/* =========================================================
   THEMES — switch with a class on <body>:
     theme-trackmix            : TrackMix app colors (src/App.css)
     theme-twilight (default)  : twilight homepage colors (twilight-cng/web css/style.css)
     theme-dark                : first dark draft
   Preview any theme without editing HTML: index.html?theme=twilight
   ========================================================= */
body{ /* = theme-trackmix */
  --font:"Noto Sans JP","Segoe UI","Hiragino Sans","Yu Gothic UI",sans-serif;
  --page-bg:radial-gradient(circle at 10% 0%,#f2e6d4 0%,transparent 40%),radial-gradient(circle at 90% 10%,#d9e7df 0%,transparent 35%),linear-gradient(180deg,#f7f3ec 0%,#ebe4d8 100%);
  --text:#1c1915; --muted:#5d574e; --muted2:#6a6358;
  --accent:#1f6b4f; --accent-hover:#18553f; --on-accent:#f7fff9;
  --accent-soft:#e5f3ec; --accent-soft2:#cfe6da;
  --grad:linear-gradient(90deg,#1f6b4f,#1f6b4f);          /* app has no gradient: solid */
  --btn-bg:#1f6b4f; --btn-bg-hover:#18553f; --btn-text:#f7fff9; --btn-shadow:0 8px 20px rgba(31,107,79,.25);
  --panel:#fffdf8; --panel-2:rgba(255,253,248,.88); --line:#d5cec0; --line-strong:#2f3b33;
  --header-bg:rgba(247,243,236,.85); --footer-bg:#ebe4d8; --footer-text:#5d574e;
  --shadow:0 12px 30px rgba(28,25,21,.08);
  --check:#1f6b4f; --check-bg:#e5f3ec; --th:#1f6b4f;
  --tag-bg:#e5f3ec; --tag-text:#1f6b4f;
  --badge-bg:#8a2f2f; --badge-text:#fff1f1;
  --overlay:rgba(28,25,21,.45);
  --app-bar:#f0ebe2; --app-dot:#d5cec0; --preview-bg:#141816; --preview-line:#2a322d; --preview-text:#c9d2cb;
  --track-bar:#1f6b4f; --track-bg:repeating-linear-gradient(45deg,#ece6da 0 6px,#ddd5c7 6px 12px);
  --ph-line:#d5cec0; --q:#1f6b4f; --dot-bg:#fffdf8;
}
body.theme-twilight{
  --font:"Noto Sans JP","Zen Kaku Gothic Antique",sans-serif;
  --page-bg:#ffffff;
  --text:#583f2f; --muted:#8a7a6d; --muted2:#8a7a6d;
  --accent:#583f2f; --accent-hover:#313131; --on-accent:#583f2f;
  --accent-soft:#f2f8ff; --accent-soft2:#ddeafc;
  --grad:linear-gradient(to right,#ffb9da 0%,#99d6ff 100%);
  --btn-bg:linear-gradient(to right,#ffb9da 0%,#99d6ff 100%); --btn-bg-hover:linear-gradient(to right,#ffb9da 0%,#82c7ff 100%); --btn-text:#583f2f; --btn-shadow:0 8px 20px rgba(153,214,255,.45);
  --panel:#ffffff; --panel-2:#ffffff; --line:#d6dde3; --line-strong:#583f2f;
  --header-bg:rgba(255,255,255,.88); --footer-bg:linear-gradient(to right,#ffb9da 20%,#99d6ff 100%); --footer-text:#583f2f;
  --shadow:0 12px 30px rgba(88,63,47,.08);
  --check:#583f2f; --check-bg:#fdeafc; --th:#583f2f;
  --tag-bg:#fdeafc; --tag-text:#583f2f;
  --badge-bg:#583f2f; --badge-text:#ffffff;
  --overlay:rgba(88,63,47,.35);
  --app-bar:#f2f8ff; --app-dot:#99d6ff; --preview-bg:#ddeafc; --preview-line:#d6dde3; --preview-text:#583f2f;
  --track-bar:linear-gradient(to right,#ffb9da 0%,#99d6ff 100%); --track-bg:#f2f8ff;
  --ph-line:#99d6ff; --q:#99ccff; --dot-bg:#ffffff;
}
body.theme-dark{
  --font:"Noto Sans JP",system-ui,sans-serif;
  --page-bg:radial-gradient(1200px 600px at 80% -10%,#3b2a7a55,transparent 60%),radial-gradient(900px 500px at -10% 20%,#1e3a8a44,transparent 60%),#0d0b1f;
  --text:#e9e7f7; --muted:#a4a0c8; --muted2:#a4a0c8;
  --accent:#a78bfa; --accent-hover:#c4b5fd; --on-accent:#ffffff;
  --accent-soft:#7c3aed33; --accent-soft2:#7c3aed44;
  --grad:linear-gradient(90deg,#a78bfa,#f0abfc);
  --btn-bg:linear-gradient(135deg,#7c3aed,#c026d3); --btn-bg-hover:linear-gradient(135deg,#8b5cf6,#d946ef); --btn-text:#ffffff; --btn-shadow:0 8px 24px #7c3aed55;
  --panel:#1c1840; --panel-2:#151231; --line:#2e2961; --line-strong:#a78bfa;
  --header-bg:#0d0b1fcc; --footer-bg:#0a0918; --footer-text:#a4a0c8;
  --shadow:0 20px 50px #0008;
  --check:#f0abfc; --check-bg:transparent; --th:#a78bfa;
  --tag-bg:#7c3aed44; --tag-text:#f0abfc;
  --badge-bg:#fcd38d; --badge-text:#1a1300;
  --overlay:#05040fcc;
  --app-bar:#231e4f; --app-dot:#4b4590; --preview-bg:#151231; --preview-line:#2e2961; --preview-text:#a4a0c8;
  --track-bar:linear-gradient(90deg,#7c3aed,#c026d3); --track-bg:transparent;
  --ph-line:#2e2961; --q:#a78bfa; --dot-bg:#0d0b1f;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:var(--font);color:var(--text);line-height:1.8;background:var(--page-bg)}
a{color:var(--accent)}
.container{max-width:1080px;margin:0 auto;padding:0 24px}
.narrow{max-width:760px}
section{padding:88px 0}
.section-title{text-align:center;font-size:clamp(1.5rem,3vw,2rem);margin:0 0 48px;font-weight:900}
.section-title::after{content:"";display:block;width:48px;height:3px;margin:12px auto 0;border-radius:2px;background:var(--grad)}

/* 仮 badge */
.kari{display:inline-block;margin-left:.4em;padding:0 .45em;font-size:.65rem;line-height:1.6;font-weight:700;
  color:var(--badge-text);background:var(--badge-bg);border-radius:4px;vertical-align:middle;letter-spacing:0}

/* header */
.site-header{position:sticky;top:0;z-index:20;display:flex;justify-content:space-between;align-items:center;
  padding:12px 24px;background:var(--header-bg);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.logo{font-weight:900;font-size:1.35rem;color:var(--text);text-decoration:none;letter-spacing:.02em;margin:0}
.logo span{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.nav{display:flex;gap:20px;align-items:center}
.nav a{color:var(--muted);text-decoration:none;font-size:.9rem}
.nav a:hover{color:var(--text)}

/* buttons */
.btn{font:inherit;font-weight:700;border:0;cursor:pointer;color:var(--btn-text);border-radius:999px;
  background:var(--btn-bg);box-shadow:var(--btn-shadow);transition:transform .15s,box-shadow .15s}
.btn:hover{transform:translateY(-2px);background:var(--btn-bg-hover)}
.btn-sm{padding:6px 16px;font-size:.85rem}
.btn-lg{padding:16px 40px;font-size:1.1rem}

/* hero */
.hero{padding:72px 0 56px}
.hero-inner{display:grid;grid-template-columns:1fr 1.1fr;gap:40px 56px;align-items:center}
.eyebrow{color:var(--accent);font-weight:700;font-size:.85rem;letter-spacing:.08em;margin:0 0 8px}
.hero h1{font-size:clamp(2rem,5vw,3.2rem);line-height:1.3;margin:0 0 20px;font-weight:900}
.hero h1 em{font-style:normal;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.lead{color:var(--muted);margin:0}
.hero-track{margin:0;background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}
.hero-track img{display:block;width:100%;height:auto;vertical-align:middle}
.hero-track .ph{aspect-ratio:16/10;border:none;border-radius:0}
.hero-cta{grid-column:1/-1;text-align:center;margin-top:16px}
.punch{font-size:clamp(1.3rem,3vw,1.8rem);font-weight:900;margin:0 0 20px}
.sub{color:var(--muted);font-size:.8rem;margin:12px 0 0}

/* app screenshot */
.screen{padding-top:24px}
.app-shot{margin:0 auto;max-width:860px}
.app-titlebar{display:flex;gap:6px;align-items:center;padding:10px 14px;background:var(--app-bar);border:1px solid var(--line);border-bottom:0;border-radius:12px 12px 0 0}
.app-titlebar i{width:10px;height:10px;border-radius:50%;background:var(--app-dot)}
.app-titlebar span{margin-left:8px;font-size:.8rem;color:var(--muted)}
.app-body{background:var(--panel-2);border:1px solid var(--line);border-radius:0 0 12px 12px;padding:20px}
.app-preview{aspect-ratio:16/9;max-width:420px;margin:0 auto 20px;border:2px dashed var(--preview-line);background:var(--preview-bg);border-radius:10px;
  display:grid;place-items:center;color:var(--preview-text);font-size:.85rem;text-align:center;padding:12px}
.app-tracks{list-style:none;margin:0;padding:0}
.app-tracks li{display:grid;grid-template-columns:90px 1fr;align-items:center;gap:12px;padding:8px 0;border-top:1px solid var(--line);font-size:.85rem}
.app-tracks li{position:relative}
.app-tracks b{height:14px;border-radius:7px;background:var(--track-bar);width:var(--w);box-shadow:inset 0 0 0 0 transparent}
.app-shot figcaption{text-align:center;color:var(--muted);font-size:.8rem;margin-top:12px}

/* cards */
.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:24px;max-width:860px;margin:0 auto}
.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:28px;transition:transform .2s,border-color .2s}
.card{box-shadow:var(--shadow)}
.card:hover{transform:translateY(-4px);border-color:var(--accent)}
.card-icon{width:48px;height:48px;display:grid;place-items:center;border-radius:12px;background:var(--accent-soft);font-size:1.4rem;margin-bottom:12px}
.card h3{margin:0 0 8px;font-size:1.15rem}
.card p{margin:0;color:var(--muted);font-size:.92rem}

/* timeline — desktop: brick / interlocking columns via row spans */
.timeline{
  --tl-gap:56px;
  list-style:none;margin:0 auto;padding:0;position:relative;max-width:900px;
  display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);
  column-gap:var(--tl-gap);row-gap:20px;grid-auto-rows:minmax(0,auto);
}
.timeline::before{content:"";position:absolute;left:50%;top:0;bottom:0;width:2px;background:var(--grad);transform:translateX(-1px);opacity:.8;z-index:0}
.step{position:relative;width:auto;margin:0;padding:0;align-self:start;min-width:0;z-index:1;grid-row:span 2}
.step:nth-child(odd){grid-column:1}
.step:nth-child(even){grid-column:2}
/* Start each even step one track later so it sits in the half-gap opposite the left column */
.step:nth-child(1){grid-row:1/span 2}
.step:nth-child(2){grid-row:2/span 2}
.step:nth-child(3){grid-row:3/span 2}
.step:nth-child(4){grid-row:4/span 2}
.step:nth-child(5){grid-row:5/span 2}
.step::before{
  content:"";position:absolute;top:50%;transform:translateY(-50%);width:14px;height:14px;border-radius:50%;
  background:var(--dot-bg);border:3px solid var(--q);z-index:2;box-sizing:border-box;
}
.step:nth-child(odd)::before{right:calc(var(--tl-gap)/-2 - 7px);left:auto}
.step:nth-child(even)::before{left:calc(var(--tl-gap)/-2 - 7px);right:auto}
.step-body{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.step h3{margin:0 0 6px;font-size:1.05rem;display:flex;align-items:center;flex-wrap:wrap;gap:4px}
.num{display:inline-grid;place-items:center;width:28px;height:28px;border-radius:50%;margin-right:6px;font-size:.85rem;
  color:#583f2f;background:#99d6ff;font-weight:700}
.step p{margin:0 0 12px;color:var(--muted);font-size:.9rem}
.ph{aspect-ratio:4/3;border:2px dashed var(--ph-line);border-radius:10px;display:grid;place-items:center;color:var(--muted);font-size:.8rem;overflow:hidden}
.ph img,.app-shot-img{display:block;width:100%;height:100%;object-fit:cover}
.app-shot-img{border-radius:var(--radius);border:1px solid var(--line);box-shadow:var(--shadow)}

/* faq */
.faq details{background:var(--panel);border:1px solid var(--line);border-radius:12px;margin-bottom:12px;overflow:hidden}
.faq summary{cursor:pointer;padding:16px 48px 16px 20px;font-weight:700;list-style:none;position:relative}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:20px;top:50%;transform:translateY(-50%);font-size:1.3rem;color:var(--q);transition:transform .2s}
.faq details[open] summary::after{transform:translateY(-50%) rotate(45deg)}
.faq details p{margin:0;padding:0 20px 16px;color:var(--muted)}

/* footer */
.site-footer{border-top:1px solid var(--line);padding:40px 0;background:var(--footer-bg);color:var(--footer-text)}
.footer-inner{text-align:center}
.footer-links{list-style:none;padding:0;margin:12px 0;display:flex;gap:24px;justify-content:center;flex-wrap:wrap}
.site-footer a{color:var(--footer-text);font-weight:700}
.license,.copy{color:var(--footer-text);font-size:.8rem;margin:4px 0}

/* download panel */
.dl-overlay{position:fixed;inset:0;z-index:50;background:var(--overlay);backdrop-filter:blur(4px);display:flex;justify-content:flex-end}
.dl-overlay[hidden]{display:none}
.dl-panel{position:relative;width:min(480px,100%);height:100%;overflow-y:auto;background:var(--panel-2);border-left:1px solid var(--line);box-shadow:-20px 0 40px rgba(0,0,0,.12);padding:40px 32px;
  animation:slideIn .3s ease-out}
@keyframes slideIn{from{transform:translateX(100%)}to{transform:none}}
.dl-close{position:absolute;top:16px;right:16px;width:36px;height:36px;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--text);font-size:1.2rem;cursor:pointer}
.dl-panel h2{margin:8px 0 4px;font-size:1.6rem}
.dl-desc{color:var(--muted);margin:0 0 24px;font-size:.9rem}
.dl-options{display:grid;gap:16px}
.dl-option{display:block;padding:20px;border-radius:14px;border:1px solid var(--line);background:var(--panel);color:var(--text);text-decoration:none;transition:border-color .2s,transform .15s}
.dl-option:hover{border-color:var(--accent);transform:translateY(-2px)}
.dl-option.recommended{border-color:var(--accent);box-shadow:0 0 0 1px var(--accent),var(--shadow)}
.dl-option .tag{display:inline-block;font-size:.72rem;font-weight:700;padding:2px 10px;border-radius:999px;background:var(--tag-bg);color:var(--tag-text);margin-bottom:6px}
.dl-option strong{display:block;font-size:1.1rem}
.dl-option small{color:var(--muted)}
.dl-note{margin:24px 0 8px;font-size:.85rem}
.dl-terms{color:var(--muted);font-size:.78rem;margin:0}

/* entrance animation — remove `anim` class on <body> (or this block) to disable */
.anim .fade-up{opacity:0;transform:translateY(24px);transition:opacity .7s ease,transform .7s ease}
.anim .fade-up.in{opacity:1;transform:none}
.anim .d1{transition-delay:.12s}.anim .d2{transition-delay:.24s}
@media (prefers-reduced-motion:reduce){.anim .fade-up{opacity:1;transform:none;transition:none}.dl-panel{animation:none}}

/* responsive */
@media (max-width:820px){
  section{padding:64px 0}
  .hero-inner{grid-template-columns:1fr}
  .nav a{display:none}
  .cards{grid-template-columns:1fr}
  .timeline{display:block;--tl-gap:0}
  .timeline::before{left:14px}
  .step,.step:nth-child(odd),.step:nth-child(even){
    display:block;width:auto;margin:0 0 32px;padding:0 0 0 44px;
    grid-column:auto;grid-row:auto;
  }
  .step:last-child{margin-bottom:0}
  .step::before,.step:nth-child(odd)::before,.step:nth-child(even)::before{
    left:6px;right:auto;top:50%;transform:translateY(-50%);
  }
}
.hero-inner>*{min-width:0}
body{overflow-x:hidden}
.theme-twilight .site-footer .logo span{background:none;color:#ffffff}