:root {
  --blue: #061f78;
  --blue-dark: #03124a;
  --blue-soft: #123aa0;
  --yellow: #ffd414;
  --white: #ffffff;
  --light: #f4f7ff;
  --text: #101935;
  --muted: #5d6680;
  --line: rgba(6, 31, 120, 0.14);
  --shadow: 0 20px 45px rgba(3, 18, 74, 0.18);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  background: var(--light);
  color: var(--text);
  line-height: 1.6;
}

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

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

.hero {
  min-height: 100vh;
  background:
    radial-gradient(circle at 12% 15%, rgba(255, 212, 20, 0.18), transparent 22%),
    radial-gradient(circle at 90% 20%, rgba(255, 255, 255, 0.14), transparent 26%),
    linear-gradient(145deg, var(--blue), var(--blue-dark));
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "∑   √x   y = ax² + bx + c";
  position: absolute;
  inset: auto 4% 6% auto;
  color: rgba(255, 255, 255, 0.12);
  font-size: clamp(2rem, 6vw, 5rem);
  font-weight: 900;
  letter-spacing: 8px;
  pointer-events: none;
}

.nav {
  width: min(1180px, 94%);
  margin: 0 auto;
  padding: 24px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  position: relative;
  z-index: 2;
}

.logo {
  font-weight: 900;
  letter-spacing: -0.5px;
  font-size: 1.1rem;
}

.logo span {
  color: var(--yellow);
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  gap: 26px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.84);
}

.nav-whatsapp {
  background: var(--yellow);
  color: var(--blue-dark);
  padding: 11px 18px;
  border-radius: 999px;
  font-weight: 900;
}

.hero-content {
  width: min(1180px, 94%);
  margin: 0 auto;
  padding: 80px 0 120px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 52px;
  align-items: center;
  position: relative;
  z-index: 2;
}

.eyebrow,
.section-label {
  color: var(--yellow);
  text-transform: uppercase;
  font-weight: 900;
  letter-spacing: 1.5px;
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: clamp(3rem, 7vw, 6.8rem);
  line-height: 0.95;
  letter-spacing: -3px;
  max-width: 820px;
}

.subtitle {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  max-width: 680px;
  margin: 26px 0 34px;
  color: rgba(255, 255, 255, 0.9);
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 14px 22px;
  border-radius: 16px;
  font-weight: 900;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--yellow);
  color: var(--blue-dark);
  box-shadow: 0 12px 25px rgba(255, 212, 20, 0.28);
}

.btn-secondary {
  border: 2px solid rgba(255, 255, 255, 0.55);
  color: var(--white);
}

.hero-card {
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 30px;
  padding: 16px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.screen-bar {
  height: 40px;
  background: rgba(255, 255, 255, 0.18);
  border-radius: 20px 20px 0 0;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 16px;
}

.screen-bar span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--yellow);
}

.virtual-board {
  background: linear-gradient(160deg, #ffffff, #eaf0ff);
  color: var(--blue-dark);
  border-radius: 0 0 22px 22px;
  padding: 38px;
}

.virtual-board p {
  font-weight: 900;
  color: var(--blue-soft);
}

.virtual-board h2 {
  font-size: clamp(1.8rem, 3vw, 3rem);
  line-height: 1.05;
  margin: 8px 0 24px;
}

.formula {
  background: var(--blue);
  color: var(--yellow);
  padding: 20px;
  border-radius: 18px;
  font-weight: 900;
  font-size: 1.8rem;
  text-align: center;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 20px;
}

.board-grid span {
  background: var(--white);
  padding: 14px;
  border-radius: 14px;
  font-weight: 800;
  border: 1px solid var(--line);
}

.section {
  padding: 88px 0;
}

.problem {
  margin-top: -60px;
  position: relative;
  z-index: 3;
  padding-top: 0;
}

.problem-box {
  background: var(--white);
  border-radius: 28px;
  padding: 38px;
  display: grid;
  grid-template-columns: 1fr 0.8fr;
  gap: 36px;
  align-items: center;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}

.problem h2,
.section-heading h2,
.classroom h2,
.final-box h2 {
  color: var(--blue-dark);
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.1;
  letter-spacing: -1px;
}

.problem .section-label,
.section:not(.packages) .section-label,
.classroom .section-label,
.process .section-label {
  color: var(--blue-soft);
}

.problem p:last-child,
.section-heading p,
.classroom p {
  color: var(--muted);
  font-size: 1.08rem;
}

.section-heading {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 44px;
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.method-card,
.package-card,
.classroom-list,
.steps div {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: 0 12px 28px rgba(3, 18, 74, 0.08);
}

.method-card {
  padding: 26px;
}

.method-card span {
  display: inline-flex;
  color: var(--blue);
  background: rgba(255, 212, 20, 0.32);
  font-weight: 900;
  border-radius: 999px;
  padding: 4px 12px;
  margin-bottom: 18px;
}

.method-card h3 {
  color: var(--blue-dark);
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.method-card p,
.package-card p,
.package-card li {
  color: var(--muted);
}

.packages {
  background: linear-gradient(145deg, var(--blue-dark), var(--blue));
  color: var(--white);
}

.section-heading.light h2,
.section-heading.light p {
  color: var(--white);
}

.package-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.package-card {
  padding: 28px;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.package-card.featured {
  border: 3px solid var(--yellow);
  transform: translateY(-12px);
}

.tag {
  display: inline-flex;
  background: var(--blue);
  color: var(--yellow);
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 900;
  margin-bottom: 14px;
}

.package-card h3 {
  color: var(--blue-dark);
  font-size: 1.65rem;
  line-height: 1.15;
}

.package-card ul {
  list-style: none;
  display: grid;
  gap: 8px;
  padding-top: 4px;
}

.package-card li::before {
  content: "✓";
  color: #14a84a;
  font-weight: 900;
  margin-right: 8px;
}

.price {
  color: var(--blue);
  font-size: 2.6rem;
  font-weight: 900;
  margin-top: auto;
}

.price span {
  font-size: 1rem;
  color: var(--muted);
  text-transform: uppercase;
}

.btn-card {
  background: var(--blue);
  color: var(--white);
  width: 100%;
}


.other-packages-card {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.98), #eef4ff);
  border: 2px solid rgba(255, 212, 20, 0.75);
  border-radius: 28px;
  padding: 30px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
  color: var(--text);
  box-shadow: 0 18px 38px rgba(3, 18, 74, 0.16);
}

.other-packages-card h3 {
  color: var(--blue-dark);
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  line-height: 1.1;
  margin: 8px 0 10px;
}

.other-packages-card p {
  color: var(--muted);
  max-width: 760px;
  font-size: 1.05rem;
}

.tag-yellow {
  background: var(--yellow);
  color: var(--blue-dark);
}

.btn-other {
  background: var(--blue);
  color: var(--white);
  white-space: nowrap;
  box-shadow: 0 12px 25px rgba(6, 31, 120, 0.18);
}

.classroom-grid {
  display: grid;
  grid-template-columns: 0.8fr 1fr;
  gap: 38px;
  align-items: center;
}

.classroom-list {
  padding: 28px;
  display: grid;
  gap: 14px;
}

.classroom-list div {
  background: #f7f9ff;
  border-radius: 16px;
  padding: 16px;
  font-weight: 800;
  color: var(--blue-dark);
}

.steps {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 14px;
}

.steps div {
  padding: 22px;
  text-align: center;
}

.steps span {
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--yellow);
  color: var(--blue-dark);
  font-weight: 900;
  border-radius: 50%;
  margin-bottom: 14px;
}

.steps p {
  font-weight: 800;
  color: var(--blue-dark);
}

.final-cta {
  padding: 90px 0;
  background: var(--blue-dark);
  color: var(--white);
}

.final-box {
  background: linear-gradient(145deg, var(--blue), #092aa0);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 32px;
  padding: 48px;
  text-align: center;
  box-shadow: var(--shadow);
}

.final-box h2 {
  color: var(--white);
  max-width: 850px;
  margin: 0 auto 28px;
}

.final-box p {
  margin-top: 18px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 1.15rem;
}

.footer {
  background: #020c35;
  color: rgba(255, 255, 255, 0.75);
  text-align: center;
  padding: 24px;
}

@media (max-width: 980px) {
  .nav-links {
    display: none;
  }

  .hero-content,
  .problem-box,
  .classroom-grid {
    grid-template-columns: 1fr;
  }

  .method-grid,
  .package-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .package-card.featured {
    transform: none;
  }

  .other-packages-card {
    grid-template-columns: 1fr;
  }

  .btn-other {
    width: 100%;
    white-space: normal;
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .nav {
    padding: 18px 0;
  }

  .logo {
    font-size: 0.95rem;
  }

  .nav-whatsapp {
    padding: 9px 13px;
    font-size: 0.9rem;
  }

  .hero-content {
    padding: 54px 0 100px;
  }

  .hero h1 {
    letter-spacing: -1.8px;
  }

  .hero-actions,
  .btn {
    width: 100%;
  }

  .virtual-board {
    padding: 24px;
  }

  .board-grid,
  .method-grid,
  .package-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 64px 0;
  }

  .problem-box,
  .final-box {
    padding: 26px;
  }

  .package-card,
  .method-card,
  .other-packages-card {
    padding: 22px;
  }

  .price {
    font-size: 2.2rem;
  }
}