*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --ink: #111;
  --sub: #6b6b6b;
  --line: #e8e8e8;
  --ph: #f3f3f3;
  --wrap: 1280px;
  --pad: min(7.5vw, 96px);
  --gap: clamp(72px, 9vw, 128px);
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: "Inter", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", Meiryo, sans-serif;
  font-size: 17px;
  line-height: 2;
  font-feature-settings: "palt";
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.site-header .inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 16px var(--pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.site-name {
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  line-height: 1.4;
}

.header-cta {
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  padding: 8px 16px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  line-height: 1.4;
  white-space: nowrap;
  transition: background 0.2s, color 0.2s;
}

.header-cta:hover {
  background: var(--ink);
  color: #fff;
}

/* ---------- Layout ---------- */

main,
.site-footer {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 var(--pad);
}

section {
  padding: var(--gap) 0;
}

section.hero {
  padding-top: clamp(48px, 7vw, 104px);
}

/* ---------- Type ---------- */

.hero-copy,
h1,
h2,
h3 {
  font-weight: 700;
  letter-spacing: 0.01em;
  margin: 0;
  word-break: auto-phrase;
  text-wrap: balance;
}

.hero-copy {
  font-size: clamp(30px, 5.2vw, 68px);
  line-height: 1.35;
}

h2 {
  font-size: clamp(28px, 4.2vw, 54px);
  line-height: 1.4;
  margin-bottom: clamp(40px, 5vw, 72px);
}

h3 {
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.5;
  margin: 72px 0 24px;
}

h2 + h3,
.num + h3 {
  margin-top: 0;
}

p {
  margin: 0 0 1.6em;
}

p:last-child {
  margin-bottom: 0;
}

strong {
  font-weight: 700;
}

.lead {
  font-size: clamp(18px, 2vw, 24px);
  font-weight: 700;
  line-height: 1.7;
  margin: 32px 0 0;
}

.meta {
  font-size: 14px;
  color: var(--sub);
  line-height: 1.9;
  margin: 28px 0 0;
}

.hero .meta {
  margin-bottom: clamp(48px, 6vw, 80px);
}

.meta b {
  color: var(--ink);
}

/* 全幅で大きく見せる一文 */
.big {
  font-size: clamp(22px, 3.2vw, 42px);
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.01em;
  margin: clamp(32px, 5vw, 72px) 0;
  word-break: auto-phrase;
  text-wrap: balance;
}

.note {
  font-size: 14px;
  color: var(--sub);
  line-height: 1.9;
}

/* 「〜」の声 */
.voices {
  list-style: none;
  margin: 0 0 1.6em;
  padding: 0 0 0 20px;
  border-left: 2px solid var(--ink);
  font-size: clamp(17px, 1.5vw, 20px);
  font-weight: 700;
  line-height: 1.8;
}

.voices li {
  margin: 0 0 0.5em;
}

.voices li:last-child {
  margin-bottom: 0;
}

ul.plain {
  margin: 0 0 1.6em;
  padding: 0;
  list-style: none;
}

ul.plain li {
  padding-left: 1.2em;
  position: relative;
}

ul.plain li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.95em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--ink);
}

.num {
  display: block;
  font-size: 13px;
  font-weight: 700;
  color: var(--sub);
  letter-spacing: 0.08em;
  margin: 72px 0 8px;
}

h2 + .num {
  margin-top: 0;
}

.flow {
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 700;
  line-height: 2;
}

/* ---------- CTA ---------- */

.cta {
  margin-top: 56px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  background: var(--ink);
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
  text-decoration: none;
  padding: 18px 32px;
  border-radius: 999px;
  transition: opacity 0.2s;
}

.btn::after {
  content: "→";
}

.btn:hover {
  opacity: 0.75;
}

.cta .note {
  margin-top: 16px;
}

.text-link {
  font-weight: 700;
  text-underline-offset: 5px;
}

/* ---------- Placeholders ---------- */

.ph {
  background: var(--ph);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #9a9a9a;
  font-size: 13px;
  line-height: 1.6;
  padding: 16px;
  margin: clamp(40px, 6vw, 80px) 0;
  aspect-ratio: 16 / 9;
}

.portrait-wrap {
  max-width: 360px;
  margin: 0 0 32px;
}

.portrait-wrap img {
  aspect-ratio: 4 / 5;
  margin: 0;
}

.portrait-wrap figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--sub);
}

.portrait-wrap + h3 {
  margin-top: 0;
}

img.ph {
  display: block;
  width: 100%;
  height: auto;
  padding: 0;
  object-fit: cover;
  object-position: 56% 50%;
}

.ph.wide {
  aspect-ratio: 2 / 1;
}

.video {
  margin: clamp(32px, 4vw, 56px) 0;
  aspect-ratio: 16 / 9;
  border-radius: 12px;
  overflow: hidden;
  background: var(--ph);
}

.video iframe {
  width: 100%;
  height: 100%;
  border: 0;
  display: block;
}

/* ---------- Price ---------- */

.price {
  margin: 0 0 48px;
  border-top: 1px solid var(--ink);
}

.price div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.price dt {
  font-weight: 700;
}

.price dd {
  margin: 0;
  font-size: clamp(28px, 3.4vw, 44px);
  font-weight: 700;
  line-height: 1.3;
}

.price dd small {
  font-size: 14px;
  font-weight: 400;
  color: var(--sub);
  margin-left: 6px;
}

/* ---------- 補足（学生・保護者の方へ） ---------- */

section.notes {
  padding-top: 0;
}

.note-block {
  background: #f7f7f7;
  border-radius: 12px;
  padding: 28px 28px 30px;
  font-size: 14px;
  line-height: 1.9;
  color: #444;
}

.note-block + .note-block {
  margin-top: 16px;
}

.note-block h3 {
  font-size: 15px;
  margin: 0 0 14px;
  color: var(--ink);
}

.note-block p,
.note-block .voices {
  margin-bottom: 0.9em;
}

.note-block .voices {
  font-size: inherit;
  font-weight: 400;
  line-height: inherit;
  padding-left: 14px;
  border-left: 1px solid #bbb;
}

.note-block .voices li {
  margin: 0;
}

/* ---------- FAQ ---------- */

.faq {
  border-top: 1px solid var(--ink);
}

.faq details {
  border-bottom: 1px solid var(--line);
}

.faq summary {
  cursor: pointer;
  list-style: none;
  font-weight: 700;
  line-height: 1.6;
  padding: 22px 32px 22px 0;
  position: relative;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 22px;
  font-weight: 400;
}

.faq details[open] summary::after {
  content: "−";
}

.faq .answer {
  padding: 0 0 28px;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  padding-top: 32px;
  padding-bottom: 48px;
  font-size: 12px;
  color: var(--sub);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
}

/* ---------- 特定商取引法に基づく表記 ---------- */

.legal {
  margin: 0;
  border-top: 1px solid var(--ink);
  font-size: 15px;
  line-height: 1.9;
}

.legal div {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.legal dt {
  font-weight: 700;
  margin-bottom: 4px;
}

.legal dd {
  margin: 0;
}

/* ---------- Scroll reveal ---------- */

.js section > * {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1);
}

.js section > .in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .js section > * {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ---------- Desktop: 見出しは全幅、本文は右に寄せる ---------- */

@media (min-width: 900px) {
  body {
    font-size: 18px;
  }

  br.sp {
    display: none;
  }

  section {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    column-gap: 56px;
    align-items: start;
  }

  section > * {
    grid-column: 2;
  }

  section > .hero-copy,
  section > h2,
  section > .big,
  section > .ph,
  section > .video {
    grid-column: 1 / -1;
  }

  /* 小見出しは左、本文は右 */
  section > h3,
  section > .num {
    grid-column: 1;
  }

  section > h3 {
    margin-bottom: 0;
  }

  section > h3 + * {
    margin-top: 72px;
  }

  section > h2 + h3 + *,
  section > .num + h3 + * {
    margin-top: 0;
  }

  /* 講師写真は左、プロフィールは右 */
  section > .portrait-wrap {
    grid-column: 1;
    grid-row: span 6;
    margin: 0;
  }

  section > .portrait-wrap + h3 {
    grid-column: 2;
    margin-bottom: 24px;
  }

  section > .portrait-wrap + h3 + * {
    margin-top: 0;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 16px;
  }

  .btn {
    width: 100%;
    padding: 18px 20px;
  }
}