/* ── Shared Learn styles — matches main site glass aesthetic ── */
@layer reset, base, components, utilities;

@layer reset {
  *, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body { min-height: 100vh; }
  img, svg { display: block; max-width: 100%; }
  a { color: inherit; text-decoration: none; }
}

@layer base {
  :root {
    --bg-deep: #070b1a;
    --bg-glass: rgba(255,255,255,0.04);
    --bg-glass-hover: rgba(255,255,255,0.08);
    --border-glass: rgba(255,255,255,0.06);
    --border-glass-hover: rgba(255,255,255,0.12);
    --accent: #2dd4bf;
    --accent-dim: rgba(45,212,191,0.3);
    --accent-glow: rgba(45,212,191,0.08);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #475569;
    --radius: 12px;
    --radius-sm: 8px;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --nav-height: 72px;
  }

  body {
    font-family: var(--font);
    background: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
  }

  body::before {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -2;
    background:
      radial-gradient(ellipse 70% 50% at 10% 5%, rgba(45,212,191,0.1) 0%, transparent 55%),
      radial-gradient(ellipse 50% 70% at 90% 85%, rgba(99,102,241,0.08) 0%, transparent 55%),
      radial-gradient(ellipse 40% 40% at 50% 50%, rgba(139,92,246,0.05) 0%, transparent 50%);
    animation: orbDrift 35s ease-in-out infinite alternate;
  }

  body::after {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -1;
    background-image:
      radial-gradient(ellipse 50% 40% at 70% 20%, rgba(45,212,191,0.06) 0%, transparent 50%),
      radial-gradient(ellipse 40% 60% at 20% 70%, rgba(167,139,250,0.05) 0%, transparent 50%),
      linear-gradient(rgba(255,255,255,0.01) 1px, transparent 1px),
      linear-gradient(90deg, rgba(255,255,255,0.01) 1px, transparent 1px);
    background-size: auto, auto, 64px 64px, 64px 64px;
    animation: orbDriftReverse 40s ease-in-out infinite alternate;
  }

  @keyframes orbDrift {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(3%, -3%) scale(1.05); }
    100% { transform: translate(-1%, 1%) scale(0.97); }
  }

  @keyframes orbDriftReverse {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(-2%, 2%) scale(1.04); }
    100% { transform: translate(1%, -1%) scale(0.98); }
  }
}

@layer components {
  .nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: rgba(7,11,26,0.6);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-glass);
    height: var(--nav-height);
    display: flex; align-items: center;
  }
  .nav-inner {
    width: 100%; max-width: 1200px; margin: 0 auto;
    padding: 0 32px;
    display: flex; align-items: center; justify-content: space-between;
  }
  .nav-brand { font-size: 1.05rem; font-weight: 700; letter-spacing: -0.02em; color: var(--text-primary); }
  .nav-brand span {
    background: linear-gradient(135deg, var(--accent), #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
  }

  .container { max-width: 800px; margin: 0 auto; padding: 0 24px; }

  .page-wrap {
    padding: calc(var(--nav-height) + 48px) 0 64px;
  }

  .breadcrumb {
    font-size: .8rem; color: var(--text-muted); margin-bottom: 24px;
  }
  .breadcrumb a { color: var(--accent); }
  .breadcrumb a:hover { opacity: .7; }
  .breadcrumb span { color: var(--text-secondary); }

  .content-card {
    position: relative;
    background: linear-gradient(135deg, rgba(255,255,255,0.04) 0%, rgba(255,255,255,0.02) 100%);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    padding: 48px 40px;
    isolation: isolate;
    transition: border-color .4s;
  }

  .content-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, transparent 0%, var(--accent) 25%, #818cf8 50%, #a78bfa 75%, transparent 100%);
    background-size: 200% 100%;
    animation: gradientBar 4s ease-in-out infinite;
    border-radius: var(--radius) var(--radius) 0 0;
    pointer-events: none;
    z-index: 1;
  }

  .content-card::after {
    content: '';
    position: absolute;
    inset: -1px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, rgba(45,212,191,0.06) 0%, rgba(99,102,241,0.04) 50%, transparent 100%);
    opacity: 0;
    transition: opacity .6s ease;
    pointer-events: none;
    z-index: -1;
  }

  .content-card:hover::after {
    opacity: 1;
  }

  @keyframes gradientBar {
    0% { background-position: 0% 0%; }
    50% { background-position: 100% 0%; }
    100% { background-position: 0% 0%; }
  }

  .content-card h1 {
    font-size: 2rem; font-weight: 800; letter-spacing: -0.02em;
    line-height: 1.15; margin-bottom: 8px;
  }

  .content-card .page-desc {
    font-size: 1.05rem; color: var(--text-secondary);
    margin-bottom: 32px; line-height: 1.6;
  }

  .content-card h2 {
    font-size: 1.3rem; font-weight: 700; letter-spacing: -0.01em;
    margin-top: 36px; margin-bottom: 12px; color: var(--text-primary);
  }

  .content-card h3 {
    font-size: 1.05rem; font-weight: 600;
    margin-top: 24px; margin-bottom: 8px; color: var(--text-primary);
  }

  .content-card p {
    margin-bottom: 16px; color: var(--text-secondary); font-size: .95rem;
  }

  .content-card ul, .content-card ol {
    margin-bottom: 16px; padding-left: 24px; color: var(--text-secondary); font-size: .95rem;
  }
  .content-card li { margin-bottom: 6px; }

  .content-card strong { color: var(--text-primary); font-weight: 600; }

  .content-card code {
    background: rgba(45,212,191,0.08);
    padding: 2px 8px; border-radius: 4px;
    font-size: .85rem; color: #5eead4;
    border: 1px solid rgba(45,212,191,0.1);
  }

  .content-card hr {
    border: none; border-top: 1px solid var(--border-glass);
    margin: 36px 0;
  }

  .highlight-box {
    position: relative;
    background: linear-gradient(135deg, rgba(45,212,191,0.08) 0%, rgba(99,102,241,0.04) 100%);
    border: 1px solid rgba(45,212,191,0.15);
    border-radius: var(--radius-sm);
    padding: 20px 24px;
    margin-bottom: 20px;
    overflow: hidden;
  }
  .highlight-box::before {
    content: '';
    position: absolute;
    left: 0; top: 0;
    width: 3px;
    height: 100%;
    background: linear-gradient(180deg, var(--accent), #818cf8);
  }
  .highlight-box p { margin-bottom: 0; }
  .highlight-box strong { color: var(--accent); }

  .tag {
    display: inline-block;
    font-size: .65rem; font-weight: 600; text-transform: uppercase;
    letter-spacing: .06em;
    padding: 4px 10px; border-radius: 4px;
    margin-bottom: 16px;
  }
  .tag-security { background: rgba(248,113,113,0.1); color: #f87171; }
  .tag-seo { background: rgba(45,212,191,0.1); color: var(--accent); }
  .tag-performance { background: rgba(251,191,36,0.1); color: #fbbf24; }
  .tag-mobile { background: rgba(99,102,241,0.1); color: #818cf8; }
  .tag-design { background: rgba(167,139,250,0.1); color: #a78bfa; }
  .tag-content { background: rgba(248,113,113,0.1); color: #f87171; }
  .tag-business { background: rgba(52,211,153,0.1); color: #34d399; }

  .related-topics {
    margin-top: 36px; padding-top: 24px;
    border-top: 1px solid var(--border-glass);
  }
  .related-topics h3 {
    font-size: .85rem; font-weight: 600; color: var(--text-muted);
    text-transform: uppercase; letter-spacing: .06em;
    margin-bottom: 16px;
  }
  .related-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }
  .related-grid a {
    display: block;
    padding: 10px 14px;
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-sm);
    font-size: .85rem;
    color: var(--text-secondary);
    transition: background .2s, border-color .2s, color .2s;
  }
  .related-grid a:hover {
    background: var(--bg-glass-hover);
    border-color: var(--border-glass-hover);
    color: var(--text-primary);
  }

  .cta-section {
    margin-top: 48px;
    text-align: center;
    padding: 40px;
    background: linear-gradient(135deg, rgba(45,212,191,0.06) 0%, rgba(99,102,241,0.03) 100%);
    border: 1px solid rgba(45,212,191,0.12);
    border-radius: var(--radius);
  }
  .cta-section h3 {
    font-size: 1.15rem; font-weight: 700; margin-bottom: 8px;
  }
  .cta-section p {
    color: var(--text-secondary); font-size: .9rem; margin-bottom: 20px;
  }
  .cta-btn {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--accent); color: #070b1a;
    font-weight: 700; font-size: .9rem;
    padding: 12px 28px; border-radius: var(--radius-sm);
    transition: transform .2s, box-shadow .2s;
  }
  .cta-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 32px rgba(45,212,191,0.2);
  }

  footer {
    padding: 32px 0;
    border-top: 1px solid var(--border-glass);
    text-align: center;
  }
  footer p { font-size: .8rem; color: var(--text-muted); }
  footer a { color: var(--accent); }
  footer a:hover { opacity: .7; }

  footer .footer-learn-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--text-secondary);
    transition: color .2s;
  }
  footer .footer-learn-link:hover {
    color: var(--accent);
  }
}

@layer utilities {
  .flex { display: flex; }
  .flex-wrap { flex-wrap: wrap; }
  .gap-sm { gap: 8px; }
  .mb-md { margin-bottom: 16px; }
}

@media (max-width: 600px) {
  .content-card { padding: 32px 20px; }
  .content-card h1 { font-size: 1.5rem; }
  .related-grid { grid-template-columns: 1fr; }
  .cta-section { padding: 24px 20px; }

  .pulse-nav {
    bottom: 24px;
    right: 16px;
  }
  .pulse-btn {
    width: 54px;
    height: 54px;
  }
  .pulse-btn svg {
    width: 20px;
    height: 20px;
  }
  .pulse-menu {
    right: 0;
    min-width: 190px;
  }
}

/* ── Pulse Navigation ── */
.pulse-nav {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 200;
}

.pulse-btn {
  position: relative;
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: rgba(7,11,26,0.7);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(45,212,191,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: transform .3s cubic-bezier(.22,1,.36,1), border-color .3s;
  z-index: 2;
  box-shadow: 0 4px 24px rgba(0,0,0,0.3);
}

.pulse-btn:hover {
  transform: scale(1.05);
  border-color: rgba(45,212,191,0.4);
}

.pulse-btn svg {
  width: 22px;
  height: 22px;
  color: var(--accent);
}

.pulse-btn.open svg {
  opacity: .6;
}

.pulse-ring {
  position: absolute;
  inset: -8px;
  border-radius: 50%;
  border: 2px solid rgba(45,212,191,0.15);
  animation: pulseRing 3s ease-out infinite;
  pointer-events: none;
}

.pulse-ring:nth-child(2) {
  animation-delay: 1.5s;
}

@keyframes pulseRing {
  0% { transform: scale(1); opacity: .6; }
  50% { transform: scale(1.35); opacity: .2; }
  100% { transform: scale(1.7); opacity: 0; }
}

.pulse-menu {
  position: absolute;
  bottom: 68px;
  right: 4px;
  min-width: 210px;
  background: rgba(7,11,26,0.8);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--border-glass);
  border-radius: 16px;
  padding: 12px 8px;
  opacity: 0;
  transform: translateY(12px) scale(0.95);
  pointer-events: none;
  transition: opacity .3s ease, transform .3s cubic-bezier(.22,1,.36,1);
  box-shadow: 0 12px 48px rgba(0,0,0,0.4);
}

.pulse-menu.open {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.pulse-menu a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 10px;
  font-size: .9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: background .2s, color .2s;
  opacity: 0;
  transform: translateY(8px);
  transition: background .2s, color .2s, opacity .25s ease, transform .25s ease;
}

.pulse-menu.open a {
  opacity: 1;
  transform: translateY(0);
}

.pulse-menu.open a:nth-child(1) { transition-delay: 0.05s; }
.pulse-menu.open a:nth-child(2) { transition-delay: 0.10s; }
.pulse-menu.open a:nth-child(3) { transition-delay: 0.15s; }

.pulse-menu a:hover {
  background: rgba(255,255,255,0.06);
  color: var(--text-primary);
}

.pulse-menu a svg {
  width: 18px;
  height: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.pulse-menu .menu-divider {
  height: 1px;
  background: var(--border-glass);
  margin: 6px 16px;
  opacity: 0;
  transition: opacity .2s ease;
  transition-delay: 0.12s;
}

.pulse-menu.open .menu-divider {
  opacity: 1;
}

.pulse-overlay {
  position: fixed;
  inset: 0;
  z-index: 199;
  background: rgba(0,0,0,0.3);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s ease;
}

.pulse-overlay.open {
  opacity: 1;
  pointer-events: all;
}

/* ── Scroll reveal for content sections ── */
.content-card p,
.content-card h2,
.content-card h3 {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .5s ease, transform .5s ease;
}
.content-card p.visible,
.content-card h2.visible,
.content-card h3.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── H2 animated underline ── */
.content-card h2 {
  position: relative;
  display: inline-block;
}
.content-card h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), #818cf8);
  transition: width .6s cubic-bezier(.22,1,.36,1);
}
.content-card h2.revealed::after {
  width: 100%;
}

/* ── Highlight box pulse on scroll ── */
.highlight-box {
  transition: background .5s ease, border-color .5s ease;
}
.highlight-box.scrolled {
  background: linear-gradient(135deg, rgba(45,212,191,0.12) 0%, rgba(99,102,241,0.06) 100%);
  border-color: rgba(45,212,191,0.25);
}

@media (prefers-reduced-motion: reduce) {
  .pulse-ring { display: none; }
  .content-card p,
  .content-card h2,
  .content-card h3 { opacity: 1; transform: none; }
}