/* ============================================================
   Investor AI — トップLP（コーポレート／明朝×硬派・動画背景）
   home.html 専用スタイル。base/legal とは独立（home.html は単独テンプレート）。
   ============================================================ */
:root{
  --paper:#f5f3ec; --paper-2:#efece1; --ink:#121d18; --ink-2:#33423c;
  --muted:#6f7d76; --line:#dcd7c8; --line-2:#cbc6b6;
  --green:#008b8b; --green-d:#006d6b; --green-ink:#0a4a45;
  --dark:#0c1512; --dark-2:#111e19; --dark-line:#26332d;
  --on-dark:#ece9dd; --on-dark-mut:#93a29a; --green-br:#1fb9a9;
  --maxw:1180px;
  --serif:"Hiragino Mincho ProN","Hiragino Mincho Pro","Yu Mincho","YuMincho","Noto Serif JP",Georgia,"Times New Roman",serif;
  --sans:-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Hiragino Sans","Noto Sans JP","Yu Gothic UI","Meiryo",sans-serif;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:var(--sans);color:var(--ink);background:var(--paper);line-height:1.9;font-size:16px;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
h1,h2,h3,h4,p,figure,blockquote,ul{margin:0}
button{font-family:inherit}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 26px}
.eyebrow{font-family:var(--mono);font-size:11px;font-weight:600;letter-spacing:.28em;text-transform:uppercase;color:var(--green-d);display:inline-flex;align-items:center;gap:12px}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;opacity:.7}
.eyebrow.jp::after{content:attr(data-jp);font-family:var(--sans);letter-spacing:.14em;color:var(--muted);font-size:11px}
h1,h2,h3{font-family:var(--serif);font-weight:600;letter-spacing:.01em;text-wrap:balance}
.sec-t{font-size:clamp(1.7rem,3.8vw,2.65rem);line-height:1.4;margin:20px 0 0}
.lead{color:var(--ink-2);font-size:16px;max-width:640px;margin:22px 0 0;line-height:2}
.num{font-variant-numeric:tabular-nums}
.center{text-align:center}
.center .eyebrow{justify-content:center}
.center .lead{margin-left:auto;margin-right:auto}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;font-family:var(--sans);font-weight:700;font-size:14px;letter-spacing:.06em;border-radius:3px;padding:15px 28px;border:1px solid transparent;cursor:pointer;transition:background .18s,color .18s,border-color .18s}
.btn-primary{background:var(--green);color:#fff}
.btn-primary:hover{background:var(--green-d)}
.btn-outline{background:transparent;color:var(--ink);border-color:var(--line-2)}
.btn-outline:hover{border-color:var(--ink);}
.btn-ondark{background:var(--green-br);color:#04211d}
.btn-ondark:hover{background:#fff;color:var(--dark)}
.btn-lg{padding:17px 34px;font-size:15px}

/* header */
.lp-header{position:sticky;top:0;z-index:60;background:transparent;backdrop-filter:saturate(180%) blur(2px);border-bottom:1px solid transparent;transition:background .25s,border-color .25s;color:var(--on-dark)}
.lp-header::before{content:"";position:absolute;inset:0;z-index:-1;pointer-events:none;transition:opacity .25s;
  background:linear-gradient(180deg,rgba(5,10,8,.66) 0%,rgba(5,10,8,.28) 60%,rgba(5,10,8,0) 100%)}
.lp-header.stuck{background:rgba(245,243,236,.9);backdrop-filter:saturate(180%) blur(10px);border-color:var(--line);color:var(--ink)}
.lp-header.stuck::before{opacity:0}
.nav{display:flex;align-items:center;justify-content:space-between;height:70px}
.brand{display:flex;align-items:baseline;gap:9px;font-family:var(--serif);font-size:20px;letter-spacing:.06em;color:inherit}
.brand .dot{width:7px;height:7px;border-radius:50%;background:var(--green-br);align-self:center}
.lp-header.stuck .brand .dot{background:var(--green)}
.brand b{font-weight:600}
.nav-links{display:flex;gap:30px}
.nav-links a{font-size:13px;letter-spacing:.08em;color:rgba(240,238,229,.94)}
.lp-header:not(.stuck) .brand,.lp-header:not(.stuck) .nav-links a{text-shadow:0 1px 12px rgba(0,0,0,.6)}
.lp-header.stuck .nav-links a{color:var(--ink-2)}
.nav-links a:hover{color:var(--green-br)}
.lp-header.stuck .nav-links a:hover{color:var(--green-d)}
.nav .btn{padding:11px 20px;font-size:13px}
/* hamburger */
.nav-toggle{display:none;width:42px;height:42px;margin-right:-9px;border:0;background:transparent;color:inherit;cursor:pointer;position:relative}
.nav-toggle span{position:absolute;left:10px;top:50%;width:22px;height:1.6px;margin-top:-1px;background:currentColor;transition:background .2s}
.nav-toggle span::before,.nav-toggle span::after{content:"";position:absolute;left:0;width:22px;height:1.6px;background:currentColor;transition:transform .26s}
.nav-toggle span::before{top:-7px}
.nav-toggle span::after{top:7px}
.lp-header.menu-open .nav-toggle span{background:transparent}
.lp-header.menu-open .nav-toggle span::before{transform:translateY(7px) rotate(45deg)}
.lp-header.menu-open .nav-toggle span::after{transform:translateY(-7px) rotate(-45deg)}
.lp-header:not(.stuck) .nav-toggle{filter:drop-shadow(0 1px 8px rgba(0,0,0,.55))}
.mobile-nav{display:none}
@media(max-width:880px){
  .nav-links{display:none}
  .nav > .btn{display:none}
  .nav-toggle{display:block}
  .mobile-nav{display:block;position:fixed;left:0;right:0;top:70px;z-index:55;background:var(--dark);border-top:1px solid var(--dark-line);padding:6px 26px 22px;opacity:0;visibility:hidden;transform:translateY(-10px);transition:opacity .25s,transform .25s,visibility .25s;box-shadow:0 26px 44px -22px rgba(0,0,0,.6)}
  .lp-header.menu-open .mobile-nav{opacity:1;visibility:visible;transform:none}
  .mobile-nav a:not(.btn){display:block;padding:15px 2px;color:var(--on-dark);font-size:15px;letter-spacing:.04em;border-bottom:1px solid var(--dark-line)}
  .mobile-nav a:not(.btn):hover{color:var(--green-br)}
  .mobile-nav .btn{display:flex;width:100%;margin-top:18px}
}

section{position:relative}
.band{padding:clamp(64px,8vw,116px) 0}
.band.paper2{background:var(--paper-2)}
.band.dark{background:var(--dark);color:var(--on-dark)}
.band.dark .eyebrow{color:var(--green-br)}
.band.dark .lead{color:var(--on-dark-mut)}
.rule{height:1px;background:var(--line);border:0;margin:0}

/* hero (video background, centered) */
.hero{position:relative;overflow:hidden;display:flex;align-items:center;text-align:center;color:var(--on-dark);
  min-height:clamp(600px,92vh,900px);padding:120px 0 100px;
  background:linear-gradient(135deg,#0a1512 0%,#0f231d 52%,#091714 100%)}
.hero-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:0}
.hero-scrim{position:absolute;inset:0;z-index:1;
  background:radial-gradient(130% 120% at 50% 40%,rgba(8,17,14,.20) 0%,rgba(8,17,14,.44) 60%,rgba(7,15,12,.60) 100%)}
.hero-scrim::after{content:"";position:absolute;inset:0;opacity:.5;
  background:radial-gradient(60% 50% at 50% 45%,rgba(0,139,139,.22),transparent 70%);animation:heroGlow 12s ease-in-out infinite}
@keyframes heroGlow{0%,100%{opacity:.35;transform:scale(1)}50%{opacity:.6;transform:scale(1.08)}}
.hero-inner{position:relative;z-index:2;max-width:820px;margin:0 auto}
.hero-flash{max-width:560px;margin:0 auto 4px}
.flash{border-radius:4px;padding:12px 16px;font-size:14px;font-weight:600;text-align:center;backdrop-filter:blur(4px)}
.flash--error{background:rgba(255,92,108,.18);border:1px solid rgba(255,120,132,.5);color:#ffdde1}
.flash--success{background:rgba(31,185,169,.18);border:1px solid rgba(31,185,169,.5);color:#d6fff8}
.hero .eyebrow{color:var(--green-br);justify-content:center;text-shadow:0 1px 14px rgba(6,12,10,.6)}
.hero h1{font-size:clamp(1.7rem,5.8vw,4.1rem);line-height:1.34;margin:22px 0 0;color:var(--on-dark);text-shadow:0 2px 24px rgba(6,12,10,.72),0 1px 3px rgba(6,12,10,.55)}
.hero h1 .g{color:var(--green-br)}
.hero h1 .ln2{white-space:nowrap}
@media(max-width:380px){.hero h1{font-size:1.5rem}}
.hero .lead{font-size:17px;max-width:560px;margin-left:auto;margin-right:auto;color:rgba(236,233,221,.95);text-shadow:0 1px 18px rgba(6,12,10,.75),0 1px 2px rgba(6,12,10,.5)}
.hero .signup{margin:34px auto 0;justify-content:center}
.hero .signup input{border-color:transparent;box-shadow:0 12px 30px -18px rgba(0,0,0,.6)}
.hero .form-note{color:rgba(236,233,221,.85);text-align:center;text-shadow:0 1px 14px rgba(6,12,10,.62)}
.hero .form-ok{max-width:500px;margin-left:auto;margin-right:auto;background:rgba(31,185,169,.14);border-color:rgba(31,185,169,.42);color:var(--on-dark)}
.trust{display:flex;flex-wrap:wrap;gap:10px 22px;margin-top:22px;color:rgba(236,233,221,.9);font-size:12.5px;letter-spacing:.04em;justify-content:center;text-shadow:0 1px 12px rgba(6,12,10,.6)}
.trust span{display:inline-flex;align-items:center;gap:8px}
.trust span::before{content:"";width:5px;height:5px;background:var(--green-br);border-radius:50%}
@media(prefers-reduced-motion:reduce){.hero-scrim::after{animation:none}}

/* image placeholder（画像未設定時のプレースホルダ） */
.ph{position:relative;background:repeating-linear-gradient(45deg,#e9e6da,#e9e6da 12px,#e3dfd1 12px,#e3dfd1 24px);border:1px solid var(--line-2);display:grid;place-items:center;overflow:hidden}
.ph.dark-ph{background:repeating-linear-gradient(45deg,#16241f,#16241f 12px,#122019 12px,#122019 24px);border-color:var(--dark-line)}
.ph .ph-in{font-family:var(--mono);text-align:center;font-size:11px;letter-spacing:.06em;color:var(--muted);line-height:1.9;padding:12px 14px;background:rgba(245,243,236,.86);border-radius:2px}
.ph.dark-ph .ph-in{background:rgba(12,21,18,.7);color:var(--on-dark-mut)}
.ph .ph-in b{display:block;font-size:12px;color:var(--green-d);letter-spacing:.1em}
.ph.dark-ph .ph-in b{color:var(--green-br)}
.ph img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}

/* form */
.signup{display:flex;gap:10px;flex-wrap:wrap;max-width:500px}
.signup input{flex:1 1 220px;min-width:0;font:inherit;font-size:15px;padding:15px 18px;border-radius:3px;border:1px solid var(--line-2);background:#fff;color:var(--ink)}
.signup input:focus{outline:none;border-color:var(--green);box-shadow:0 0 0 3px rgba(0,139,139,.14)}
.form-note{font-size:12px;color:var(--muted);margin-top:12px;letter-spacing:.03em}
.form-ok{display:none;margin-top:16px;background:rgba(0,139,139,.08);color:var(--green-ink);border:1px solid rgba(0,139,139,.28);border-radius:3px;padding:15px 18px;font-size:14px}
.form-ok.show{display:block}
.band.dark .signup input{border-color:transparent}
.band.dark .form-note{color:var(--on-dark-mut)}
.band.dark .form-ok{background:rgba(31,185,169,.12);border-color:rgba(31,185,169,.4);color:var(--on-dark)}

/* philosophy */
.philo{display:grid;grid-template-columns:1fr 1.15fr;gap:clamp(30px,5vw,70px);align-items:center}
@media(max-width:840px){.philo{grid-template-columns:1fr;gap:34px}}
.philo h2{font-size:clamp(2rem,4.6vw,3.2rem);line-height:1.45}
.philo .big-quote{font-family:var(--serif);font-size:clamp(2.2rem,5vw,3.5rem);line-height:1.5;color:var(--on-dark)}
.philo .big-quote em{font-style:normal;color:var(--green-br)}

/* challenges */
.head-row{display:flex;justify-content:space-between;align-items:flex-end;gap:24px;flex-wrap:wrap}
.challenges{display:grid;grid-template-columns:repeat(3,1fr);margin-top:52px;border-top:1px solid var(--line)}
@media(max-width:820px){.challenges{grid-template-columns:1fr}}
.challenge{padding:34px 30px 34px 30px;border-bottom:1px solid var(--line)}
.challenge:not(:last-child){border-right:1px solid var(--line)}
.challenge .idx{font-family:var(--mono);font-size:12px;color:var(--green-d);letter-spacing:.1em}
.challenge h3{font-size:20px;margin:16px 0 10px;line-height:1.5}
.challenge p{margin:0;color:var(--ink-2);font-size:14.5px}
@media(min-width:821px){.challenge:nth-child(3){padding-right:0}}

/* approach */
.approach{display:grid;grid-template-columns:.9fr 1.1fr;gap:clamp(36px,5vw,72px);align-items:start}
@media(max-width:900px){.approach{grid-template-columns:1fr;gap:40px}}
.approach-fig .ph{aspect-ratio:4/5;border-radius:2px}
.approach-list{display:flex;flex-direction:column}
.step{display:grid;grid-template-columns:auto 1fr;gap:24px;padding:30px 0;border-bottom:1px solid var(--line)}
.step:first-child{padding-top:0}
.step:last-child{border-bottom:0}
.step .no{font-family:var(--serif);font-size:40px;line-height:1;color:var(--green-d);min-width:64px}
.step h3{font-size:20px;margin:0 0 9px}
.step p{margin:0;color:var(--ink-2);font-size:14.5px}

/* value */
.value{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;margin-top:52px;background:var(--line);border:1px solid var(--line)}
@media(max-width:720px){.value{grid-template-columns:1fr}}
.val{background:var(--paper);padding:38px 34px}
.val .vi{width:40px;height:40px;color:var(--green-d)}
.val h3{font-size:20px;margin:20px 0 10px}
.val p{margin:0;color:var(--ink-2);font-size:14.5px}

/* stats */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:30px}
@media(max-width:760px){.stats{grid-template-columns:repeat(2,1fr);gap:40px 20px}}
.stat .n{font-family:var(--serif);font-size:clamp(2.6rem,5vw,3.6rem);line-height:1;color:#fff}
.stat .n small{font-size:.42em;color:var(--green-br);margin-left:4px}
.stat .l{font-size:12.5px;color:var(--on-dark-mut);margin-top:14px;letter-spacing:.06em}
.stat{padding-top:22px;border-top:1px solid var(--dark-line)}

/* voices */
.voices{display:grid;grid-template-columns:repeat(3,1fr);gap:26px;margin-top:52px}
@media(max-width:820px){.voices{grid-template-columns:1fr}}
.voice{border-top:2px solid var(--green);padding-top:24px}
.voice p{font-family:var(--serif);font-size:17px;line-height:1.95;color:var(--ink);margin:0 0 20px}
.voice .who{font-size:12.5px;color:var(--muted);letter-spacing:.04em}
.voice .who b{color:var(--ink-2);font-weight:600}

/* faq */
.faq{max-width:820px;margin:44px auto 0;border-top:1px solid var(--line)}
details{border-bottom:1px solid var(--line)}
summary{cursor:pointer;list-style:none;font-weight:600;font-size:16px;padding:22px 40px 22px 0;position:relative}
summary::-webkit-details-marker{display:none}
summary::after{content:"＋";position:absolute;right:4px;top:22px;color:var(--green-d);font-weight:400;transition:transform .2s}
details[open] summary::after{content:"−"}
details .a{padding:0 0 24px;color:var(--ink-2);font-size:14.5px;max-width:680px}

/* final cta */
.cta-inner{text-align:center;max-width:720px;margin:0 auto}
.cta-inner h2{font-size:clamp(2rem,4.6vw,3rem);line-height:1.4;color:#fff}
.cta-inner .lead{color:var(--on-dark-mut)}
.cta-inner .signup{margin:30px auto 0;justify-content:center}
.cta-inner .form-ok{max-width:500px;margin-left:auto;margin-right:auto}

/* footer */
.lp-footer{background:var(--dark-2);color:var(--on-dark-mut);padding:70px 0 34px;border-top:1px solid var(--dark-line)}
.foot-top{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:34px;padding-bottom:44px;border-bottom:1px solid var(--dark-line)}
@media(max-width:760px){.foot-top{grid-template-columns:1fr 1fr}}
.foot-brand .brand{color:var(--on-dark)}
.foot-brand p{font-size:13px;line-height:1.9;margin:18px 0 0;max-width:320px}
.foot-col h4{font-family:var(--mono);font-size:10.5px;letter-spacing:.2em;color:var(--green-br);text-transform:uppercase;margin:0 0 16px}
.foot-col ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:12px}
.foot-col a{font-size:13.5px;color:var(--on-dark-mut)}
.foot-col a:hover{color:var(--on-dark)}
.disc{font-size:11px;line-height:1.85;color:#6f7c74;padding:26px 0 0;max-width:920px}
.copy{font-family:var(--mono);font-size:11px;letter-spacing:.1em;color:#5f6c64;margin-top:22px}

/* full-bleed visual break（セクション間のフルブリード画像／動画） */
.breakband{position:relative;height:clamp(260px,40vw,440px);overflow:hidden;background:#0c1512}
.breakband .ph,.breakband .breakvid{position:absolute;inset:0;border:0;border-radius:0}
.breakband .breakvid{width:100%;height:100%;object-fit:cover}
.break-overlay{position:absolute;inset:0;z-index:1;background:linear-gradient(90deg,rgba(8,16,13,.8) 0%,rgba(8,16,13,.5) 55%,rgba(8,16,13,.74) 100%)}
.break-line{position:absolute;inset:0;z-index:2;display:flex;align-items:center;justify-content:center;margin:0;padding:0 26px;text-align:center;font-family:var(--serif);color:var(--on-dark);font-size:clamp(1.5rem,3.2vw,2.6rem);line-height:1.5;letter-spacing:.04em;text-shadow:0 2px 24px rgba(0,0,0,.55)}
.break-line em{font-style:normal;color:var(--green-br)}
.break-tag{position:absolute;z-index:3;left:20px;bottom:16px;font-family:var(--mono);font-size:10px;letter-spacing:.14em;color:rgba(236,233,221,.5)}

/* final CTA background media（最終CTAの背景画像／動画スロット） */
#start{overflow:hidden}
.cta-bg{position:absolute;inset:0;z-index:0;border:0;border-radius:0;width:100%;height:100%;object-fit:cover}
.cta-scrim{position:absolute;inset:0;z-index:1;background:radial-gradient(120% 120% at 50% 40%,rgba(8,16,13,.62),rgba(8,16,13,.88))}
#start .cta-inner{position:relative;z-index:2}

.reveal{opacity:0;transform:translateY(18px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.reveal{opacity:1;transform:none;transition:none}html{scroll-behavior:auto}}