/* =========================================================
   G模試  |  ランディングページ (ルート / = index.html) 専用スタイル
   既存アプリ styles.css のデザイントークン（白＋エメラルド/ブルー）を流用。
   アプリ本体には一切影響しない独立ファイル。
   ========================================================= */
:root {
  --bg: #ffffff;
  --bg-soft: #f7f6f1;
  --bg-card: #ffffff;
  --bg-card-hi: #faf8f1;
  --ink: #1a1a1a;
  --ink-muted: #555555;
  --ink-dim: #8a8780;
  --emerald: #0fa37c;
  --emerald-soft: #2dd4a8;
  --amber: #d97706;
  --red: #c0392b;
  --blue: #2b6cb0;
  --blue-bright: #3182ce;
  --gold: #b8901c;
  --gold-bright: #d4af37;
  --line: #e3e0d4;
  --shadow: 0 4px 14px rgba(40,30,10,.08);
  --shadow-lg: 0 10px 28px rgba(40,30,10,.12);
  --radius: 10px;
  --radius-lg: 16px;
  --font-jp: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  --font-en: "Trajan Pro", "Times New Roman", "Cinzel", serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-jp);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(circle at 15% -5%, rgba(45,212,168,0.10) 0%, transparent 40%),
    radial-gradient(circle at 90% 8%, rgba(43,108,176,0.06) 0%, transparent 42%);
}
a { color: inherit; }
img { max-width: 100%; display: block; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.section { padding: 72px 0; }
/* アンカー遷移時に固定ヘッダーで見出しが隠れないように */
section[id], [id].section { scroll-margin-top: 84px; }
.section-head { text-align: center; margin-bottom: 40px; }
.section-eyebrow {
  font-family: var(--font-en);
  letter-spacing: 0.35em;
  font-size: 12px;
  color: var(--emerald);
  text-transform: uppercase;
  font-weight: 700;
}
.section-title {
  font-size: 28px;
  font-weight: 800;
  margin: 10px 0 0;
  letter-spacing: 0.02em;
}
.section-sub { color: var(--ink-muted); font-size: 15px; margin: 10px 0 0; }

/* ========== Header ========== */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.86);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.hex {
  width: 42px; height: 42px;
  background: linear-gradient(135deg, var(--blue) 0%, var(--blue-bright) 100%);
  clip-path: polygon(25% 6%, 75% 6%, 100% 50%, 75% 94%, 25% 94%, 0 50%);
  display: flex; align-items: center; justify-content: center;
}
.hex-inner {
  width: 26px; height: 26px;
  background: var(--bg);
  clip-path: polygon(25% 6%, 75% 6%, 100% 50%, 75% 94%, 25% 94%, 0 50%);
  position: relative;
}
.hex-inner::before {
  content: "G";
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-en); font-weight: bold;
  color: var(--blue-bright); font-size: 16px;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-size: 19px; font-weight: 900; letter-spacing: 0.04em; }
.brand-tag { font-size: 10px; letter-spacing: 0.2em; color: var(--ink-dim); font-family: var(--font-en); }

/* ========== Buttons ========== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-weight: 800; font-size: 15px; text-decoration: none;
  padding: 13px 26px; border-radius: 999px; border: 1.5px solid transparent;
  transition: transform .12s ease, box-shadow .12s ease, background .12s ease;
  white-space: nowrap; cursor: pointer;
}
.btn:active { transform: scale(0.97); }
.btn-primary {
  background: linear-gradient(135deg, var(--emerald) 0%, var(--emerald-soft) 100%);
  color: #fff; box-shadow: 0 6px 18px rgba(15,163,124,0.30);
}
.btn-primary:hover { box-shadow: 0 10px 26px rgba(15,163,124,0.40); transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--emerald); border-color: var(--emerald); }
.btn-ghost:hover { background: rgba(15,163,124,0.06); }
.btn-header { padding: 10px 20px; font-size: 14px; }
.header-nav { display: flex; align-items: center; gap: 10px; }
.btn-lg { font-size: 17px; padding: 16px 34px; }

/* ===== 学習支援ドロップダウン（用語集／合格率／練習問題） =====
   CSP対応のためJSを使わず、チェックボックス（クリック）＋ :hover で開閉する。 */
.nav-learn { position: relative; display: flex; align-items: center; }
.nav-learn-check { position: absolute; width: 0; height: 0; opacity: 0; pointer-events: none; }
.nav-learn-btn { cursor: pointer; gap: 6px; user-select: none; }
.nav-caret { font-size: 11px; line-height: 1; transition: transform .2s ease; }
.nav-learn-menu {
  position: absolute; top: calc(100% + 10px); left: 0;
  min-width: 184px; padding: 8px;
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  box-shadow: var(--shadow-lg);
  display: flex; flex-direction: column; gap: 2px;
  opacity: 0; visibility: hidden; transform: translateY(-8px);
  transition: opacity .18s ease, transform .18s ease, visibility .18s ease;
  z-index: 60;
}
.nav-learn-menu a {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 14px; border-radius: 10px;
  text-decoration: none; color: var(--ink);
  font-weight: 700; font-size: 14px; white-space: nowrap;
  transition: background .14s ease, color .14s ease;
}
.nav-learn-menu a:hover { background: rgba(15,163,124,0.08); color: var(--emerald); }
/* 開いた状態：PCはホバー/フォーカス、共通はチェック（クリック/タップ） */
.nav-learn:hover .nav-learn-menu,
.nav-learn:focus-within .nav-learn-menu,
.nav-learn-check:checked ~ .nav-learn .nav-learn-menu {
  opacity: 1; visibility: visible; transform: translateY(0);
}
.nav-learn:hover .nav-caret,
.nav-learn-check:checked ~ .nav-learn .nav-caret { transform: rotate(180deg); }
/* メニュー内「アプリ」はPCでは非表示（PCはヘッダーの「アプリを開く」ボタンを使う） */
.nav-learn-app { display: none; }
/* 三本線（ハンバーガー）はPCでは非表示、スマホで表示する */
.nav-burger { display: none; }

/* ========== Hero ========== */
.hero {
  text-align: center;
  padding: 72px 0 64px;
  background:
    linear-gradient(180deg, rgba(45,212,168,0.10), transparent 55%),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-soft) 100%);
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 7px 16px; font-size: 13px; font-weight: 700; color: var(--ink-muted);
  box-shadow: var(--shadow); margin-bottom: 26px;
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--emerald); }

/* ===== 最新版バッジ（差別化アピール）：色＋アニメーションで強調 ===== */
.hero-badge--new {
  border-color: var(--emerald);
  color: var(--ink);
  background: linear-gradient(120deg, #ffffff 0%, #ecfbf5 50%, #ffffff 100%);
  background-size: 220% 100%;
  box-shadow: 0 6px 20px rgba(15,163,124,0.22);
  animation: rise .8s cubic-bezier(.2,.7,.2,1) forwards, badgeSheen 4.5s linear 1s infinite;
}
.hero-badge--new strong {
  color: var(--emerald); font-weight: 900; letter-spacing: 0.02em;
}
.hero-badge--new .dot {
  background: var(--emerald);
  animation: badgePulse 1.8s ease-in-out infinite;
}
.badge-new {
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--font-en); font-size: 10px; font-weight: 900; letter-spacing: 0.08em;
  color: #fff; background: linear-gradient(135deg, var(--emerald), var(--emerald-soft));
  padding: 3px 8px; border-radius: 999px; line-height: 1;
  box-shadow: 0 2px 6px rgba(15,163,124,0.35);
}
@keyframes badgePulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(15,163,124,0.45); }
  50%      { box-shadow: 0 0 0 7px rgba(15,163,124,0); }
}
@keyframes badgeSheen {
  0%   { background-position: 120% 0; }
  60%, 100% { background-position: -120% 0; }
}
.hero h1 {
  font-size: 46px; line-height: 1.3; font-weight: 900; letter-spacing: 0.01em;
  margin: 0 0 20px;
}
.hero h1 .em { color: var(--emerald); }
.hero-h1-main { display: block; }
.hero-h1-sub {
  display: block; margin-top: 12px;
  font-size: clamp(16px, 0.5em, 24px); font-weight: 800;
  color: var(--ink-muted); letter-spacing: 0.02em;
}
/* サブ文の改行はスマホのみ（PCは1行で表示） */
.hero-h1-sub .sp-br { display: none; }

/* ===== Hero 登場アニメーション ===== */
.anim { opacity: 0; transform: translateY(18px); animation: rise .8s cubic-bezier(.2,.7,.2,1) forwards; }
.hero-badge.anim { animation-delay: .05s; }
.hero h1.anim      { animation-delay: .18s; }
.hero-sub.anim     { animation-delay: .34s; }
.hero-cta.anim     { animation-delay: .50s; }
.hero-note.anim    { animation-delay: .64s; }
@keyframes rise {
  to { opacity: 1; transform: translateY(0); }
}
/* タイトルのマーカー（下線）が左から引かれる演出 */
.hero h1 .hl {
  position: relative; padding: 0 .08em; white-space: nowrap;
}
.hero h1 .hl::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0.06em; height: 38%;
  background: rgba(45,212,168,0.45); z-index: -1; border-radius: 2px;
  transform: scaleX(0); transform-origin: left center;
  animation: sweep .7s ease forwards; animation-delay: 1.0s;
}
@keyframes sweep { to { transform: scaleX(1); } }
/* スマホ・ヒーロー背景のオーロラ風グロー */
@keyframes heroAura {
  0%   { transform: translate(-6%, 0)  scale(1);    opacity: .6; }
  100% { transform: translate(6%, 5%)  scale(1.18); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  .anim { opacity: 1; transform: none; animation: none; }
  .hero h1 .hl::after { transform: scaleX(1); animation: none; }
  .hero::before { animation: none; }
  .voice-track { animation: none; }
  .value-step:hover { transform: none; }
  .hero-badge--new { opacity: 1; transform: none; animation: none; }
  .hero-badge--new .dot { animation: none; }
}
.hero-sub {
  font-size: 18px; color: var(--ink-muted); max-width: 860px; margin: 0 auto 20px;
  line-height: 1.9;
}
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero-note { margin-top: 18px; font-size: 13px; color: var(--ink-dim); }

/* PC：ヒーローを画面いっぱいに表示し、開いた直後はタイトル欄だけが見えるように
   （次セクションが顔を出さない。sticky ヘッダー64px を差し引いて上下中央寄せ） */
@media (min-width: 601px) {
  .hero {
    min-height: calc(100vh - 64px);
    display: flex; flex-direction: column; justify-content: center;
    padding-top: 32px; padding-bottom: 56px;
  }
  .hero h1 { font-size: 54px; margin-bottom: 26px; }
  .hero-sub { font-size: 19px; margin-bottom: 24px; }
}

/* ========== CTA band ========== */
.cta-band {
  background: linear-gradient(135deg, var(--blue) 0%, var(--blue-bright) 100%);
  color: #fff; text-align: center; border-radius: var(--radius-lg);
  padding: 44px 24px; box-shadow: var(--shadow-lg);
}
.cta-band h2 { font-size: 26px; font-weight: 900; margin: 0 0 10px; }
.cta-band p { margin: 0 0 24px; opacity: .92; font-size: 15px; }
.cta-band .btn-primary {
  background: #fff; color: var(--blue); box-shadow: 0 8px 22px rgba(0,0,0,0.18);
}
.cta-band .btn-primary:hover { background: #f4f9ff; }

/* ========== Value（2つの価値） ========== */
.value { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.value-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.value-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 30px; box-shadow: var(--shadow); position: relative; overflow: hidden;
}
.value-card::before {
  content: ""; position: absolute; left: 0; top: 0; width: 100%; height: 5px;
  background: linear-gradient(90deg, var(--emerald), var(--emerald-soft));
}
.value-card.is-blue::before { background: linear-gradient(90deg, var(--blue), var(--blue-bright)); }
.value-kicker {
  font-family: var(--font-en); font-size: 12px; letter-spacing: 0.2em; font-weight: 800;
  color: var(--emerald); text-transform: uppercase;
}
.value-card.is-blue .value-kicker { color: var(--blue); }
.value-card h3 { font-size: 20px; font-weight: 800; margin: 8px 0 6px; line-height: 1.5; }
.value-lead { color: var(--ink-muted); font-size: 14px; margin: 0 0 20px; }
.value-flow { display: flex; flex-direction: column; gap: 12px; }
.value-step {
  display: flex; align-items: center; justify-content: center; gap: 14px;
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 15px 18px;
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background .16s ease;
}
.value-step:hover {
  transform: translateY(-3px);
  background: #fff; border-color: var(--emerald);
  box-shadow: 0 10px 22px rgba(15,163,124,.16);
}
.value-card.is-blue .value-step:hover { border-color: var(--blue); box-shadow: 0 10px 22px rgba(43,108,176,.16); }
.value-step .st-main { min-width: 0; display: flex; flex-direction: column; gap: 4px; text-align: center; }
.value-step .st-title { font-weight: 800; font-size: 16.5px; line-height: 1.45; }
.value-step .st-sub { font-size: 12.5px; color: var(--ink-dim); line-height: 1.6; }
.value-arrow { text-align: center; color: var(--emerald); font-size: 14px; line-height: 0; margin: -4px 0; }
.value-card.is-blue .value-arrow { color: var(--blue); }
.value-tail { margin: 18px 0 0; font-size: 13px; color: var(--ink-muted); font-weight: 700; text-align: center; }
/* 価値カード内の実アプリ・スクショ（PCブラウザ風フレーム） */
.value-shot { margin-top: 24px; display: flex; justify-content: center; }
.pc {
  width: 100%; max-width: 470px; border-radius: 12px; overflow: hidden;
  background: #fff; border: 1px solid var(--line);
  box-shadow: 0 16px 38px rgba(20,15,5,.18), 0 3px 10px rgba(20,15,5,.08);
}
.pc-bar {
  display: flex; align-items: center; gap: 6px;
  padding: 9px 12px; background: linear-gradient(180deg, #fbfaf6, var(--bg-soft));
  border-bottom: 1px solid var(--line);
}
.pc-bar .d { width: 9px; height: 9px; border-radius: 50%; background: #d9d5c8; }
.pc-bar .d:nth-child(1) { background: #ff5f57; }
.pc-bar .d:nth-child(2) { background: #febc2e; }
.pc-bar .d:nth-child(3) { background: #28c840; }
.pc-url {
  margin-left: 8px; flex: 1; max-width: 210px;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 3px 10px; font-size: 10px; color: var(--ink-muted);
  font-family: var(--font-en); letter-spacing: 0.04em; text-align: center;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.pc-screen { line-height: 0; background: #fff; }
.pc-screen img { width: 100%; display: block; }

/* ========== Live Demo ========== */
.demo-stage {
  display: grid; grid-template-columns: 1fr 1.35fr; gap: 36px; align-items: center;
}
.demo-copy h3 { font-size: 22px; font-weight: 800; margin: 0 0 14px; }
.demo-feat { list-style: none; padding: 0; margin: 0 0 26px; }
.demo-feat li {
  position: relative; padding-left: 30px; margin-bottom: 12px; color: var(--ink-muted);
  font-size: 15px;
}
.demo-feat li::before {
  content: "✓"; position: absolute; left: 0; top: 0;
  width: 20px; height: 20px; border-radius: 50%;
  background: rgba(15,163,124,0.14); color: var(--emerald);
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 900;
}
/* ブラウザ風モック（PC画面に見立てたフレーム） */
.device {
  background: #fff; border-radius: 16px; border: 1px solid var(--line);
  box-shadow: var(--shadow-lg); overflow: hidden;
}
.device-bar {
  display: flex; align-items: center; gap: 7px;
  padding: 12px 16px; background: linear-gradient(180deg, #fbfaf6, var(--bg-soft));
  border-bottom: 1px solid var(--line);
}
.device-bar .d { width: 11px; height: 11px; border-radius: 50%; background: #d9d5c8; }
.device-bar .d:nth-child(1) { background: #ff5f57; }
.device-bar .d:nth-child(2) { background: #febc2e; }
.device-bar .d:nth-child(3) { background: #28c840; }
.device-bar .url {
  margin-left: 12px; flex: 1; max-width: 280px;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 4px 14px; font-size: 12px; color: var(--ink-muted);
  font-family: var(--font-en); letter-spacing: 0.04em; text-align: center;
}
.device-body { padding: 22px; }

/* Live Demo：PC操作の自動再生動画 */
.demo-device {
  border-radius: 14px;
  box-shadow: 0 22px 50px rgba(20,15,5,.20), 0 4px 14px rgba(20,15,5,.10);
}
.device-screen { background: #eef5f2; line-height: 0; }
.demo-video {
  width: 100%; display: block; aspect-ratio: 1074 / 660; object-fit: cover;
}
.q-meta {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 12px; color: var(--ink-dim); margin-bottom: 12px;
}
.q-chip {
  background: rgba(43,108,176,0.10); color: var(--blue); font-weight: 700;
  padding: 3px 10px; border-radius: 999px; letter-spacing: 0.04em;
}
.q-text { font-size: 16px; font-weight: 700; line-height: 1.7; margin: 0 0 16px; }
.q-choices { display: flex; flex-direction: column; gap: 10px; }
.q-choice {
  border: 1.5px solid var(--line); border-radius: var(--radius); padding: 12px 14px;
  font-size: 14px; background: #fff; display: flex; gap: 10px; align-items: flex-start;
}
.q-choice .mk {
  flex: 0 0 22px; width: 22px; height: 22px; border-radius: 50%;
  border: 1.5px solid var(--line); display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 800; color: var(--ink-dim);
}
.q-choice.correct { border-color: var(--emerald); background: rgba(15,163,124,0.07); }
.q-choice.correct .mk { background: var(--emerald); border-color: var(--emerald); color: #fff; }
.q-explain {
  margin-top: 16px; padding: 14px; border-radius: var(--radius);
  background: var(--bg-soft); border-left: 3px solid var(--emerald);
  font-size: 13px; color: var(--ink-muted); line-height: 1.75;
}
.q-explain b { color: var(--emerald); }

/* ========== Voices (ユーザーの声) ========== */
.voices { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
/* Xboost風：左へ流れ、右から出てくる無限マーキー */
.voice-marquee {
  overflow: hidden;
  -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 7%, #000 93%, transparent 100%);
          mask-image: linear-gradient(90deg, transparent 0, #000 7%, #000 93%, transparent 100%);
}
.voice-track {
  display: flex; align-items: flex-start; width: max-content;
  animation: voice-scroll 48s linear infinite;
  will-change: transform;
}
@keyframes voice-scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}
/* 横長の合格報告スクショに合わせたカード（縦長→横長へ刷新） */
.voice-card {
  flex: 0 0 330px; width: 330px; margin-right: 20px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 10px; box-shadow: var(--shadow);
}
/* 画像はトリミングせず全体を表示（チャット本文を切らない） */
.voice-shot {
  border-radius: var(--radius); overflow: hidden; background: var(--bg-soft);
  line-height: 0;
}
.voice-shot img { width: 100%; height: auto; display: block; }
.voice-placeholder {
  text-align: center; color: var(--ink-dim); font-size: 13px; padding: 20px; line-height: 1.7;
}
.voice-cap { padding: 12px 8px 6px; font-size: 13px; color: var(--ink-muted); }
.voice-cap b { color: var(--ink); }

/* ========== Developer proof (開発者の合格実績) ========== */
.proof { background: linear-gradient(180deg, #fff 0%, var(--bg-soft) 100%); }
.proof-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); overflow: hidden;
  display: grid; grid-template-columns: 0.85fr 1.15fr;
}
.proof-imgs { background: var(--bg-soft); padding: 26px; display: flex; align-items: center; justify-content: center; }
.proof-cert {
  border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-lg); background: #fff; max-width: 380px; width: 100%;
}
.proof-cert img { width: 100%; display: block; }
.proof-body { padding: 34px; }
.proof-body h3 { font-size: 22px; font-weight: 800; margin: 0 0 8px; }
.proof-author { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.proof-avatar {
  width: 56px; height: 56px; border-radius: 50%; overflow: hidden;
  border: 2px solid #fff; box-shadow: var(--shadow); flex: 0 0 56px; background: var(--bg-soft);
}
.proof-avatar img { width: 100%; height: 100%; object-fit: cover; }
.proof-author .pa-name { font-weight: 800; }
.proof-author .pa-handle { font-size: 13px; color: var(--ink-dim); }
.proof-body p { font-size: 15px; color: var(--ink-muted); margin: 0 0 16px; }
.proof-stats { display: flex; gap: 14px; flex-wrap: wrap; margin: 20px 0 4px; }
.proof-stat {
  flex: 1; min-width: 120px; background: var(--bg-soft);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; text-align: center;
}
.proof-stat .v { font-size: 24px; font-weight: 900; color: var(--emerald); font-family: var(--font-en); }
.proof-stat .l { font-size: 12px; color: var(--ink-dim); }
.proof-disclaimer { font-size: 12px; color: var(--ink-dim); margin-top: 14px; }
.proof-social { display: flex; align-items: center; gap: 12px; margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--line); }
.proof-social .ps-label { font-size: 12px; color: var(--ink-dim); font-weight: 700; }
.social-link {
  width: 40px; height: 40px; border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; transition: transform .12s ease, box-shadow .12s ease;
}
.social-link:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.social-link svg { width: 20px; height: 20px; fill: currentColor; }
.social-ig { background: radial-gradient(circle at 30% 107%, #fdf497 0%, #fd5949 45%, #d6249f 60%, #285AEB 90%); }
.social-yt { background: #ff0000; }
.social-note { background: #41c9b4; }

/* ========== Popular articles（独自カード：画像＋タイトル＋説明 / xboost風） ========== */
.art-list {
  display: flex; flex-direction: column; gap: 12px;
  max-width: 820px; margin: 0 auto;
}
.art-card {
  display: flex; flex-direction: row; align-items: stretch;
  text-decoration: none;
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease;
}
.art-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--emerald-soft); }
.art-thumb { position: relative; flex: 0 0 188px; overflow: hidden; background: var(--bg-soft); }
.art-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .35s ease; }
.art-card:hover .art-thumb img { transform: scale(1.04); }
.art-body { display: flex; flex-direction: column; justify-content: center; gap: 6px; padding: 13px 18px; flex: 1; min-width: 0; }
.art-tag {
  align-self: flex-start;
  font-size: 10px; font-weight: 700; letter-spacing: .04em;
  color: var(--emerald);
  background: rgba(15,163,124,.10);
  border-radius: 999px; padding: 3px 10px;
}
.art-title {
  margin: 0; font-size: 15px; font-weight: 700; line-height: 1.45; color: var(--ink);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.art-desc {
  margin: 0; font-size: 12.5px; line-height: 1.6; color: var(--ink-muted);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}

.art-all { text-align: center; margin-top: 30px; }

/* ========== Footer ========== */
.site-footer {
  background: #1a1a1a; color: #cfcabd; padding: 48px 0 36px; font-size: 14px;
}
.site-footer .wrap { display: flex; flex-direction: column; align-items: center; gap: 18px; text-align: center; }
.footer-cta { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }
.footer-links a { color: #cfcabd; text-decoration: none; margin: 0 8px; }
.footer-links a:hover { color: #fff; text-decoration: underline; }
.footer-fine { font-size: 12px; color: #8a857a; line-height: 1.7; }

/* ========== Responsive ========== */
@media (max-width: 860px) {
  .demo-stage { grid-template-columns: 1fr; gap: 28px; }
  .proof-card { grid-template-columns: 1fr; }
  .art-grid { grid-template-columns: 1fr; }
  .value-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  /* スマホ：横並びを維持しつつ画像を小さく・カードを低く（文字の被り防止） */
  .art-card { align-items: stretch; }
  .art-thumb { flex: 0 0 104px; }
  .art-body { padding: 9px 12px; gap: 4px; }
  .art-tag { font-size: 9.5px; padding: 2px 8px; }
  .art-title { font-size: 12.5px; line-height: 1.4; -webkit-line-clamp: 2; }
  .art-desc { font-size: 11px; line-height: 1.55; -webkit-line-clamp: 2; }
}
@media (max-width: 600px) {
  body { font-size: 15px; }
  .section { padding: 52px 0; }
  /* スマホ：ヒーローを画面ぴったりに収め（次セクションが覗かない）、内容を上下中央寄せ＝タイトルが下がる */
  .hero {
    position: relative; overflow: hidden;
    padding: 24px 0 32px;
    min-height: calc(100vh - 64px);
    min-height: calc(100svh - 64px);
    display: flex; flex-direction: column; justify-content: center;
  }
  /* スマホ：背景にゆっくり漂うオーロラ風グロー（デザインアニメーション） */
  .hero::before {
    content: ""; position: absolute; left: -20%; right: -20%; top: -10%; height: 70%;
    background: radial-gradient(55% 60% at 50% 0%, rgba(45,212,168,0.30), transparent 70%);
    filter: blur(6px); pointer-events: none; z-index: 0;
    animation: heroAura 9s ease-in-out infinite alternate;
  }
  .hero .wrap { position: relative; z-index: 1; }
  /* スマホ：最新版バッジ（気持ち大きめ＋下に余白） */
  .hero-badge { padding: 7px 16px; font-size: 12px; gap: 7px; margin-bottom: 30px; }
  .hero-badge .dot { width: 8px; height: 8px; }
  .badge-new { font-size: 10px; padding: 3px 7px; }
  .hero h1 { font-size: 30px; line-height: 1.45; margin-bottom: 30px; word-break: keep-all; overflow-wrap: anywhere; }
  .hero-h1-sub { margin-top: 16px; font-size: 17px; }
  .hero-h1-sub .sp-br { display: inline; }
  /* スマホ：タイトル下の説明文（スライドで学び…）は非表示 */
  .hero-sub { display: none; }
  .hero-note { margin-top: 26px; }
  .section-title { font-size: 23px; }
  .brand-name { font-size: 17px; }
  .btn-header { padding: 9px 16px; font-size: 13px; }
  /* スマホでは「学習支援」ボタンとヘッダーの「アプリを開く」を隠し、
     三本線（ハンバーガー）のみ表示。メニュー内に「アプリ」を出す */
  .nav-learn-btn { display: none; }
  .nav-header-app { display: none; }
  .nav-learn-app { display: flex; }
  .nav-burger {
    display: inline-flex; flex-direction: column; justify-content: center; align-items: center;
    gap: 5px; width: 42px; height: 38px; padding: 0;
    background: #fff; border: 1.5px solid var(--emerald); border-radius: 12px;
    cursor: pointer;
  }
  .nav-burger span {
    width: 20px; height: 2px; border-radius: 2px; background: var(--emerald);
    transition: transform .2s ease, opacity .2s ease;
  }
  /* 開いている間は×印に変形 */
  .nav-learn-check:checked ~ .nav-learn .nav-burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-learn-check:checked ~ .nav-learn .nav-burger span:nth-child(2) { opacity: 0; }
  .nav-learn-check:checked ~ .nav-learn .nav-burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  /* メニューはハンバーガー基準で右寄せに表示 */
  .nav-learn-menu { left: auto; right: 0; min-width: 196px; }
  /* スマホはホバーで開かない（タップ＝チェックのみ）。誤作動防止 */
  .nav-learn:hover .nav-learn-menu { opacity: 0; visibility: hidden; transform: translateY(-8px); }
  .nav-learn-check:checked ~ .nav-learn .nav-learn-menu { opacity: 1; visibility: visible; transform: translateY(0); }
  .hero-cta { flex-direction: column; align-items: center; gap: 16px; margin-top: 4px; }
  .hero-cta .btn { width: auto; }
  .hero-cta .btn-lg { font-size: 16px; padding: 14px 28px; }

  /* Why G模試：タイトルを画面幅に応じて縮め、1行に収める
     （余白を引いた使用可能幅から逆算し、はみ出さないようにする。約20文字想定） */
  #value .section-title { font-size: min(23px, calc((100vw - 48px) / 20)); white-space: nowrap; }

  /* Why G模試：スマホでは要素を絞ってコンパクトに（カードを画面幅に収める） */
  #value .section-eyebrow { font-size: 15px; }     /* 「Why G模試」を少し大きく */
  #value .section-sub { display: none; }            /* 「参考書・ノート…」説明文を非表示 */
  #value .value-card { padding: 22px 20px; }        /* カードの余白を詰める */
  #value .value-step .st-sub { display: none; }     /* 各ステップのグレー説明を非表示 */
  #value .value-step { padding: 11px 14px; }        /* ステップ枠を小さく */
  /* 「→ …」の一文を1行に収める（カード内幅から逆算。約24文字想定） */
  #value .value-tail { white-space: nowrap; font-size: min(13px, calc((100vw - 96px) / 24)); }

  /* Live Demo：見出し・説明リストを省き、動画を主役（先頭）に */
  .demo-copy h3, .demo-feat { display: none; }
  .demo-stage { display: flex; flex-direction: column; gap: 20px; }
  .demo-device { order: -1; }
  .demo-copy { text-align: center; }

  /* Proof：本文の左右余白を詰めたうえで、自己紹介の見出しを1行に収める
     （カードの余白＝.wrap20px＋本文20px を差し引いた幅から逆算。約18文字想定） */
  .proof-body { padding: 22px 20px; }
  .proof-body h3 { font-size: min(22px, calc((100vw - 88px) / 18)); white-space: nowrap; }
  /* 合格証書の枠を小さく（高さを抑え）、本文も少し縮めてカードを画面内に収める */
  .proof-imgs { padding: 16px; }
  .proof-cert { max-width: 230px; margin: 0 auto; }
  .proof-body p { font-size: 13.5px; line-height: 1.8; margin: 0 0 12px; }
  .proof-author { margin-bottom: 14px; }
  .proof-stats { gap: 10px; margin: 16px 0 4px; }
  .proof-stat { padding: 11px 8px; min-width: 92px; }
  .proof-stat .v { font-size: 20px; }

  /* Voices：スマホでは次のカードが少し覗く幅に */
  .voice-card { flex-basis: 280px; width: 280px; }
}