:root {
    --bg: #0a0a0c;
    --page-bg: #121214;
    --text: #dcd3c2;
    --gold: #c5a059;
    --gold-dim: #8a7038;
    --border: #2a2a2e;
  }

  * { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

  html, body {
    overflow: hidden;
    height: 100vh;
    width: 100vw;
    touch-action: none;
  }

  body {
    background-color: var(--bg);
    color: var(--text);
    font-family: 'Inter', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 2500px;
    user-select: none;
    -webkit-user-select: none;
    position: relative;
  }

  body::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: radial-gradient(circle at center, transparent 0%, #050505 90%);
    pointer-events: none;
    z-index: 1;
  }

  .book-scene {
    position: relative;
    width: 90vw;
    max-width: 1100px;
    height: 85vh;
    max-height: 750px;
    transform-style: preserve-3d;
    z-index: 2;
  }

  .book {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
  }

  .page {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    transform-origin: left center;
    transform-style: preserve-3d;
    transition: transform 1.2s cubic-bezier(0.645, 0.045, 0.355, 1), z-index 0s 0.6s;
    cursor: grab;
  }

  .page.dragging {
    transition: none;
    cursor: grabbing;
  }

  .page.flipped {
    transform: rotateY(-180deg);
  }

  .page-face {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    background: var(--page-bg);
    border: 1px solid var(--border);
    box-shadow: 
      inset 15px 0 30px -10px rgba(0,0,0,0.8), 
      0 10px 30px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 4rem;
    text-align: center;
    overflow: hidden;
    transition: box-shadow 0.1s linear, border-radius 0.1s linear; 
  }

  .curl-shadow {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    opacity: 0;
    pointer-events: none;
    z-index: 2;
  }

  .page-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, #151515, #0d0d0d);
  }

  .page-num {
    font-family: 'Cormorant Garamond', serif;
    font-size: 1rem;
    color: var(--gold-dim);
    letter-spacing: 0.4em;
    position: absolute;
    top: 3rem;
    right: 3rem;
    z-index: 1;
  }

  .page-content {
    max-width: 800px;
    width: 100%;
    pointer-events: none;
    position: relative;
    z-index: 3;
  }

  .page-content .contact-form, 
  .page-content .btn,
  .page-content .skip-intro {
    pointer-events: auto;
  }

  h2 {
    font-family: 'Cormorant Garamond', serif;
    font-size: clamp(1.8rem, 4.5vw, 3.8rem);
    font-weight: 300;
    line-height: 1.2;
    color: #e8e0cf;
    margin-bottom: 2rem;
  }

  .highlight {
    color: var(--gold);
    font-style: italic;
    font-weight: 600;
  }

  .divider {
    width: 60px;
    height: 1px;
    background: var(--gold-dim);
    margin: 2rem auto;
  }

  .btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--text);
    text-decoration: none;
    border: 1px solid var(--gold-dim);
    padding: 1.2rem 3rem;
    margin-top: 2rem;
    transition: all 0.4s ease;
    background: transparent;
    cursor: pointer;
    display: inline-block;
  }

  .btn:hover {
    color: var(--bg);
    background: var(--gold);
    border-color: var(--gold);
  }

  .brand-logo {
    font-family: 'Cormorant Garamond', serif;
    font-size: 2.5rem;
    color: #e8e0cf;
    margin-bottom: 0.5rem;
  }

  .brand-trademark {
    font-size: 0.9rem;
    vertical-align: super;
    color: var(--gold);
    font-weight: 400;
    font-style: normal;
    margin-left: 0.2rem;
    letter-spacing: normal;
  }

  .brand-tagline {
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.3em;
    color: var(--gold-dim);
    margin-bottom: 2rem;
  }

  .contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 450px;
    margin: 0 auto;
    text-align: left;
  }

  .form-group input,
  .form-group textarea {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--border);
    color: var(--text);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    padding: 0.8rem 0.2rem;
    outline: none;
    transition: border-color 0.3s ease;
    resize: none;
  }

  .form-group input:focus,
  .form-group textarea:focus {
    border-bottom-color: var(--gold);
  }

  .form-group input::placeholder,
  .form-group textarea::placeholder {
    color: #555048;
  }

  /* Сноска ФЗ-152 */
  .fz-note {
    font-size: 0.7rem;
    color: #6a6258;
    text-align: center;
    margin-top: 1.5rem;
    line-height: 1.5;
  }

  .fz-note a {
    color: var(--gold-dim);
    text-decoration: underline;
    text-underline-offset: 2px;
  }

  .nav-controls {
    position: fixed;
    bottom: 3vh;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 2rem;
    z-index: 3;
  }

  .nav-btn {
    background: none;
    border: 1px solid var(--border);
    color: var(--text);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .nav-btn:hover:not(:disabled) {
    border-color: var(--gold);
    color: var(--gold);
  }

  .nav-btn:disabled {
    opacity: 0.2;
    cursor: not-allowed;
  }

  .nav-btn-home {
    width: auto;
    min-width: 50px;
    padding: 0 1.25rem;
    border-radius: 25px;
    font-family: 'Inter', sans-serif;
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
  }

  .skip-intro {
    margin-top: 2.5rem;
    text-align: center;
    font-size: 0.75rem;
  }

  .skip-intro a {
    color: #6a6258;
    text-decoration: none;
    letter-spacing: 0.08em;
    transition: color 0.3s ease;
    cursor: pointer;
  }

  .skip-intro a:hover {
    color: var(--gold);
  }

  .hp-field {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
  }

  .form-error {
    font-size: 0.8rem;
    color: #c75a5a;
    text-align: center;
    line-height: 1.4;
    margin-top: 0.5rem;
  }

  .form-error[hidden] {
    display: none;
  }

  .btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
  }

  @media (max-width: 768px) {
    .page-face { padding: 2.5rem 2rem; }
    .page-num { top: 1.5rem; right: 1.5rem; }
    .nav-controls { bottom: 1.5vh; }
    .contact-form { max-width: 100%; }
  }