:root {
  --bg: #686446;
  --ink: #ffffff;
  --panel: #35393d;
  --panel-soft: #434847;
  --lime: #83d10b;
  --lime-dark: #4f9f00;
  --gold: #d6bc6c;
  --teal: #178a86;
  --muted: #d9ded0;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Roboto", Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 82px;
  padding: 22px clamp(18px, 4vw, 64px);
  background: rgba(53, 57, 61, 0.94);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(12px);
}

.brand img {
  width: min(381px, 42vw);
  height: auto;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-left: auto;
  font-size: 14px;
  font-weight: 700;
}

.main-nav a,
.header-actions a {
  text-decoration: none;
}

.main-nav a {
  color: rgba(255, 255, 255, 0.84);
}

.main-nav a:hover {
  color: var(--lime);
}

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

.link-button,
.primary-action,
.secondary-action,
.wide-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 7px;
  font-weight: 900;
  text-decoration: none;
}

.link-button,
.primary-action,
.wide-action {
  color: #fff;
  background: linear-gradient(180deg, var(--lime), var(--lime-dark));
  box-shadow: 0 12px 28px rgba(52, 95, 0, 0.3);
}

.link-button.ghost,
.secondary-action {
  color: #fff;
  background: rgba(255, 255, 255, 0.11);
  border: 1px solid rgba(255, 255, 255, 0.22);
  box-shadow: none;
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  border: 0;
  border-radius: 7px;
  background: rgba(255, 255, 255, 0.12);
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  background: #fff;
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(300px, 0.86fr) minmax(360px, 1.14fr);
  align-items: center;
  min-height: calc(100vh - 82px);
  padding: clamp(44px, 7vw, 92px) clamp(20px, 5vw, 78px) 84px;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 150px;
  background: linear-gradient(0deg, rgba(53, 57, 61, 0.48), transparent);
  pointer-events: none;
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 700px;
  animation: heroCopyDrop 0.92s cubic-bezier(0.18, 0.9, 0.24, 1.18) both;
}

.eyebrow,
.section-kicker {
  margin: 0 0 10px;
  color: var(--gold);
  font-size: 14px;
  font-weight: 900;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 20px;
  font-size: clamp(48px, 7vw, 96px);
  line-height: 0.92;
  font-weight: 900;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(30px, 4vw, 54px);
  line-height: 1.02;
  font-weight: 900;
}

h3 {
  margin-bottom: 8px;
  font-size: 21px;
}

.hero-text,
.section-copy p,
.showcase-copy p,
.teacher-band p,
.steps p,
.feature-grid p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.hero-actions,
.teacher-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.hero-stage {
  position: relative;
  min-height: 560px;
  isolation: isolate;
}

.hero-background {
  position: absolute;
  right: -5%;
  bottom: 18px;
  width: min(820px, 112%);
  border-radius: 8px;
  object-fit: cover;
  box-shadow: var(--shadow);
  filter: saturate(1.05) contrast(1.02);
}

.character-card {
  position: absolute;
  z-index: 2;
  width: min(260px, 34%);
  border-radius: 8px;
  background: #f7f4e8;
  box-shadow: 0 24px 44px rgba(0, 0, 0, 0.38);
  animation: characterFloat 5.5s ease-in-out infinite;
}

.character-alex {
  left: 2%;
  bottom: 6%;
}

.character-valentina {
  right: 4%;
  top: 7%;
  animation-delay: 1.4s;
}

.hero-panel {
  position: absolute;
  z-index: 3;
  width: min(230px, 46%);
  padding: 16px 18px;
  border-radius: 8px;
  background: rgba(53, 57, 61, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.16);
  box-shadow: var(--shadow);
}

.hero-panel span {
  display: block;
  margin-bottom: 8px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 13px;
  font-weight: 700;
}

.hero-panel strong {
  display: inline-block;
  color: var(--lime);
  font-size: 22px;
}

.panel-class {
  left: 7%;
  top: 12%;
}

.panel-chapters {
  right: 2%;
  bottom: 12%;
}

.intro-band,
.teacher-band,
.teacher-tools,
.value-section,
.steps-section {
  padding: clamp(54px, 8vw, 98px) clamp(20px, 5vw, 78px);
}

.intro-band,
.steps-section {
  background: #35393d;
}

.teacher-tools {
  background: linear-gradient(180deg, rgba(67, 72, 71, 0.82), rgba(53, 57, 61, 0.96)), var(--panel);
}

.teacher-band {
  display: grid;
  grid-template-columns: minmax(300px, 0.9fr) minmax(280px, 0.62fr);
  align-items: center;
  gap: 28px;
}

.teacher-image {
  margin: 0;
  padding: clamp(12px, 2vw, 20px);
  border-radius: 8px;
  background: #1e2022;
  box-shadow: var(--shadow);
}

.teacher-image img {
  width: 100%;
  max-height: 520px;
  border-radius: 7px;
  object-fit: cover;
  object-position: center top;
}

.section-copy {
  max-width: 850px;
}

.feature-grid,
.teacher-tool-grid,
.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 34px;
}

.feature-grid article,
.teacher-tool-grid article,
.steps article {
  min-height: 220px;
  padding: 26px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.feature-grid span,
.teacher-tool-grid strong,
.steps strong {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 42px;
  padding: 0 14px;
  margin-bottom: 24px;
  border-radius: 999px;
  background: var(--teal);
  color: #fff;
  font-weight: 900;
}

.feature-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  margin: 0 0 20px;
  border-radius: 7px;
  object-fit: cover;
  background: #24272a;
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.22);
}

.showcase {
  display: grid;
  grid-template-columns: minmax(320px, 1fr) minmax(300px, 0.86fr);
  gap: clamp(28px, 5vw, 70px);
  align-items: center;
  padding: clamp(54px, 8vw, 98px) clamp(20px, 5vw, 78px);
}

.showcase-visual {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  padding: clamp(18px, 3vw, 34px);
  border-radius: 8px;
  background: #1e2022;
  box-shadow: var(--shadow);
}

.showcase-visual img {
  width: 100%;
  height: 100%;
  min-height: 360px;
  border-radius: 7px;
  object-fit: cover;
}

.check-list {
  display: grid;
  gap: 12px;
  padding: 0;
  margin: 28px 0 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 32px;
  color: #fff;
  font-weight: 700;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: inset 0 0 0 5px rgba(255, 255, 255, 0.18);
}

.wide-action {
  width: min(100%, 420px);
  margin-top: 28px;
}

.value-section {
  display: grid;
  grid-template-columns: minmax(300px, 0.86fr) minmax(320px, 1fr);
  gap: clamp(28px, 5vw, 70px);
  align-items: center;
  background: #35393d;
  overflow: hidden;
}

.value-copy {
  max-width: 760px;
}

.value-copy p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.value-carousel {
  display: grid;
  gap: 18px;
  justify-items: center;
  min-height: 520px;
  perspective: 1200px;
}

.carousel-stage {
  position: relative;
  width: min(100%, 520px);
  min-height: 500px;
  transform-style: preserve-3d;
}

.carousel-card {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-rows: 1fr auto;
  margin: 0;
  overflow: hidden;
  border-radius: 8px;
  background: #1e2022;
  border: 1px solid rgba(255, 255, 255, 0.14);
  box-shadow: var(--shadow);
  opacity: 0.42;
  transform: rotateY(var(--card-rotation)) translateZ(90px) scale(0.86);
  transition: transform 0.72s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.72s ease;
  backface-visibility: hidden;
}

.carousel-card:nth-child(1) {
  --card-rotation: 0deg;
}

.carousel-card:nth-child(2) {
  --card-rotation: 180deg;
}

.carousel-stage[data-active="1"] .carousel-card:nth-child(1) {
  --card-rotation: -180deg;
}

.carousel-stage[data-active="1"] .carousel-card:nth-child(2) {
  --card-rotation: 0deg;
}

.carousel-card.is-active {
  z-index: 2;
  opacity: 1;
  transform: rotateY(var(--card-rotation)) translateZ(130px) scale(1);
}

.carousel-card img {
  width: 100%;
  height: 100%;
  min-height: 440px;
  object-fit: cover;
  object-position: center top;
}

.carousel-card figcaption {
  padding: 16px 18px;
  color: var(--lime);
  font-size: 22px;
  font-weight: 900;
  text-align: center;
}

.carousel-controls {
  display: flex;
  gap: 10px;
  margin-top: 18px;
}

.carousel-controls button {
  width: 44px;
  height: 12px;
  min-height: 12px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.3);
  box-shadow: none;
}

.carousel-controls button.is-active {
  background: var(--lime);
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 28px;
  align-items: center;
  padding: 34px clamp(20px, 5vw, 78px);
  background: #1f2225;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
}

.site-footer img {
  width: 96px;
  margin-bottom: 8px;
}

.site-footer p,
.site-footer address {
  margin: 0;
  color: rgba(255, 255, 255, 0.78);
  font-style: normal;
  line-height: 1.55;
}

.site-footer a {
  color: var(--lime);
  font-weight: 900;
  text-decoration: none;
}

.credits {
  text-align: right;
}

@keyframes heroCopyDrop {
  0% {
    opacity: 0;
    transform: translateY(-120px) scale(0.96);
  }
  62% {
    opacity: 1;
    transform: translateY(18px) scale(1.02);
  }
  78% {
    transform: translateY(-10px) scale(0.995);
  }
  90% {
    transform: translateY(5px) scale(1.005);
  }
  100% {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes characterFloat {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-14px);
  }
}

@media (max-width: 980px) {
  .site-header {
    flex-wrap: wrap;
  }

  .menu-toggle {
    display: block;
  }

  .main-nav,
  .header-actions {
    display: none;
    width: 100%;
  }

  .site-header.is-open .main-nav,
  .site-header.is-open .header-actions {
    display: flex;
  }

  .main-nav,
  .header-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero,
  .value-section,
  .showcase {
    grid-template-columns: 1fr;
  }

  .hero-stage {
    min-height: 430px;
  }

  .feature-grid,
  .teacher-tool-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .teacher-band,
  .site-footer {
    display: grid;
    grid-template-columns: 1fr;
  }

  .credits {
    text-align: left;
  }
}

@media (max-width: 620px) {
  .site-header {
    min-height: 72px;
  }

  .brand img {
    width: 96px;
  }

  .hero {
    min-height: auto;
    padding-top: 42px;
  }

  .hero-stage {
    min-height: 390px;
  }

  .hero-background {
    right: -70px;
    width: 760px;
    max-width: none;
  }

  .character-card {
    width: 42%;
  }

  .hero-panel {
    position: relative;
    display: inline-block;
    width: calc(50% - 8px);
    margin-top: 294px;
  }

  .panel-class,
  .panel-chapters {
    left: auto;
    right: auto;
    top: auto;
    bottom: auto;
  }

  .hero-panel strong {
    font-size: 17px;
  }

  .showcase-visual {
    grid-template-columns: 1fr;
  }

  .value-carousel {
    min-height: 430px;
  }

  .carousel-stage {
    min-height: 410px;
  }

  .carousel-card img {
    min-height: 350px;
  }
}