/* Learn AI Engineering — public pages */
.learn-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 14, 39, 0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(212, 175, 55, 0.15);
}

.learn-nav__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.learn-nav__logo {
  font-family: 'Playfair Display', serif;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--luxury-gold, #D4AF37);
  text-decoration: none;
  letter-spacing: 0.05em;
}

.learn-nav__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.learn-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  border-radius: 50px;
  border: 1px solid rgba(212, 175, 55, 0.3);
  background: rgba(212, 175, 55, 0.08);
  color: var(--pearl-white, #F8F9FA);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.3s ease;
}

.learn-back-btn:hover {
  background: rgba(212, 175, 55, 0.2);
  border-color: var(--luxury-gold, #D4AF37);
  transform: translateX(-3px);
}

.learn-page {
  padding-top: 80px;
  min-height: 100vh;
}

.learn-hero {
  text-align: center;
  padding: 3rem 1.5rem 2rem;
  max-width: 800px;
  margin: 0 auto;
}

.learn-hero h1 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  background: linear-gradient(135deg, #fff 0%, var(--luxury-gold, #D4AF37) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}

.learn-hero p {
  color: var(--platinum, #E5E4E2);
  font-size: 1.1rem;
  line-height: 1.7;
}

.learn-sections {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.learn-module {
  margin-bottom: 2.5rem;
  scroll-margin-top: 100px;
  background: linear-gradient(135deg, rgba(255,255,255,0.03) 0%, rgba(212,175,55,0.03) 100%);
  border: 1px solid rgba(212, 175, 55, 0.2);
  border-radius: 20px;
  overflow: hidden;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.learn-module:hover {
  border-color: rgba(212, 175, 55, 0.4);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
}

.learn-module__head {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem 1.75rem;
  border-bottom: 1px solid rgba(212, 175, 55, 0.1);
}

.learn-module__icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  background: linear-gradient(135deg, var(--luxury-gold, #D4AF37), var(--luxury-gold-dark, #B8941F));
  border-radius: 14px;
  flex-shrink: 0;
}

.learn-module__title {
  font-family: 'Playfair Display', serif;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--pearl-white, #F8F9FA);
  margin: 0;
}

.learn-module__lessons {
  list-style: none;
  margin: 0;
  padding: 0.5rem 0;
}

.learn-module__lessons li a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1.75rem;
  color: var(--platinum, #E5E4E2);
  text-decoration: none;
  transition: all 0.25s ease;
  border-left: 3px solid transparent;
}

.learn-module__lessons li a::before {
  content: '→';
  color: var(--luxury-gold, #D4AF37);
  opacity: 0;
  transform: translateX(-8px);
  transition: all 0.25s ease;
}

.learn-module__lessons li a:hover {
  background: rgba(212, 175, 55, 0.06);
  color: var(--pearl-white, #F8F9FA);
  border-left-color: var(--luxury-gold, #D4AF37);
  padding-left: 2rem;
}

.learn-module__lessons li a:hover::before {
  opacity: 1;
  transform: translateX(0);
}

.learn-module__empty {
  padding: 1rem 1.75rem;
  color: rgba(229, 228, 226, 0.5);
  font-style: italic;
  font-size: 0.95rem;
}

/* Lesson detail (more.php) */
.lesson-content {
  max-width: 820px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.lesson-content h1 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #fff, var(--luxury-gold, #D4AF37));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.lesson-section-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: 50px;
  background: rgba(212, 175, 55, 0.12);
  border: 1px solid rgba(212, 175, 55, 0.3);
  color: var(--luxury-gold, #D4AF37);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.lesson-body {
  color: var(--platinum, #E5E4E2);
  line-height: 1.85;
  font-size: 1.05rem;
}

.lesson-body h2, .lesson-body h3, .lesson-body h4 {
  font-family: 'Playfair Display', serif;
  color: var(--pearl-white, #F8F9FA);
  margin: 2rem 0 1rem;
}

.lesson-body p { margin-bottom: 1.25rem; }

.lesson-body ul, .lesson-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.lesson-body li { margin-bottom: 0.5rem; }

.lesson-body img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  margin: 1.5rem 0;
  border: 1px solid rgba(212, 175, 55, 0.2);
}

.lesson-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.lesson-body th, .lesson-body td {
  border: 1px solid rgba(212, 175, 55, 0.2);
  padding: 0.75rem 1rem;
  text-align: left;
}

.lesson-body th {
  background: rgba(212, 175, 55, 0.1);
  color: var(--luxury-gold, #D4AF37);
  font-weight: 600;
}

.lesson-body pre {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid rgba(212, 175, 55, 0.15);
  border-radius: 12px;
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-size: 0.9rem;
  line-height: 1.6;
}

.lesson-body code {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 0.9em;
}

.lesson-body :not(pre) > code {
  background: rgba(212, 175, 55, 0.12);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  color: var(--luxury-gold-light, #F4D03F);
}

.lesson-body blockquote {
  border-left: 4px solid var(--luxury-gold, #D4AF37);
  padding: 0.75rem 1.25rem;
  margin: 1.5rem 0;
  background: rgba(212, 175, 55, 0.05);
  font-style: italic;
}

.lesson-body a {
  color: var(--luxury-gold, #D4AF37);
  text-decoration: underline;
  text-underline-offset: 3px;
}

[dir="rtl"] .learn-module__lessons li a {
  border-left: none;
  border-right: 3px solid transparent;
}

[dir="rtl"] .learn-module__lessons li a:hover {
  border-right-color: var(--luxury-gold, #D4AF37);
  padding-left: 1.75rem;
  padding-right: 2rem;
}

[dir="rtl"] .learn-module__lessons li a::before {
  content: '←';
}

[dir="rtl"] .learn-back-btn:hover {
  transform: translateX(3px);
}

@media (max-width: 768px) {
  .learn-nav__inner {
    padding: 0.75rem 1rem;
  }
  .learn-back-btn span.hide-mobile {
    display: none;
  }
}

/* ===== Rich lesson document blocks (inside .lesson-body) ===== */
.lesson-body .wrap {
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 0 4rem;
}

.lesson-body header.hero {
  padding: 2rem 0 2.5rem;
  text-align: left;
}

.lesson-body .kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--luxury-gold-light, #F4D03F);
  border: 1px solid rgba(212, 175, 55, 0.35);
  padding: 6px 14px;
  border-radius: 100px;
  background: rgba(212, 175, 55, 0.08);
}

.lesson-body .kicker span.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--emerald, #50C878);
  display: inline-block;
}

.lesson-body h1.title {
  font-family: 'Playfair Display', serif;
  font-weight: 800;
  font-size: clamp(34px, 5.5vw, 58px);
  line-height: 1.08;
  margin: 22px 0 10px;
  background: linear-gradient(135deg, #fff 0%, var(--luxury-gold, #D4AF37) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.01em;
}

.lesson-body .subtitle {
  font-family: 'Playfair Display', serif;
  font-style: italic;
  font-weight: 600;
  font-size: clamp(18px, 2.4vw, 24px);
  color: var(--luxury-gold-light, #F4D03F);
  margin: 0 0 26px;
}

.lesson-body .hero-desc {
  max-width: 640px;
  color: var(--platinum, #E5E4E2);
  font-size: 16.5px;
}

.lesson-body .hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.lesson-body .hero-meta .chip {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 12.5px;
  color: var(--platinum, #E5E4E2);
  border: 1px solid rgba(212, 175, 55, 0.2);
  padding: 7px 12px;
  border-radius: 8px;
  background: rgba(212, 175, 55, 0.06);
}

.lesson-body nav.toc {
  margin: 10px 0 40px;
}

.lesson-body nav.toc .toc-inner {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.03) 0%, rgba(212, 175, 55, 0.05) 100%);
  border: 1px solid rgba(212, 175, 55, 0.2);
  border-radius: 16px;
  padding: 22px 26px;
  backdrop-filter: blur(6px);
}

.lesson-body nav.toc h2 {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--luxury-gold, #D4AF37);
  margin: 0 0 16px;
}

.lesson-body .toc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 8px 20px;
}

.lesson-body .toc-grid a {
  color: var(--platinum, #E5E4E2);
  text-decoration: none;
  font-size: 14.5px;
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 6px 4px;
  border-radius: 6px;
  transition: color 0.25s ease, background 0.25s ease;
}

.lesson-body .toc-grid a:hover {
  color: var(--luxury-gold-light, #F4D03F);
  background: rgba(212, 175, 55, 0.06);
}

.lesson-body .toc-grid a .n {
  font-family: 'Fira Code', 'Consolas', monospace;
  color: var(--luxury-gold, #D4AF37);
  font-size: 12.5px;
  min-width: 20px;
}

.lesson-body section.lesson {
  padding: 54px 0 10px;
  border-top: 1px solid rgba(212, 175, 55, 0.12);
  scroll-margin-top: 100px;
}

.lesson-body .eyebrow {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--luxury-gold, #D4AF37);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.lesson-body .eyebrow .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: rgba(212, 175, 55, 0.14);
  border: 1px solid rgba(212, 175, 55, 0.4);
  color: var(--luxury-gold-light, #F4D03F);
  font-weight: 700;
}

.lesson-body h2.h {
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 32px);
  color: var(--pearl-white, #F8F9FA);
  margin: 0 0 18px;
}

.lesson-body h3.h3 {
  font-family: 'Playfair Display', serif;
  font-weight: 600;
  font-style: italic;
  color: var(--luxury-gold-light, #F4D03F);
  font-size: 19px;
  margin: 28px 0 10px;
}

.lesson-body section.lesson > p,
.lesson-body section.lesson > ul,
.lesson-body section.lesson > ol {
  color: var(--platinum, #E5E4E2);
  font-size: 16px;
}

.lesson-body section.lesson strong {
  color: var(--pearl-white, #F8F9FA);
}

.lesson-body .card {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.04) 0%, rgba(212, 175, 55, 0.06) 100%);
  color: var(--platinum, #E5E4E2);
  border-radius: 14px;
  padding: 22px 26px;
  margin: 18px 0;
  box-shadow: 0 14px 30px -14px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(212, 175, 55, 0.22);
}

.lesson-body .card.eq {
  background-image: repeating-linear-gradient(rgba(212, 175, 55, 0.08) 0 1px, transparent 1px 34px);
}

.lesson-body .card p,
.lesson-body .card li {
  color: var(--platinum, #E5E4E2);
}

.lesson-body .card strong {
  color: var(--pearl-white, #F8F9FA);
}

.lesson-body .card-label {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ruby, #E0115F);
  margin-bottom: 8px;
  font-weight: 700;
}

.lesson-body .ai-box {
  border-left: 3px solid var(--sapphire, #0F52BA);
  background: rgba(15, 82, 186, 0.1);
  border-radius: 0 12px 12px 0;
  padding: 16px 20px;
  margin: 18px 0;
}

.lesson-body .ai-box .card-label {
  color: var(--sapphire, #0F52BA);
}

.lesson-body .ai-box p {
  color: var(--platinum, #E5E4E2);
}

.lesson-body .example-box {
  border-left: 3px solid var(--emerald, #50C878);
  background: rgba(80, 200, 120, 0.08);
  border-radius: 0 12px 12px 0;
  padding: 16px 20px;
  margin: 18px 0;
}

.lesson-body .example-box .card-label {
  color: var(--emerald, #50C878);
}

.lesson-body .example-box p {
  color: var(--platinum, #E5E4E2);
}

.lesson-body figure {
  margin: 26px 0;
  text-align: center;
}

.lesson-body figure svg {
  max-width: 100%;
  height: auto;
}

.lesson-body figcaption {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 12px;
  color: var(--silver, #C0C0C0);
  margin-top: 10px;
  letter-spacing: 0.03em;
}

.lesson-body table.plain {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14.5px;
}

.lesson-body table.plain th,
.lesson-body table.plain td {
  padding: 9px 12px;
  border-bottom: 1px solid rgba(212, 175, 55, 0.2);
  text-align: left;
}

.lesson-body table.plain th {
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--luxury-gold, #D4AF37);
  background: rgba(212, 175, 55, 0.08);
}

.lesson-body .rule-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 14px 0;
}

.lesson-body .rule {
  background: rgba(212, 175, 55, 0.06);
  border: 1px solid rgba(212, 175, 55, 0.2);
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 14.5px;
  color: var(--platinum, #E5E4E2);
}

.lesson-body footer {
  text-align: center;
  padding: 60px 0 30px;
  color: var(--silver, #C0C0C0);
  font-family: 'Fira Code', 'Consolas', monospace;
  font-size: 12.5px;
  border-top: 1px solid rgba(212, 175, 55, 0.1);
}

.lesson-body ::selection {
  background: var(--luxury-gold, #D4AF37);
  color: var(--deep-navy, #0A0E27);
}

[dir="rtl"] .lesson-body .ai-box,
[dir="rtl"] .lesson-body .example-box {
  border-left: none;
  border-right: 3px solid;
  border-radius: 12px 0 0 12px;
}

[dir="rtl"] .lesson-body .ai-box {
  border-right-color: var(--sapphire, #0F52BA);
}

[dir="rtl"] .lesson-body .example-box {
  border-right-color: var(--emerald, #50C878);
}

@media (max-width: 640px) {
  .lesson-body .rule-grid {
    grid-template-columns: 1fr;
  }
}

/* —— Mailing list popup —— */
.mail-list-overlay {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem;
  background: rgba(5, 8, 20, 0.72);
  backdrop-filter: blur(8px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.28s ease, visibility 0.28s ease;
}

.mail-list-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.mail-list-overlay.is-mandatory {
  background: rgba(3, 5, 14, 0.88);
}

.mail-list-modal {
  position: relative;
  width: min(420px, 100%);
  padding: 2rem 1.75rem 1.75rem;
  border-radius: 18px;
  border: 1px solid rgba(212, 175, 55, 0.35);
  background:
    linear-gradient(165deg, rgba(22, 28, 52, 0.98) 0%, rgba(10, 14, 39, 0.99) 100%);
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, 0.04) inset,
    0 24px 60px rgba(0, 0, 0, 0.55);
  transform: translateY(12px) scale(0.97);
  transition: transform 0.28s ease;
  color: var(--pearl-white, #F8F9FA);
}

.mail-list-overlay.is-open .mail-list-modal {
  transform: translateY(0) scale(1);
}

.mail-list-modal__glow {
  position: absolute;
  top: -40%;
  left: 20%;
  right: 20%;
  height: 120px;
  background: radial-gradient(ellipse, rgba(212, 175, 55, 0.22), transparent 70%);
  pointer-events: none;
}

.mail-list-modal__close {
  position: absolute;
  top: 0.65rem;
  right: 0.75rem;
  width: 2rem;
  height: 2rem;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  color: var(--silver, #C0C0C0);
  font-size: 1.35rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.mail-list-modal__close:hover {
  background: rgba(212, 175, 55, 0.2);
  color: var(--luxury-gold, #D4AF37);
}

[dir="rtl"] .mail-list-modal__close {
  right: auto;
  left: 0.75rem;
}

.mail-list-modal__title {
  font-family: 'Playfair Display', serif;
  font-size: 1.55rem;
  font-weight: 700;
  margin: 0 0 0.55rem;
  background: linear-gradient(135deg, #fff 0%, var(--luxury-gold, #D4AF37) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.mail-list-modal__text {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--platinum, #E5E4E2);
  opacity: 0.9;
}

.mail-list-modal__note {
  margin: 0 0 1rem;
  font-size: 0.82rem;
  color: var(--luxury-gold, #D4AF37);
  opacity: 0.95;
}

.mail-list-form__label {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.mail-list-form__input {
  width: 100%;
  box-sizing: border-box;
  padding: 0.85rem 1rem;
  margin-bottom: 0.65rem;
  border-radius: 10px;
  border: 1px solid rgba(212, 175, 55, 0.28);
  background: rgba(255, 255, 255, 0.04);
  color: #fff;
  font-size: 1rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.mail-list-form__input::placeholder {
  color: rgba(192, 192, 192, 0.55);
}

.mail-list-form__input:focus {
  border-color: var(--luxury-gold, #D4AF37);
  box-shadow: 0 0 0 3px rgba(212, 175, 55, 0.15);
}

.mail-list-form__msg {
  margin: 0 0 0.65rem;
  font-size: 0.85rem;
  min-height: 1.2em;
}

.mail-list-form__msg--error {
  color: #ff8a8a;
}

.mail-list-form__msg--ok {
  color: #7dcea0;
}

.mail-list-form__btn {
  width: 100%;
  padding: 0.85rem 1rem;
  border: none;
  border-radius: 50px;
  background: linear-gradient(135deg, #c9a227 0%, #D4AF37 50%, #e8d48b 100%);
  color: #0A0E27;
  font-weight: 700;
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform 0.2s, filter 0.2s, opacity 0.2s;
}

.mail-list-form__btn:hover:not(:disabled) {
  transform: translateY(-1px);
  filter: brightness(1.05);
}

.mail-list-form__btn:disabled {
  opacity: 0.7;
  cursor: wait;
}