/* Landing page — Bureau Gorbunov style */

:root {
  --book-bg: #d23c0b;
  --text-color: #000;
  --key-color: #fc5620;
  --hover-color: #fcc033;
  --gray-bg: #f5f5f5;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 18px;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  line-height: 1.5;
  color: var(--text-color);
  background: #fff;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ========================================
   Hero Section
   ======================================== */

.hero {
  background: var(--book-bg);
  color: #fff;
  padding: 60px 40px 80px;
  /* min-height: 100vh; */
  display: flex;
  align-items: flex-start;
}

@media (max-width: 768px) {
  .hero {
    min-height: auto;
  }
}

.hero-inner {
  max-width: 1000px;
  margin: 0 auto;
  width: 100%;
}

/* Hero Header — title above columns */
.hero-header {
  margin-bottom: 48px;
}

@media (max-width: 768px) {
  .hero-header {
    text-align: center;
    margin-bottom: 32px;
  }
}

.hero-eyebrow {
  font-size: 1.125rem;
  font-weight: 400;
  margin: 0 0 8px;
  opacity: 0.8;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.1;
  margin: 0;
  letter-spacing: -0.02em;
}

@media (max-width: 600px) {
  .hero-title {
    font-size: 2rem;
  }
}

/* Hero Columns — cover and description side by side */
.hero-columns {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 40px;
  align-items: start;
}

@media (max-width: 768px) {
  .hero-columns {
    grid-template-columns: 1fr;
    gap: 32px;
    justify-items: center;
  }
}

/* Hero Book Cover */
.hero-cover {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Hero Description */
.hero-description {
  font-size: 1.25rem;
  line-height: 1.6;
  padding-top: 8px;
}

.hero-description p {
  margin: 0 0 1em;
}

.hero-description p:last-child {
  margin-bottom: 0;
}

@media (max-width: 768px) {
  .hero-description {
    text-align: center;
    padding-top: 0;
  }
}

/* 3D Animated Book */
.book-wrapper {
  perspective: 1000px;
  perspective-origin: 50% 50%;
}

.book {
  position: relative;
  width: 320px;
  aspect-ratio: 1 / 1.414;
  transform-style: preserve-3d;
  transform: rotateY(-25deg);
  transition: transform 0.5s cubic-bezier(0.23, 1, 0.32, 1);
}

@media (max-width: 600px) {
  .book {
    width: 200px;
  }
}

.book:hover {
  transform: rotateY(-15deg);
}

.book-face {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  box-shadow: 0 30px 60px -12px rgba(0, 0, 0, 0.4),
    0 18px 36px -18px rgba(0, 0, 0, 0.5), -5px 5px 20px rgba(0, 0, 0, 0.3);
  border-radius: 0 8px 8px 0;
  transform-style: preserve-3d;
  overflow: hidden;
}

.book-face img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 0 8px 8px 0;
}

.book-spine {
  position: absolute;
  left: 0;
  top: 0;
  width: 18px;
  height: 100%;
  background: linear-gradient(to right, #7a2106 0%, #9a2d08 100%);
  transform: rotateY(-90deg) translateX(-9px);
  transform-origin: left center;
  border-radius: 3px 0 0 3px;
}

.book-back {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: #a52b07;
  transform: translateZ(-18px);
  border-radius: 0 3px 3px 0;
}

/* Action Button */
.action-buttons {
  margin-top: 32px;
  text-align: center;
}

.action-button {
  display: inline-block;
  padding: 0 18px;
  font-size: 16px;
  line-height: 36px;
  font-weight: 400;
  color: #000;
  background: #fff;
  border-radius: 3px;
  transition: all 0.15s ease;
}

.action-button:hover {
  background: var(--hover-color);
  color: #000;
}

/* ========================================
   Content Sections
   ======================================== */

.section {
  padding: 80px 40px;
}

@media (max-width: 768px) {
  .section {
    padding: 60px 20px;
  }
}

.section--gray {
  background: var(--gray-bg);
}

.section-inner {
  max-width: 800px;
  margin: 0 auto;
}

.section-inner--wide {
  max-width: 1000px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin: 0 0 48px;
  text-align: center;
}

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

/* About Text */
.about-text p {
  font-size: 1.25rem;
  line-height: 1.7;
  color: #333;
  margin: 0 0 24px;
}

.about-text p:last-child {
  margin-bottom: 0;
}

/* Contents Grid */
.contents-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

@media (max-width: 900px) {
  .contents-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px 24px;
  }
}

@media (max-width: 500px) {
  .contents-grid {
    grid-template-columns: 1fr 1fr;
    gap: 24px 16px;
  }
}

.contents-item-emoji {
  font-size: 40px;
  line-height: 1;
  height: 50px;
  margin-bottom: 8px;
}

.contents-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 8px;
}

.contents-item ul {
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 0.9rem;
  color: #555;
  line-height: 1.5;
}

.contents-item li {
  padding: 2px 0;
}

.contents-item li.exercise {
  font-style: italic;
  color: #999;
}

/* Steps */
.steps {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.step {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.step-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background: var(--book-bg);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.25rem;
}

.step-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: 0 0 8px;
}

.step-content p {
  margin: 0;
  color: #555;
}

/* ========================================
   CTA Section
   ======================================== */

.cta {
  background: var(--book-bg);
  color: #fff;
  padding: 80px 40px;
  text-align: center;
}

@media (max-width: 768px) {
  .cta {
    padding: 60px 20px;
  }
}

.cta-title {
  font-size: 2rem;
  font-weight: 700;
  margin: 0 0 16px;
}

.cta-text {
  font-size: 1.25rem;
  margin: 0 0 40px;
  opacity: 0.9;
}

/* ========================================
   Footer
   ======================================== */

.footer {
  background: #1a1a1a;
  color: #666;
  padding: 40px 20px;
  text-align: center;
  font-size: 0.875rem;
}

.footer p {
  margin: 0;
}