:root {
  --bg: #f4f1ec;
  --paper-noise-opacity: 0.045;
  --text: #111111;
  --muted: #6f6f6f;
  --button: #000000;
  --button-text: #ffffff;
  --brand: #d2d2d2;
  --shadow: 0 16px 34px rgba(0,0,0,0.08);
  --shadow-pressed: 0 8px 18px rgba(0,0,0,0.10);

  --hero-max-width: 920px;
  --hero-title-size: clamp(4rem, 12vw, 8rem);
  --hero-button-size: clamp(1.8rem, 6vw, 2.6rem);
  --hero-brand-size: clamp(2rem, 9vw, 5rem);

  --course-header-size: clamp(40px, 6vw, 72px);
  --course-text-size: clamp(24px, 3.8vw, 40px);
  --course-line-gap: 18px;
  --course-section-padding: 6vh;
}

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

html, body {
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: var(--paper-noise-opacity);
  background-image:
    radial-gradient(circle at 15% 20%, rgba(0,0,0,0.35) 0 0.5px, transparent 0.7px),
    radial-gradient(circle at 80% 30%, rgba(0,0,0,0.28) 0 0.45px, transparent 0.65px),
    radial-gradient(circle at 35% 75%, rgba(0,0,0,0.22) 0 0.4px, transparent 0.6px),
    radial-gradient(circle at 65% 60%, rgba(0,0,0,0.18) 0 0.35px, transparent 0.55px);
  background-size: 190px 190px, 230px 230px, 170px 170px, 210px 210px;
  mix-blend-mode: multiply;
  z-index: 0;
}

.hero-shell {
  position: relative;
  z-index: 1;
  width: 100%;
  display: flex;
  justify-content: center;
  padding: 2vh 5vw 5vh;
}

.hero-card {
  width: min(100%, var(--hero-max-width));
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3vh;
}

.hero-title {
  width: 100%;
  text-align: left;
  font-size: var(--hero-title-size);
  line-height: 0.9;
  font-weight: 800;
  letter-spacing: -0.06em;
  margin-top: 0.5vh;
}

.illustration-wrap {
  width: 100%;
  display: flex;
  justify-content: center;
}

.illustration-wrap img {
  width: min(100%, 760px);
  height: auto;
  display: block;
}

.enter-button {
  width: min(100%, 520px);
  min-height: 112px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--button);
  color: var(--button-text);
  text-decoration: none;
  border-radius: 999px;
  font-size: var(--hero-button-size);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-top: 0.5vh;
  box-shadow: var(--shadow);
  transition: transform 0.12s ease, box-shadow 0.12s ease, opacity 0.12s ease;
  -webkit-tap-highlight-color: transparent;
}

.enter-button:hover,
.enter-button:focus-visible {
  transform: translateY(-2px);
  opacity: 0.96;
}

.enter-button:active {
  transform: translateY(2px) scale(0.992);
  box-shadow: var(--shadow-pressed);
}

.brand {
  margin-top: 4vh;
  width: 100%;
  text-align: center;
  color: var(--brand);
  font-size: var(--hero-brand-size);
  font-weight: 800;
  letter-spacing: -0.05em;
  border-bottom: 4px solid #dddddd;
  padding-bottom: 1vh;
}

.hero-spacer {
  height: 3vh;
}

.language-switcher {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1002;
  display: flex;
  gap: 10px;
}

.language-switcher button {
  border: 0;
  background: rgba(17,17,17,0.92);
  color: #fff;
  padding: 10px 14px;
  border-radius: 999px;
  font-size: 14px;
  cursor: pointer;
}

.slide {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  padding: var(--course-section-padding);
  display: flex;
  flex-direction: column;
}

.slide-header {
  text-align: center;
  font-size: var(--course-header-size);
  font-weight: 700;
  letter-spacing: 1px;
  margin-top: 4vh;
}

.visual-group {
  margin-top: 8vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4vh;
}

.visual-group img {
  max-width: 80%;
  height: auto;
}

.text-group {
  margin-top: auto;
  margin-bottom: 8vh;
  text-align: center;
  font-size: var(--course-text-size);
  font-weight: 600;
  line-height: 1.3;
}

.text-group div {
  margin-bottom: var(--course-line-gap);
}

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

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

@media (orientation: landscape) {
  .visual-group img {
    max-width: 50%;
  }
  .text-group {
    font-size: clamp(22px, 2vw, 32px);
  }
}

@media (max-width: 480px) {
  .hero-shell {
    padding: 1.2vh 6vw 5vh;
  }
  .hero-card {
    gap: 2.2vh;
  }
  .hero-title {
    margin-top: 0;
  }
  .illustration-wrap img {
    width: min(100%, 720px);
  }
  .enter-button {
    width: 100%;
    min-height: 112px;
    font-size: 2.1rem;
  }
  .brand {
    margin-top: 3vh;
  }
}