/* =========================
RESPONSIVE
========================= */

@media (max-width: 1000px) {
.lesson-hero-grid {
grid-template-columns: 1fr;
}

.lesson-hero-right {
margin-top: 40px;
}
}

@media (max-width: 768px) {

.section {
padding: 60px 0;
}

.lesson-window,
.understanding-box {
padding: 30px;
}

.summary-grid,
.next-box {
grid-template-columns: 1fr;
flex-direction: column;
}

.next-path {
flex-wrap: wrap;
justify-content: center;
overflow: visible;
max-width: 100%;
}

.next-path span,
.next-path strong {
flex: 0 0 auto;
}

.start-section {
min-height: auto;
}
}

/* =========================
ADAPTIVE VIEWPORT HEIGHT
========================= */

@media (max-height: 900px) {

  .action-box h2 {
    font-size: clamp(28px, 4vw, 48px);
  }

  .action-box p {
    font-size: 16px;
  }

  .lesson-keyboard {
    height: 160px;
  }

  .top-zone {
    padding-top: 16px;
    gap: 8px;
  }

  .center-zone {
    gap: 12px;
    margin-top: 20px;
  }

}

/* =========================
CONTENT SYSTEM — RESPONSIVE
========================= */

@media (max-width: 980px) {

  .content-section {
    padding: 90px 0;
  }

  .lesson-hero-grid {
    grid-template-columns: 1fr;

    gap: 56px;
  }

  .lesson-hero-left {
    text-align: center;

    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .lesson-hero h1 {
    max-width: 10ch;
  }

  .lesson-description {
    max-width: 680px;
  }

  .next-box {
    flex-direction: column;
    align-items: flex-start;
  }

}

@media (max-width: 768px) {

  :root {
    --content-space-sm: 20px;
    --content-space-md: 28px;
    --content-space-lg: 40px;
  }

  .content-section {
    padding: 72px 0;
  }

  .lesson-hero h1 {
    font-size: clamp(54px, 14vw, 82px);

    line-height: 0.92;
  }

  .lesson-subtitle {
    font-size: 22px;
  }

  .lesson-description {
    font-size: 18px;

    line-height: 1.75;
  }

  .understanding-box h3 {
    font-size: 36px;
  }

  .summary-grid {
    grid-template-columns: 1fr;
  }

  .next-box {
    gap: 20px;
  }

  .next-path {
    flex-wrap: wrap;
    justify-content: center;
    overflow: visible;
    max-width: 100%;
  }

  .next-path span,
  .next-path strong {
    flex: 0 0 auto;
  }

}

@media (max-width: 900px) {

  .control-tip {
    display: none;
  }

}

@media (max-width: 768px) {
  .section {
    padding: 46px 0;
  }

  .content-section {
    padding: 56px 0;
  }

  .action-box h2 {
    font-size: clamp(34px, 10vw, 52px);
    line-height: 0.95;
  }

  .action-box p {
    max-width: 100%;
    font-size: 16px;
    line-height: 1.55;
  }
}

@media (max-width: 768px) {
  .action-box h2 {
    font-size: clamp(34px, 9vw, 50px);
    line-height: 0.96;
    letter-spacing: -0.045em;
    margin-bottom: 14px;
  }

  .action-box p {
    font-size: 16px;
    line-height: 1.5;
  }

  .action-lead {
    gap: 2px;
  }
}

@media (max-width: 420px) {
  .action-box h2 {
    font-size: clamp(30px, 8.5vw, 44px);
    line-height: 0.98;
    margin-bottom: 12px;
  }

  .action-box p {
    font-size: 15.5px;
    line-height: 1.48;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .section {
    padding: 64px 0;
  }

  .content-section {
    padding: 70px 0;
  }

  .action-box h2 {
    font-size: clamp(38px, 6vw, 58px);
    line-height: 0.96;
    margin-bottom: 16px;
  }

  .action-box p {
    font-size: 16.5px;
    line-height: 1.58;
    max-width: 620px;
  }

  .lesson-hero h1 {
    font-size: clamp(56px, 8vw, 78px);
  }

  .lesson-description {
    font-size: 17px;
    line-height: 1.65;
  }

  .next-path {
    flex-wrap: wrap;
    justify-content: center;
    overflow: visible;
    max-width: 100%;
  }

  .next-path span,
  .next-path strong {
    flex: 0 0 auto;
  }
}