@charset "UTF-8";
/* =========================================================
   STELLAR | AIの歴史と未来 (history-of-ai)
   既存トンマナ(ライトブルー #ABCFDF / Zen Maru Gothic / Arima)を
   踏襲しつつ、ガラスモーフィズム・グラデーション・光の演出で
   「未来感 / テクノロジー / ワクワク」を加えるページ専用CSS
   ========================================================= */

:root {
    --ai-blue: #4a9fd4;
    --ai-blue-deep: #12325c;
    --ai-navy: #0b1f3a;
    --ai-cyan: #8ad4ef;
    --ai-ink: #33475b;
    --ai-glass: rgba(255, 255, 255, 0.62);
    --ai-glass-line: rgba(255, 255, 255, 0.85);
    --ai-shadow: 0 20px 50px -20px rgba(18, 50, 92, 0.45);
    --ai-radius: 22px;
}

/* ---- 全体トーン ---- */
.ai-history {
    overflow-x: hidden;
}

/* 背景動画（style_top.css を読み込まないため本ページ用に定義） */
.ai-history #bg-video {
    position: fixed;
    top: 0;
    left: 0;
    min-width: 100%;
    min-height: 100%;
    object-fit: cover;
    z-index: -1;
    pointer-events: none;
    opacity: 0.6;
    transform: none;
}
@media screen and (max-aspect-ratio: 3/4) {
    .ai-history #bg-video {
        transform: rotate(90deg);
        transform-origin: center center;
        width: 100vh;
        height: 100vw;
        top: 50%;
        left: 50%;
        min-width: unset;
        min-height: unset;
        translate: -50% -50%;
        object-fit: cover;
    }
}

/* style_page.css の #page #main (2ID) を上書きしてフルブリード化 */
#page.ai-history #main {
    width: 100%;
    max-width: none;
    margin: 0;
    padding: 0;
}

/* マウス追従グロー */
.ai-cursor-glow {
    position: fixed;
    top: 0;
    left: 0;
    width: 480px;
    height: 480px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(138, 212, 239, 0.35) 0%, rgba(138, 212, 239, 0) 65%);
    transform: translate3d(-50%, -50%, 0);
    pointer-events: none;
    z-index: 5;
    opacity: 0;
    transition: opacity 0.6s ease;
    mix-blend-mode: screen;
}

/* 共通：セクション見出し */
.ai-sec-head {
    text-align: center;
    margin-bottom: 3.5rem;
    padding: 0 1rem;
}
.ai-sec-head .en {
    display: block;
    font-family: "Arima", system-ui;
    font-weight: 300;
    font-size: clamp(2.4rem, 6vw, 4rem);
    line-height: 1;
    color: #fff;
    letter-spacing: 3px;
    text-shadow: 0 8px 30px rgba(11, 31, 58, 0.35);
}
.ai-sec-head .ja {
    display: inline-block;
    margin-top: 1rem;
    font-size: clamp(1rem, 2.4vw, 1.35rem);
    font-weight: 700;
    color: var(--ai-blue-deep);
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(6px);
    backdrop-filter: blur(6px);
    padding: 0.35rem 1.4rem;
    border-radius: 999px;
    box-shadow: var(--ai-shadow);
}
.ai-sec-lead {
    max-width: 720px;
    margin: 1.6rem auto 0;
    text-align: center;
    font-size: 1.02rem;
    color: var(--ai-ink);
    line-height: 2;
}

/* =========================================================
   Reveal 基本アニメーション
   ========================================================= */
[data-reveal] {
    opacity: 0;
    transform: translateY(38px);
    transition: opacity 0.9s cubic-bezier(.22,.61,.36,1),
                transform 0.9s cubic-bezier(.22,.61,.36,1);
    will-change: opacity, transform;
}
[data-reveal].is-visible {
    opacity: 1;
    transform: none;
}
[data-reveal="depth"] {
    transform: perspective(1200px) translateZ(-320px) translateY(60px) rotateX(12deg);
    opacity: 0;
    transition: opacity 1s ease, transform 1.1s cubic-bezier(.16,.84,.28,1);
}
[data-reveal="depth"].is-visible {
    transform: perspective(1200px) translateZ(0) translateY(0) rotateX(0);
    opacity: 1;
}
[data-reveal-delay="1"] { transition-delay: .08s; }
[data-reveal-delay="2"] { transition-delay: .16s; }
[data-reveal-delay="3"] { transition-delay: .24s; }
[data-reveal-delay="4"] { transition-delay: .32s; }
[data-reveal-delay="5"] { transition-delay: .40s; }

@media (prefers-reduced-motion: reduce) {
    [data-reveal],
    [data-reveal="depth"] {
        opacity: 1 !important;
        transform: none !important;
        transition: none !important;
    }
}

/* =========================================================
   HERO
   ========================================================= */
.ai-hero {
    position: relative;
    min-height: 100svh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 8rem 1.5rem 4rem;
    overflow: hidden;
}
.ai-hero__particles {
    /* 全ページ共通の背景パーティクル(bg-particles.js)に統一したため非表示 */
    display: none;
}
.ai-hero__inner {
    position: relative;
    z-index: 3;
    max-width: 960px;
}
.ai-hero__eyebrow {
    font-family: "Arima", system-ui;
    font-weight: 300;
    letter-spacing: 6px;
    font-size: clamp(0.8rem, 2vw, 1.05rem);
    color: var(--ai-cyan);
    text-transform: uppercase;
    margin-bottom: 1.4rem;
    opacity: 0;
    animation: ai-fade-up 1s ease .2s forwards;
}
.ai-hero__title {
    font-size: clamp(2.6rem, 8.5vw, 6rem);
    font-weight: 900;
    line-height: 1.12;
    color: #fff;
    letter-spacing: 2px;
    text-shadow: 0 14px 44px rgba(11, 31, 58, 0.5);
    margin: 0;
    opacity: 0;
    animation: ai-fade-up 1.1s ease .35s forwards;
}
.ai-hero__title .grad {
    background: linear-gradient(100deg, #ffffff 0%, var(--ai-cyan) 55%, #cfeeff 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.ai-hero__en {
    display: block;
    font-family: "Arima", system-ui;
    font-weight: 300;
    font-size: clamp(0.9rem, 2.6vw, 1.4rem);
    letter-spacing: 5px;
    color: rgba(255, 255, 255, 0.82);
    margin-top: 1.1rem;
    opacity: 0;
    animation: ai-fade-up 1.1s ease .5s forwards;
}
.ai-hero__sub {
    margin-top: 2rem;
    font-size: clamp(1rem, 2.6vw, 1.4rem);
    font-weight: 500;
    line-height: 1.9;
    color: #fff;
    text-shadow: 0 6px 24px rgba(11, 31, 58, 0.4);
    opacity: 0;
    animation: ai-fade-up 1.1s ease .65s forwards;
}
.ai-hero__scroll {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    color: #fff;
    text-align: center;
    opacity: 0;
    animation: ai-fade-up 1s ease 1s forwards;
}
.ai-hero__scroll .en {
    font-family: "Arima", system-ui;
    font-size: 0.8rem;
    letter-spacing: 3px;
    display: block;
    margin-bottom: .4rem;
}
.ai-hero__scroll .line {
    display: inline-block;
    width: 1px;
    height: 56px;
    background: linear-gradient(to bottom, #fff, transparent);
    animation: ai-scroll-line 1.8s ease-in-out infinite;
    transform-origin: top;
}
@keyframes ai-scroll-line {
    0%   { transform: scaleY(0); opacity: 0; }
    40%  { transform: scaleY(1); opacity: 1; }
    100% { transform: scaleY(1) translateY(30px); opacity: 0; }
}
@keyframes ai-fade-up {
    from { opacity: 0; transform: translateY(28px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ステータス（数字カウントアップ） */
.ai-stats {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-top: 3rem;
    position: relative;
    z-index: 3;
}
.ai-stats__item {
    background: rgba(255, 255, 255, 0.14);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.28);
    border-radius: 18px;
    padding: 1rem 1.6rem;
    min-width: 148px;
}
.ai-stats__num {
    font-family: "Arima", system-ui;
    font-weight: 400;
    font-size: 2.4rem;
    line-height: 1;
    color: #fff;
}
.ai-stats__num .suffix { font-size: 1.2rem; }
.ai-stats__label {
    display: block;
    margin-top: .4rem;
    font-size: .82rem;
    color: rgba(255, 255, 255, 0.85);
}

/* =========================================================
   共通 ラッパー
   ========================================================= */
.ai-section {
    position: relative;
    z-index: 2;
    padding: 6rem 1.2rem;
    max-width: 1180px;
    margin: 0 auto;
}
.ai-section--tight { padding-top: 2rem; }

/* =========================================================
   Section1 : TIMELINE
   ========================================================= */
.ai-timeline {
    position: relative;
    max-width: 920px;
    margin: 0 auto;
    padding-left: 8px;
}
.ai-timeline__track {
    position: absolute;
    top: 8px;
    bottom: 8px;
    left: 26px;
    width: 3px;
    background: rgba(255, 255, 255, 0.45);
    border-radius: 3px;
    overflow: hidden;
}
.ai-timeline__progress {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0;
    background: linear-gradient(to bottom, var(--ai-cyan), var(--ai-blue));
    box-shadow: 0 0 16px rgba(138, 212, 239, 0.9);
}
.ai-tl-item {
    position: relative;
    padding: 0 0 3.2rem 68px;
    min-height: 60px;
}
.ai-tl-item:last-child { padding-bottom: 0; }
.ai-tl-item__dot {
    position: absolute;
    left: 16px;
    top: 4px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: #fff;
    border: 3px solid var(--ai-blue);
    box-shadow: 0 0 0 6px rgba(255, 255, 255, 0.35);
    transition: transform .5s ease, box-shadow .5s ease;
}
.ai-tl-item.is-visible .ai-tl-item__dot {
    transform: scale(1.15);
    box-shadow: 0 0 0 8px rgba(138, 212, 239, 0.5), 0 0 20px rgba(74, 159, 212, 0.7);
}
.ai-tl-item__year {
    font-family: "Arima", system-ui;
    font-weight: 400;
    font-size: 1.5rem;
    color: #fff;
    letter-spacing: 1px;
    line-height: 1.2;
}
.ai-tl-item__card {
    margin-top: .7rem;
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border: 1px solid var(--ai-glass-line);
    border-radius: var(--ai-radius);
    padding: 1.3rem 1.5rem;
    box-shadow: var(--ai-shadow);
}
.ai-tl-item__card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--ai-blue-deep);
    margin: 0 0 .4rem;
}
.ai-tl-item__card p {
    margin: 0;
    font-size: .95rem;
    color: var(--ai-ink);
    line-height: 1.9;
}

/* =========================================================
   Section2 : CAPABILITIES (glass cards grid)
   ========================================================= */
.ai-cap-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 1.1rem;
}
.ai-cap {
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border: 1px solid var(--ai-glass-line);
    border-radius: var(--ai-radius);
    padding: 1.6rem 1.2rem;
    text-align: center;
    box-shadow: var(--ai-shadow);
    transition: transform .45s cubic-bezier(.2,.7,.3,1), box-shadow .45s ease;
    position: relative;
    overflow: hidden;
}
.ai-cap::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(140deg, rgba(138,212,239,.35), rgba(255,255,255,0) 55%);
    opacity: 0;
    transition: opacity .45s ease;
}
.ai-cap:hover {
    transform: translateY(-10px);
    box-shadow: 0 30px 60px -22px rgba(18, 50, 92, 0.6);
}
.ai-cap:hover::before { opacity: 1; }
.ai-cap__icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 14px;
    background: linear-gradient(135deg, var(--ai-blue), var(--ai-cyan));
    color: #fff;
    position: relative;
    z-index: 1;
}
.ai-cap__icon svg { width: 26px; height: 26px; stroke-width: 1.8; }
.ai-cap__label {
    position: relative;
    z-index: 1;
    font-weight: 700;
    font-size: 1rem;
    color: var(--ai-blue-deep);
}

/* =========================================================
   Section3 : JOBS 対比 (dark drama)
   ========================================================= */
.ai-jobs {
    position: relative;
    z-index: 2;
    background: linear-gradient(160deg, var(--ai-navy), var(--ai-blue-deep));
    border-radius: 32px;
    max-width: 1180px;
    margin: 0 auto;
    padding: 4.5rem 1.5rem 4rem;
    overflow: hidden;
    box-shadow: 0 40px 90px -40px rgba(11, 31, 58, 0.8);
}
.ai-jobs::after {
    content: "";
    position: absolute;
    top: -30%;
    left: 50%;
    width: 620px;
    height: 620px;
    transform: translateX(-50%);
    background: radial-gradient(circle, rgba(74,159,212,.4), transparent 62%);
    pointer-events: none;
}
.ai-jobs__grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.2rem;
    max-width: 900px;
    margin: 0 auto;
}
.ai-jobs__col {
    border-radius: var(--ai-radius);
    padding: 2.2rem 1.8rem;
    text-align: center;
}
.ai-jobs__col--con {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.14);
}
.ai-jobs__col--pro {
    background: linear-gradient(135deg, rgba(74,159,212,.35), rgba(138,212,239,.18));
    border: 1px solid rgba(138, 212, 239, 0.5);
}
.ai-jobs__tag {
    font-family: "Arima", system-ui;
    letter-spacing: 3px;
    font-size: .8rem;
    text-transform: uppercase;
    color: var(--ai-cyan);
}
.ai-jobs__col--con .ai-jobs__tag { color: rgba(255,255,255,.55); }
.ai-jobs__phrase {
    margin: .8rem 0 0;
    font-size: clamp(1.25rem, 3.6vw, 1.9rem);
    font-weight: 700;
    line-height: 1.5;
    color: #fff;
}
.ai-jobs__vs {
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: "Arima", system-ui;
    font-size: 1.4rem;
    color: var(--ai-cyan);
    letter-spacing: 2px;
}
.ai-jobs__msg {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 760px;
    margin: 3rem auto 0;
    color: #fff;
}
.ai-jobs__msg strong {
    display: block;
    font-size: clamp(1.3rem, 4vw, 2.1rem);
    font-weight: 900;
    line-height: 1.6;
    background: linear-gradient(100deg, #fff, var(--ai-cyan));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.ai-jobs__msg p {
    margin-top: 1rem;
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.82);
    line-height: 2;
}
@media (min-width: 768px) {
    .ai-jobs__grid {
        grid-template-columns: 1fr auto 1fr;
        align-items: stretch;
    }
    .ai-jobs__col { display: flex; flex-direction: column; justify-content: center; }
}

/* =========================================================
   Section4 : FUTURE (depth cards)
   ========================================================= */
.ai-future-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
    gap: 1.2rem;
    perspective: 1400px;
}
.ai-future-card {
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border: 1px solid var(--ai-glass-line);
    border-radius: var(--ai-radius);
    padding: 1.8rem 1.5rem;
    box-shadow: var(--ai-shadow);
    transition: transform .45s cubic-bezier(.2,.7,.3,1), box-shadow .45s ease;
}
.ai-future-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 34px 66px -24px rgba(18, 50, 92, 0.6);
}
.ai-future-card__icon {
    width: 44px; height: 44px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 12px;
    background: rgba(74, 159, 212, 0.14);
    color: var(--ai-blue);
    margin-bottom: 1rem;
}
.ai-future-card__icon svg { width: 24px; height: 24px; stroke-width: 1.8; }
.ai-future-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--ai-blue-deep);
    margin: 0 0 .5rem;
}
.ai-future-card p {
    margin: 0;
    font-size: .9rem;
    color: var(--ai-ink);
    line-height: 1.85;
}

/* =========================================================
   Section5 : STELLAR SERVICES
   ========================================================= */
.ai-serv-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.1rem;
    margin-bottom: 3rem;
}
.ai-serv {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border: 1px solid var(--ai-glass-line);
    border-radius: var(--ai-radius);
    padding: 1.4rem 1.4rem;
    box-shadow: var(--ai-shadow);
    transition: transform .4s ease;
}
.ai-serv:hover { transform: translateY(-6px); }
.ai-serv__icon {
    flex: 0 0 auto;
    width: 44px; height: 44px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--ai-blue), var(--ai-cyan));
    color: #fff;
}
.ai-serv__icon svg { width: 24px; height: 24px; stroke-width: 1.8; }
.ai-serv__body h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ai-blue-deep);
    margin: 0 0 .3rem;
}
.ai-serv__body p {
    margin: 0;
    font-size: .88rem;
    color: var(--ai-ink);
    line-height: 1.8;
}

/* CTA ボタン（既存 .btn-l を踏襲しつつ光彩を付与） */
.ai-cta {
    text-align: center;
}
.ai-cta a {
    display: inline-block;
    color: #fff;
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: 1px;
    background: linear-gradient(120deg, var(--ai-blue-deep), var(--ai-blue));
    border-radius: 999px;
    padding: 16px 46px;
    text-decoration: none;
    box-shadow: 0 18px 40px -14px rgba(18, 50, 92, 0.75);
    transition: all .45s cubic-bezier(.2,.7,.3,1);
    position: relative;
}
.ai-cta a:hover {
    padding: 16px 60px;
    box-shadow: 0 24px 54px -14px rgba(74, 159, 212, 0.9);
}
.ai-cta a .arrow { margin-left: .5rem; }

/* =========================================================
   Section6 : FINAL MESSAGE (future city)
   ========================================================= */
.ai-final {
    position: relative;
    min-height: 92svh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    background: linear-gradient(180deg, var(--ai-blue-deep) 0%, var(--ai-navy) 100%);
    margin-top: 5rem;
    padding: 6rem 1.5rem;
}
.ai-final__city {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
}
.ai-final__glow {
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 130%;
    height: 55%;
    transform: translateX(-50%);
    background: radial-gradient(ellipse at bottom, rgba(74,159,212,.5), transparent 68%);
    z-index: 1;
    pointer-events: none;
}
.ai-final__inner {
    position: relative;
    z-index: 3;
    max-width: 860px;
}
.ai-final__lead {
    font-size: clamp(1.7rem, 6vw, 3.6rem);
    font-weight: 900;
    line-height: 1.5;
    color: #fff;
    text-shadow: 0 14px 44px rgba(0,0,0,.5);
    margin: 0;
}
.ai-final__lead .grad {
    background: linear-gradient(100deg, #fff, var(--ai-cyan));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.ai-final__choice {
    margin: 2.4rem 0 2.8rem;
    font-size: clamp(1.1rem, 3.4vw, 1.7rem);
    font-weight: 700;
    color: rgba(255, 255, 255, 0.92);
    line-height: 2;
}
.ai-final__choice span {
    display: inline-block;
    border-bottom: 2px solid var(--ai-cyan);
    padding-bottom: 2px;
}

/* パンくず */
.ai-breadcrumb {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    max-width: 1180px;
    margin: 0 auto;
    padding: 5rem 1.6rem 0;
    font-size: .78rem;
    color: rgba(255, 255, 255, 0.9);
    z-index: 4;
}
@media (min-width: 768px) {
    .ai-breadcrumb { padding-top: 5.5rem; }
}
.ai-breadcrumb ol {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: .4rem;
    padding: 0;
    margin: 0;
}
.ai-breadcrumb a { color: #fff; text-decoration: none; opacity: .85; }
.ai-breadcrumb a:hover { opacity: 1; text-decoration: underline; }
.ai-breadcrumb li[aria-current] { font-weight: 700; }

/* FAQ */
.ai-faq {
    max-width: 820px;
    margin: 0 auto;
}
.ai-faq__item {
    background: var(--ai-glass);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border: 1px solid var(--ai-glass-line);
    border-radius: 18px;
    margin-bottom: 1rem;
    box-shadow: var(--ai-shadow);
    overflow: hidden;
}
.ai-faq__q {
    width: 100%;
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
    padding: 1.2rem 3rem 1.2rem 1.4rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--ai-blue-deep);
    position: relative;
    font-family: inherit;
}
.ai-faq__q::after {
    content: "";
    position: absolute;
    right: 1.4rem;
    top: 50%;
    width: 11px;
    height: 11px;
    border-right: 2px solid var(--ai-blue);
    border-bottom: 2px solid var(--ai-blue);
    transform: translateY(-70%) rotate(45deg);
    transition: transform .35s ease;
}
.ai-faq__item.is-open .ai-faq__q::after { transform: translateY(-30%) rotate(-135deg); }
.ai-faq__a {
    max-height: 0;
    overflow: hidden;
    transition: max-height .4s ease;
}
.ai-faq__a p {
    margin: 0;
    padding: 0 1.4rem 1.3rem;
    font-size: .92rem;
    color: var(--ai-ink);
    line-height: 1.9;
}

/* 下部の TOP 戻り */
.ai-backtop {
    text-align: center;
    padding: 3rem 1rem 4rem;
    position: relative;
    z-index: 2;
}
.ai-backtop a {
    display: inline-block;
    color: var(--ai-blue-deep);
    font-weight: 700;
    letter-spacing: 2px;
    text-decoration: none;
    background: var(--ai-glass);
    border: 1px solid var(--ai-glass-line);
    padding: 12px 40px;
    border-radius: 999px;
    transition: all .4s ease;
}
.ai-backtop a:hover { transform: translateY(-4px); box-shadow: var(--ai-shadow); }

/* =========================================================
   レスポンシブ微調整
   ========================================================= */
@media (min-width: 768px) {
    .ai-section { padding: 7rem 2rem; }
    .ai-cap-grid { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 480px) {
    .ai-stats__item { min-width: 120px; padding: .8rem 1rem; }
    .ai-stats__num { font-size: 2rem; }
}