/* ============================================
   LessonHub Landing Page Styles
   Colors: Navy #212943, Sage #9DBDB8, Dark Sage #667C78
   Font: Rubik
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --navy: #212943;
  --navy-light: #2d3a5c;
  --navy-dark: #181d30;
  --sage: #9DBDB8;
  --sage-light: #c2dad6;
  --sage-dark: #667C78;
  --white: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-900: #111827;
  --font-sans: 'Rubik', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.05);
  --shadow-xl: 0 20px 50px -5px rgba(0,0,0,0.15);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  color: var(--gray-700);
  background: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

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

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--navy);
  text-align: center;
  margin-bottom: 12px;
  line-height: 1.2;
}

.section-title--left { text-align: left; }

.section-subtitle {
  font-size: 1.125rem;
  color: var(--gray-500);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 56px;
  font-weight: 400;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-weight: 600;
  border: 2px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  text-decoration: none;
}

.btn--sm { padding: 8px 20px; font-size: 0.875rem; }
.btn--lg { padding: 14px 32px; font-size: 1rem; }
.btn--full { width: 100%; }

.btn--primary {
  background: var(--sage);
  color: var(--navy);
  border-color: var(--sage);
}
.btn--primary:hover {
  background: var(--sage-dark);
  border-color: var(--sage-dark);
  color: var(--white);
}

.btn--accent {
  background: var(--sage);
  color: var(--navy);
  border-color: var(--sage);
}
.btn--accent:hover {
  background: var(--sage-dark);
  border-color: var(--sage-dark);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn--outline {
  background: transparent;
  color: var(--white);
  border-color: rgba(255,255,255,0.4);
}
.btn--outline:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.7);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: var(--transition);
}

.nav--solid {
  background: rgba(33, 41, 67, 0.97);
  backdrop-filter: blur(12px);
  padding: 10px 0;
  box-shadow: var(--shadow);
}

.nav__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav__icon { height: 32px; width: auto; }
.nav__wordmark { height: 20px; width: auto; filter: brightness(0) invert(1); }

.nav__links {
  display: flex;
  gap: 32px;
}

.nav__links a {
  color: rgba(255,255,255,0.75);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav__links a:hover { color: var(--white); }

/* --- Nav actions --- */
.nav__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav__login {
  border-color: rgba(255,255,255,0.35);
  color: var(--white);
}
.nav__login:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.6);
}

/* --- Language Switcher --- */
.lang-switcher {
  position: relative;
}

.lang-switcher__btn {
  display: flex;
  align-items: center;
  gap: 4px;
  background: none;
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: var(--radius-sm);
  color: rgba(255,255,255,0.8);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 6px 10px;
  cursor: pointer;
  transition: var(--transition);
  letter-spacing: 0.03em;
}
.lang-switcher__btn:hover {
  border-color: rgba(255,255,255,0.5);
  color: var(--white);
}

.lang-switcher__menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  min-width: 140px;
  padding: 4px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: var(--transition);
  z-index: 110;
}

.lang-switcher__menu.open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-switcher__option {
  display: block;
  width: 100%;
  padding: 8px 12px;
  background: none;
  border: none;
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--gray-700);
  text-align: left;
  cursor: pointer;
  transition: var(--transition);
}
.lang-switcher__option:hover {
  background: var(--gray-50);
  color: var(--navy);
}
.lang-switcher__option.active {
  background: var(--sage);
  color: var(--navy);
  font-weight: 600;
}

/* --- Burger Menu --- */
.nav__burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav__burger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: var(--transition);
}

.nav__burger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav__burger.active span:nth-child(2) {
  opacity: 0;
}
.nav__burger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Mobile Menu --- */
.nav__mobile {
  display: none;
  background: rgba(33, 41, 67, 0.98);
  backdrop-filter: blur(12px);
  padding: 16px 24px 24px;
  border-top: 1px solid rgba(255,255,255,0.08);
}

.nav__mobile.open {
  display: block;
}

.nav__mobile ul {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.nav__mobile a {
  display: block;
  padding: 14px 0;
  color: rgba(255,255,255,0.8);
  font-size: 1rem;
  font-weight: 500;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: var(--transition);
}
.nav__mobile a:hover {
  color: var(--sage);
}

.nav__mobile li:last-child a {
  border-bottom: none;
}

@media (max-width: 768px) {
  .nav__links { display: none; }
  .nav__login { display: none; }
  .nav__burger { display: flex; }
  .btn--sm.nav__actions > .btn--primary { display: none; }
}

@media (max-width: 560px) {
  .nav__actions .btn--primary { display: none; }
}

/* --- Hero --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 50%, var(--navy) 100%);
  padding: 120px 24px 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 200%;
  background: radial-gradient(ellipse at center, rgba(157, 189, 184, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero__content {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero__title {
  font-size: clamp(2.5rem, 5.5vw, 4rem);
  font-weight: 800;
  color: var(--white);
  line-height: 1.1;
  margin-bottom: 24px;
}

.hero__title .word {
  display: inline-block;
  opacity: 0;
  transform: translateY(30px);
  margin-right: 0.3em;
}

.hero__accent {
  color: var(--sage);
}

.hero__subtitle {
  font-size: 1.2rem;
  color: rgba(255,255,255,0.7);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 520px;
  font-weight: 300;
}

.hero__cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  opacity: 0;
  transform: translateY(20px);
}

.hero__visual {
  position: relative;
  height: 400px;
}

.hero__card {
  position: absolute;
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: var(--radius);
  padding: 20px 28px;
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  font-weight: 500;
  font-size: 0.95rem;
  opacity: 0;
  box-shadow: 0 8px 32px rgba(0,0,0,0.2);
}

.hero__card-icon { font-size: 1.5rem; }

.hero__card--1 { top: 15%; right: 10%; }
.hero__card--2 { top: 45%; left: 5%; }
.hero__card--3 { bottom: 10%; right: 20%; }

@media (max-width: 900px) {
  .hero__content { grid-template-columns: 1fr; text-align: center; }
  .hero__subtitle { margin-left: auto; margin-right: auto; }
  .hero__cta { justify-content: center; }
  .hero__visual { display: none; }
}

/* --- Features --- */
.features {
  padding: 120px 0;
  background: var(--white);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(40px);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--sage);
}

.feature-card__icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--sage);
  color: var(--navy);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--gray-500);
  line-height: 1.6;
}

@media (max-width: 900px) {
  .features__grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 560px) {
  .features__grid { grid-template-columns: 1fr; }
}

/* --- How It Works --- */
.how-it-works {
  padding: 120px 0;
  background: var(--gray-50);
}

.steps {
  position: relative;
  max-width: 640px;
  margin: 0 auto;
}

.steps__line {
  position: absolute;
  left: 24px;
  top: 28px;
  bottom: 28px;
  width: 4px;
}

.steps__line-svg {
  width: 100%;
  height: 100%;
}

.steps__line-path {
  stroke-dashoffset: 800;
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  padding: 24px 0;
  position: relative;
  opacity: 0;
  transform: translateX(-30px);
}

.step__number {
  width: 52px;
  height: 52px;
  min-width: 52px;
  border-radius: 50%;
  background: var(--navy);
  color: var(--sage);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
  position: relative;
  z-index: 2;
}

.step__content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 4px;
}

.step__content p {
  color: var(--gray-500);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* --- Game Showcase --- */
.games {
  padding: 120px 0;
  background: var(--white);
}

.games__grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 16px;
}

.game-card {
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  padding: 20px 8px;
  text-align: center;
  transition: var(--transition);
  cursor: default;
}

.game-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: var(--sage);
  background: var(--white);
}

.game-card__icon {
  font-size: 1.75rem;
  margin-bottom: 8px;
}

.game-card span {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--navy);
}

@media (max-width: 900px) {
  .games__grid { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 560px) {
  .games__grid { grid-template-columns: repeat(3, 1fr); }
}

/* --- Audience (For Whom) --- */
.audience {
  padding: 120px 0;
  background: var(--gray-50);
}

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

.audience-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(30px);
}

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

.audience-card--accent {
  border-color: var(--sage);
  background: linear-gradient(135deg, rgba(157, 189, 184, 0.08) 0%, var(--white) 100%);
  position: relative;
}

.audience-card--accent::before {
  content: 'Popular';
  position: absolute;
  top: 16px;
  right: 16px;
  background: var(--sage);
  color: var(--navy);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.audience-card__icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  background: var(--gray-50);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--navy);
}

.audience-card--accent .audience-card__icon {
  background: var(--sage);
}

.audience-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 10px;
}

.audience-card > p {
  font-size: 0.9rem;
  color: var(--gray-500);
  line-height: 1.65;
  margin-bottom: 20px;
}

.audience-card__list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.audience-card__list li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--gray-600);
  font-weight: 500;
}

.audience-card__list li::before {
  content: '';
  width: 16px;
  height: 16px;
  min-width: 16px;
  border-radius: 50%;
  background: var(--sage);
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='10' viewBox='0 0 24 24' fill='none' stroke='%23212943' stroke-width='3' stroke-linecap='round' stroke-linejoin='round' xmlns='http://www.w3.org/2000/svg'%3E%3Cpolyline points='20 6 9 17 4 12'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  background-size: 9px;
}

@media (max-width: 900px) {
  .audience__grid { grid-template-columns: 1fr; max-width: 480px; margin: 0 auto; }
}

/* --- Stats --- */
.stats {
  padding: 80px 0;
  background: var(--navy);
}

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

.stat__number {
  display: block;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  color: var(--sage);
  line-height: 1;
  margin-bottom: 8px;
}

.stat__label {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.6);
  font-weight: 400;
}

@media (max-width: 768px) {
  .stats__grid { grid-template-columns: repeat(2, 1fr); gap: 40px; }
}

/* --- Application Form --- */
.apply {
  padding: 120px 0;
  background: var(--gray-50);
}

.apply__wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.apply__info p {
  color: var(--gray-500);
  font-size: 1.05rem;
  margin-bottom: 24px;
  line-height: 1.7;
}

.apply__benefits {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.apply__benefits li {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--gray-600);
  font-size: 0.95rem;
}

.apply__benefits li::before {
  content: '';
  width: 20px;
  height: 20px;
  min-width: 20px;
  border-radius: 50%;
  background: var(--sage);
  display: flex;
  align-items: center;
  justify-content: center;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23212943' stroke-width='3' stroke-linecap='round' stroke-linejoin='round' xmlns='http://www.w3.org/2000/svg'%3E%3Cpolyline points='20 6 9 17 4 12'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  background-size: 11px;
}

.apply__form {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: 20px;
  opacity: 0;
  transform: translateY(15px);
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: 6px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  color: var(--gray-900);
  background: var(--white);
  transition: var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--sage);
  box-shadow: 0 0 0 3px rgba(157, 189, 184, 0.2);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--gray-400);
}

.form-group textarea { resize: vertical; }

.form-group input.error,
.form-group select.error {
  border-color: #ef4444;
}

.apply__form-note {
  text-align: center;
  font-size: 0.8rem;
  color: var(--gray-400);
  margin-top: 12px;
}

.form-success {
  text-align: center;
  padding: 40px 20px;
}

.form-success h3 {
  font-size: 1.25rem;
  color: var(--navy);
  margin-bottom: 8px;
}

.form-success p {
  color: var(--gray-500);
  font-size: 0.95rem;
}

@media (max-width: 900px) {
  .apply__wrapper { grid-template-columns: 1fr; gap: 40px; }
}

/* --- Footer --- */
.footer {
  background: var(--navy-dark);
  padding: 64px 0 32px;
  color: rgba(255,255,255,0.5);
}

.footer__inner {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer__logo img:last-child {
  filter: brightness(0) invert(1);
  opacity: 0.8;
}

.footer__tagline {
  font-size: 0.9rem;
  max-width: 280px;
}

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

.footer__col h4 {
  color: rgba(255,255,255,0.85);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
}

.footer__col ul { display: flex; flex-direction: column; gap: 10px; }

.footer__col a {
  font-size: 0.9rem;
  transition: var(--transition);
}
.footer__col a:hover { color: var(--sage); }

.footer__bottom {
  padding-top: 24px;
  text-align: center;
  font-size: 0.8rem;
}

@media (max-width: 768px) {
  .footer__inner { grid-template-columns: 1fr; }
  .footer__links { grid-template-columns: repeat(2, 1fr); }
}

/* --- Toast notification --- */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--navy);
  color: var(--white);
  padding: 14px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: var(--shadow-xl);
  z-index: 200;
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: var(--transition);
}

.toast--visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.toast--error {
  background: #ef4444;
}