/* =========================================================
   AI SNS ダッシュボード — マーキュリー国際高等学校
   Apple Support / User Guide 風スタイル
   ========================================================= */

:root {
  --color-bg: #ffffff;
  --color-text: #1d1d1f;
  --color-muted: #6e6e73;
  --color-faint: #86868b;
  --color-line: #ebebef;
  --color-line-soft: #f0f0f2;
  --color-surface: #f5f5f7;
  --accent-blue: #0071e3;
  --accent-blue-dark: #0063c6;
  --accent-green: #34c759;
  --accent-yellow: #ffb300;
  --radius-tile: 20px;
  --radius-lg: 28px;
  --max-width: 1120px;
  --font-base: -apple-system, BlinkMacSystemFont, "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-base);
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

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

/* ---------- ⓪ Tagline ---------- */
.tagline {
  border-bottom: 1px solid var(--color-line-soft);
  text-align: center;
  padding: 11px 24px;
  font-size: 13px;
  color: var(--color-muted);
  letter-spacing: 0.02em;
}

/* ---------- ① Header ---------- */
.header {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 22px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.header__brand { display: flex; align-items: center; gap: 14px; }
.header__logo {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  object-fit: cover;
  flex-shrink: 0;
}
.header__titles { display: flex; flex-direction: column; gap: 2px; }
.header__title { font-size: 21px; font-weight: 600; line-height: 1.2; }
.header__subtitle { font-size: 13px; color: var(--color-muted); line-height: 1.2; }
.version-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  border: 1px solid #e2e2e6;
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 12px;
  color: var(--color-muted);
  font-weight: 500;
  white-space: nowrap;
  flex-shrink: 0;
}
.version-badge__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-green);
}

/* ---------- ② Hero ---------- */
.hero {
  max-width: 920px;
  margin: 0 auto;
  padding: 72px 24px 64px;
  text-align: center;
}
.hero__title {
  margin: 0;
  font-size: clamp(32px, 4.6vw, 54px);
  font-weight: 600;
  line-height: 1.16;
  letter-spacing: -0.01em;
  text-wrap: balance;
}
.hero__lead {
  margin: 28px 0 0;
  font-size: clamp(20px, 2.4vw, 26px);
  color: var(--color-muted);
  font-weight: 400;
}

/* ---------- ③ 目的別タイル ---------- */
.tiles-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.tiles {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.tile {
  background: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-tile);
  padding: 30px 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.tile:hover {
  transform: translateY(-5px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.10);
  border-color: #dfe0e6;
}
.tile__icon {
  width: 64px;
  height: 64px;
  border-radius: 18px;
  background: var(--color-surface);
  display: flex;
  align-items: center;
  justify-content: center;
}
.tile__icon img { width: 40px; height: 40px; object-fit: contain; }
.tile__body { display: flex; flex-direction: column; gap: 7px; }
.tile__title { font-size: 20px; font-weight: 600; }
.tile__desc { font-size: 14px; line-height: 1.6; color: var(--color-muted); }

/* ---------- ④ SNS運用フロー ---------- */
.flow-section {
  max-width: var(--max-width);
  margin: 88px auto 0;
  padding: 0 24px;
}
.section-title {
  margin: 0 0 32px;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 600;
  text-align: center;
}
.section-title--left { text-align: left; margin-bottom: 28px; }
.flow {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 44px 32px;
}
.flow__steps {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  justify-content: center;
  gap: 10px;
}
.flow__step {
  flex: 1 1 150px;
  min-width: 140px;
  background: var(--color-bg);
  border-radius: 18px;
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-align: center;
  transition: transform .2s ease, box-shadow .2s ease;
}
.flow__step:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.08);
}
.flow__num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent-blue);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 16px;
}
.flow__num--green { background: var(--accent-green); }
.flow__label { font-size: 16px; font-weight: 600; }
.flow__arrow {
  display: flex;
  align-items: center;
  color: #c2c2c8;
  font-size: 22px;
}
.flow__note {
  margin: 26px 0 0;
  text-align: center;
  font-size: 13px;
  color: var(--color-faint);
}

/* ---------- ⑤ 今日のミッション ---------- */
.mission-section {
  max-width: var(--max-width);
  margin: 80px auto 0;
  padding: 0 24px;
}
.mission {
  background: rgba(255, 179, 0, 0.10);
  border: 1px solid rgba(255, 179, 0, 0.30);
  border-radius: var(--radius-lg);
  padding: 40px 36px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.mission__body {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 260px;
  flex: 1 1 360px;
}
.mission__eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 600;
  color: #a86b00;
  letter-spacing: 0.02em;
}
.mission__title {
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 600;
  line-height: 1.3;
}
.mission__note { font-size: 13px; color: var(--color-faint); }
.mission__btn {
  background: var(--accent-blue);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  padding: 15px 40px;
  border-radius: 999px;
  white-space: nowrap;
  transition: background .2s ease, transform .2s ease;
}
.mission__btn:hover { background: var(--accent-blue-dark); transform: translateY(-2px); }

/* ---------- ⑥ Chapter一覧 ---------- */
.chapters-section {
  max-width: var(--max-width);
  margin: 96px auto 0;
  padding: 0 24px;
}
.chapters {
  border: 1px solid var(--color-line);
  border-radius: var(--radius-tile);
  overflow: hidden;
}
.chapter {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 22px 26px;
  border-bottom: 1px solid var(--color-line-soft);
  transition: background .15s ease;
}
.chapter:last-child { border-bottom: none; }
.chapter:hover { background: #f7f7f9; }
.chapter__num {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-blue);
  letter-spacing: 0.04em;
  min-width: 80px;
}
.chapter__num--green { color: var(--accent-green); }
.chapter__title { font-size: 17px; font-weight: 500; flex: 1; }
.chapter__chevron { color: #c2c2c8; font-size: 18px; }

/* ---------- ⑦ Footer ---------- */
.footer {
  max-width: var(--max-width);
  margin: 96px auto 0;
  padding: 32px 24px 48px;
  border-top: 1px solid var(--color-line-soft);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 12px;
  color: var(--color-faint);
}
.footer__meta { display: flex; gap: 20px; flex-wrap: wrap; }

/* =========================================================
   レスポンシブ
   ========================================================= */

/* Tablet: 2列 */
@media (max-width: 900px) {
  .tiles { grid-template-columns: repeat(2, 1fr); }
}

/* SmartPhone: 1列 */
@media (max-width: 600px) {
  .tiles { grid-template-columns: 1fr; }
  .header { flex-wrap: wrap; }
  .hero { padding: 48px 24px 40px; }
  .flow__arrow { display: none; }
  .flow__steps { flex-direction: column; }
  .flow__step { width: 100%; }
}