:root {
    --gold: #D4A843;
    --red: #C0392B;
    --white: #F5F0E8;
    --dark: #080808;
    --mid: #111111;
    --grey: #888;
  }

  * { margin: 0; padding: 0; box-sizing: border-box; }

  html { scroll-behavior: smooth; }

  body {
    background: var(--dark);
    color: var(--white);
    font-family: 'Barlow', sans-serif;
    overflow-x: hidden;
  }

  /* ── SCROLLBAR ── */
  ::-webkit-scrollbar { width: 4px; }
  ::-webkit-scrollbar-track { background: #000; }
  ::-webkit-scrollbar-thumb { background: var(--gold); }

  /* ── NAV ── */
  nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 3rem;
    background: linear-gradient(to bottom, rgba(0,0,0,0.9), transparent);
    backdrop-filter: blur(4px);
  }

  .nav-logo {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 1.6rem;
    letter-spacing: 4px;
    color: var(--gold);
  }

  .nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
  }

  .nav-links a {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.85rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: rgba(245,240,232,0.6);
    text-decoration: none;
    transition: color 0.3s;
  }

  .nav-links a:hover { color: var(--gold); }

  /* ── HERO ── */
  .hero {
    height: 100vh;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: 0 8vw;
    overflow: hidden;
  }

  .hero-bg {
    position: absolute;
    inset: 0;
    background:
      radial-gradient(ellipse at 70% 50%, rgba(192,57,43,0.15) 0%, transparent 60%),
      radial-gradient(ellipse at 20% 80%, rgba(212,168,67,0.08) 0%, transparent 50%),
      linear-gradient(135deg, #000 0%, #0d0d0d 50%, #060606 100%);
  }

  /* stadium lines texture */
  .hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image: 
      repeating-linear-gradient(
        0deg,
        transparent,
        transparent 60px,
        rgba(255,255,255,0.015) 60px,
        rgba(255,255,255,0.015) 61px
      );
  }

  .hero-number {
    position: absolute;
    right: 5vw;
    top: 50%;
    transform: translateY(-50%);
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(200px, 30vw, 420px);
    color: rgba(212,168,67,0.05);
    line-height: 1;
    pointer-events: none;
    user-select: none;
    letter-spacing: -10px;
  }

  .hero-eyebrow {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.8rem;
    letter-spacing: 6px;
    text-transform: uppercase;
    color: var(--gold);
    margin-bottom: 1.5rem;
    opacity: 0;
    animation: fadeUp 0.8s 0.3s forwards;
  }

  .hero-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(70px, 12vw, 160px);
    line-height: 0.9;
    letter-spacing: 2px;
    position: relative;
    z-index: 1;
    opacity: 0;
    animation: fadeUp 0.8s 0.5s forwards;
  }

  .hero-title .line-red { color: var(--red); }
  .hero-title .line-gold { color: var(--gold); }

  .hero-sub {
    margin-top: 2rem;
    max-width: 520px;
    font-size: 1.05rem;
    font-weight: 300;
    line-height: 1.7;
    color: rgba(245,240,232,0.65);
    opacity: 0;
    animation: fadeUp 0.8s 0.7s forwards;
  }

  .hero-badge {
    margin-top: 3rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    opacity: 0;
    animation: fadeUp 0.8s 0.9s forwards;
  }

  .badge-item {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .badge-num {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 2.5rem;
    color: var(--gold);
    line-height: 1;
  }

  .badge-label {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--grey);
  }

  .badge-sep {
    width: 1px;
    height: 50px;
    background: rgba(255,255,255,0.15);
  }

  .scroll-hint {
    position: absolute;
    bottom: 2.5rem;
    left: 8vw;
    display: flex;
    align-items: center;
    gap: 1rem;
    opacity: 0;
    animation: fadeUp 0.8s 1.2s forwards;
  }

  .scroll-line {
    width: 60px;
    height: 1px;
    background: var(--gold);
    animation: expandLine 1.5s 2s infinite alternate;
  }

  .scroll-text {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--grey);
  }

  /* ── SECTION BASE ── */
  section {
    padding: 8rem 8vw;
    position: relative;
  }

  .section-tag {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 5px;
    text-transform: uppercase;
    color: var(--gold);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1rem;
  }

  .section-tag::before {
    content: '';
    display: block;
    width: 30px;
    height: 1px;
    background: var(--gold);
  }

  .section-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(48px, 6vw, 90px);
    line-height: 1;
    letter-spacing: 2px;
    margin-bottom: 3rem;
  }

  /* ── HISTORIA ── */
  .historia {
    background: var(--mid);
    border-top: 1px solid rgba(255,255,255,0.05);
    border-bottom: 1px solid rgba(255,255,255,0.05);
  }

  .historia-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6rem;
    align-items: start;
  }

  .historia-text p {
    font-size: 1rem;
    font-weight: 300;
    line-height: 1.9;
    color: rgba(245,240,232,0.7);
    margin-bottom: 1.5rem;
  }

  .historia-text p strong {
    color: var(--gold);
    font-weight: 600;
  }

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

  .timeline-item {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 1.5rem;
    padding: 2rem 0;
    border-bottom: 1px solid rgba(255,255,255,0.07);
    transition: background 0.3s;
  }

  .timeline-item:last-child { border-bottom: none; }

  .t-year {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 2rem;
    color: var(--gold);
    line-height: 1.1;
  }

  .t-desc {
    font-size: 0.9rem;
    font-weight: 300;
    line-height: 1.7;
    color: rgba(245,240,232,0.65);
    padding-top: 0.3rem;
  }

  .t-desc strong {
    color: var(--white);
    font-weight: 600;
    display: block;
    font-size: 1rem;
    margin-bottom: 0.3rem;
  }

  /* ── CONCEPTOS ── */
  .conceptos {
    background: var(--dark);
  }

  .conceptos-intro {
    max-width: 600px;
    font-size: 1rem;
    font-weight: 300;
    line-height: 1.8;
    color: rgba(245,240,232,0.6);
    margin-bottom: 5rem;
  }

  .concepto-block {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 5rem;
    align-items: center;
    padding: 5rem 0;
    border-top: 1px solid rgba(255,255,255,0.06);
  }

  .concepto-block:last-child { border-bottom: 1px solid rgba(255,255,255,0.06); }

  .concepto-block.reverse { direction: rtl; }
  .concepto-block.reverse > * { direction: ltr; }

  .concepto-num {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 8rem;
    color: rgba(212,168,67,0.1);
    line-height: 1;
    margin-bottom: -2rem;
  }

  .concepto-nombre {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(36px, 4vw, 60px);
    line-height: 1;
    margin-bottom: 1.5rem;
    color: var(--white);
  }

  .concepto-nombre span { color: var(--gold); }

  .concepto-desc {
    font-size: 0.95rem;
    font-weight: 300;
    line-height: 1.9;
    color: rgba(245,240,232,0.65);
    margin-bottom: 1.5rem;
  }

  .concepto-desc strong { color: var(--gold); }

  .concepto-ejemplo {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    background: rgba(212,168,67,0.06);
    border-left: 3px solid var(--gold);
    padding: 1.2rem 1.5rem;
    border-radius: 0 6px 6px 0;
    margin-top: 1rem;
  }

  .ej-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
    margin-top: 0.1rem;
  }

  .ej-text {
    font-size: 0.88rem;
    font-style: italic;
    color: rgba(245,240,232,0.7);
    line-height: 1.7;
  }

  .ej-text strong {
    font-style: normal;
    color: var(--gold);
    font-size: 0.78rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    display: block;
    margin-bottom: 0.3rem;
  }

  /* visual placeholder para imágenes */
  .concepto-visual {
    position: relative;
    aspect-ratio: 4/3;
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 8px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
  }

  .concepto-visual::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, rgba(212,168,67,0.07), transparent 70%);
  }

  .visual-icon {
    font-size: 4rem;
    opacity: 0.6;
    position: relative;
  }

  .visual-label {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--grey);
    text-align: center;
    padding: 0 2rem;
    position: relative;
  }

  /* concepto 1: física */
  .vis-fisica {
    background: linear-gradient(135deg, #0a0a0a, #0f0e0a);
  }

  /* SVG diagrams inside visuals */
  .vis-svg {
    width: 80%;
    height: 70%;
    position: relative;
  }

  /* ── DATO FREAK ── */
  .dato-freak {
    background: var(--red);
    padding: 4rem 8vw;
    position: relative;
    overflow: hidden;
  }

  .dato-freak::before {
    content: 'DATO FREAK';
    position: absolute;
    right: -2rem;
    top: 50%;
    transform: translateY(-50%) rotate(90deg);
    font-family: 'Bebas Neue', sans-serif;
    font-size: 8rem;
    color: rgba(0,0,0,0.2);
    letter-spacing: 10px;
    pointer-events: none;
  }

  .freak-inner {
    display: flex;
    align-items: center;
    gap: 4rem;
  }

  .freak-num {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 6rem;
    color: #fff;
    line-height: 1;
    flex-shrink: 0;
  }

  .freak-text {
    font-size: 1.1rem;
    font-weight: 300;
    line-height: 1.8;
    color: rgba(255,255,255,0.85);
  }

  .freak-text strong { font-weight: 700; color: #fff; }

  /* ── VIDEO SECTION ── */
  .video-section {
    background: var(--mid);
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.05);
  }

  .video-wrapper {
    margin: 0 auto;
    max-width: 900px;
    aspect-ratio: 16/9;
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    overflow: hidden;
    position: relative;
  }

  .video-wrapper::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, rgba(192,57,43,0.1), transparent 70%);
  }

  .video-placeholder-icon { font-size: 5rem; opacity: 0.5; }

  .video-wrapper video {
    border-radius: 10px;
    width: 100%;
    height: 100%;
  }

  /* ── DATOS EXTRA ── */
  .datos-extra {
    background: var(--dark);
  }

  .stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2px;
    margin-top: 3rem;
    border: 2px solid rgba(255,255,255,0.06);
  }

  .stat-card {
    background: rgba(255,255,255,0.02);
    padding: 3rem 2rem;
    border: 1px solid rgba(255,255,255,0.04);
    text-align: center;
    transition: background 0.3s;
  }

  .stat-card:hover { background: rgba(212,168,67,0.05); }

  .stat-val {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 3.5rem;
    color: var(--gold);
    line-height: 1;
    display: block;
  }

  .stat-unit {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 1.2rem;
    color: var(--red);
  }

  .stat-lbl {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--grey);
    margin-top: 0.5rem;
    display: block;
    line-height: 1.5;
  }

  /* ── FREAK FACTS ── */
  .freak-facts {
    background: var(--mid);
    padding: 6rem 8vw;
    border-top: 1px solid rgba(255,255,255,0.05);
  }

  .facts-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
  }

  .fact-card {
    padding: 2.5rem;
    border: 1px solid rgba(255,255,255,0.07);
    border-radius: 4px;
    position: relative;
    overflow: hidden;
    transition: border-color 0.3s, transform 0.3s;
  }

  .fact-card:hover {
    border-color: var(--gold);
    transform: translateY(-4px);
  }

  .fact-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--gold), transparent);
  }

  .fact-emoji { font-size: 2.5rem; margin-bottom: 1rem; display: block; }

  .fact-title {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--white);
    margin-bottom: 0.8rem;
  }

  .fact-desc {
    font-size: 0.88rem;
    font-weight: 300;
    line-height: 1.7;
    color: rgba(245,240,232,0.6);
  }

  /* ── CIERRE ── */
  .cierre {
    min-height: 60vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 8rem 8vw;
    background: #000;
    position: relative;
    overflow: hidden;
  }

  .cierre::before {
    content: 'SIUUU';
    position: absolute;
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(100px, 20vw, 250px);
    color: rgba(212,168,67,0.03);
    letter-spacing: 20px;
    pointer-events: none;
  }

  .cierre-title {
    font-family: 'Bebas Neue', sans-serif;
    font-size: clamp(50px, 8vw, 110px);
    line-height: 1;
    letter-spacing: 3px;
    color: var(--gold);
    position: relative;
  }

  .cierre-sub {
    font-size: 1rem;
    font-weight: 300;
    color: var(--grey);
    margin-top: 1.5rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    font-family: 'Barlow Condensed', sans-serif;
    position: relative;
  }

  .cierre-line {
    width: 1px;
    height: 80px;
    background: linear-gradient(to bottom, var(--gold), transparent);
    margin: 2.5rem auto 0;
    position: relative;
  }

  /* ── FOOTER ── */
  footer {
    padding: 2rem 8vw;
    background: #000;
    border-top: 1px solid rgba(255,255,255,0.06);
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .footer-logo {
    font-family: 'Bebas Neue', sans-serif;
    font-size: 1.2rem;
    letter-spacing: 4px;
    color: rgba(255,255,255,0.2);
  }

  .footer-credit {
    font-family: 'Barlow Condensed', sans-serif;
    font-size: 0.75rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: rgba(255,255,255,0.2);
  }

  /* ── ANIMATIONS ── */
  @keyframes fadeUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
  }

  @keyframes expandLine {
    from { width: 40px; }
    to { width: 80px; }
  }

  .reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
  }

  .reveal.visible {
    opacity: 1;
    transform: translateY(0);
  }

  /* ── BALL TRAJECTORY SVG ── */
  .trajectory-wrap {
    width: 100%;
    aspect-ratio: 4/3;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.4);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: 8px;
    overflow: hidden;
    position: relative;
  }

  .trajectory-wrap svg {
    width: 90%;
    height: 90%;
  }

  /* ── RESPONSIVE BASICS ── */
  @media (max-width: 900px) {
    nav { padding: 1rem 1.5rem; }
    .nav-links { display: none; }
    section { padding: 5rem 5vw; }
    .historia-grid,
    .concepto-block,
    .concepto-block.reverse { grid-template-columns: 1fr; gap: 3rem; direction: ltr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .facts-grid { grid-template-columns: 1fr; }
    .freak-inner { flex-direction: column; gap: 1.5rem; text-align: center; }
    footer { flex-direction: column; gap: 1rem; text-align: center; }
  }