  background: var(--navy); color: white;
  border-color: transparent;
  box-shadow: var(--shadow-lg);
}
.pricing-card--pro .plan-name,
.pricing-card--pro .plan-price,
.pricing-card--pro .plan-desc { color: white; }
.pricing-card--pro .plan-features li { color: rgba(255,255,255,0.75); }
.pricing-card--pro .plan-features li::before { color: var(--sky); }
.plan-badge {
  display: inline-block;
  background: var(--sky); color: white;
  font-size: 11px; font-weight: 700;
  padding: 4px 10px; border-radius: 99px;
  margin-bottom: 12px; letter-spacing: 0.5px;
}
.plan-name {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 20px; font-weight: 700; color: var(--navy);
  margin-bottom: 8px;
}
.plan-price { display: flex; align-items: baseline; gap: 4px; margin-bottom: 6px; }
.price-num {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 40px; font-weight: 700; color: var(--navy);
}
.price-period { font-size: 16px; color: var(--muted); }
.plan-desc { font-size: 13px; color: var(--muted); margin-bottom: 24px; }
.plan-features {
  list-style: none; margin-bottom: 28px;
  display: flex; flex-direction: column; gap: 10px;
}
.plan-features li {
  font-size: 14px; color: var(--muted);
  display: flex; align-items: center; gap: 10px;
}
.plan-features li::before { content: '✓'; font-weight: 700; color: var(--green); }

/* ── CTA ── */
.cta-section {
  padding: 100px 32px;
  background: var(--blue);
  text-align: center;
}
.cta-section h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700; color: white; margin-bottom: 16px;
}
.cta-section p { font-size: 18px; color: rgba(255,255,255,0.7); margin-bottom: 36px; }
.cta-section .btn-primary {
  background: white; color: var(--blue);
}
.cta-section .btn-primary:hover { background: var(--mid); }

/* ── FOOTER ── */
.footer { padding: 40px 0; background: var(--navy); }
.footer-inner {
  display: flex; align-items: center;
  flex-wrap: wrap; gap: 20px;
}
.footer .logo-text { color: white; }
.footer-links { display: flex; gap: 24px; margin-left: auto; }
.footer-links a { color: rgba(255,255,255,0.5); text-decoration: none; font-size: 14px; }
.footer-links a:hover { color: white; }
.footer-copy { font-size: 13px; color: rgba(255,255,255,0.3); width: 100%; }

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .hero { flex-direction: column; min-height: auto; }
  .hero-inner { padding: 100px 32px 40px; max-width: 100%; }
  .hero-visual { padding: 0 32px 60px; }
  .nav-links { display: none; }
  .steps { flex-direction: column; }
  .step-line { width: 2px; height: 40px; margin: 0 0 0 19px; }
}

@media (max-width: 600px) {
  .hero-inner { padding: 100px 20px 32px; }
  .hero-visual { padding: 0 20px 48px; }
  .container { padding: 0 20px; }
  .features, .how, .pricing { padding: 64px 0; }
  .hero-stats { gap: 14px; }
  .footer-inner { flex-direction: column; text-align: center; }
  .footer-links { margin-left: 0; }
}

/* ── LOGO VARIANTS ── */
.auth-logo .logo-mark { width: 44px; height: 44px; }
.footer .logo-mark { width: 32px; height: 32px; }