/* ============================================================
   ShelfStream — landing page
   「本棚・紙・藍」— 自炊漫画/書籍リーダーのアイデンティティ。
   生成り紙 (washi) × 墨 (sumi) × 藍 (ai) + 背表紙の彩り。
   ============================================================ */

/* --- design tokens ------------------------------------------------------- */
:root {
  /* washi paper / sumi ink palette */
  --paper-50:  #FCFAF5;
  --paper-100: #F7F3EA;
  --paper-200: #EFE9DB;
  --paper-300: #E3DAC7;
  --paper-400: #D2C6AC;

  --ink-900: #12141A;
  --ink-800: #1B1E26;
  --ink-700: #2B2F3A;
  --ink-600: #414654;
  --ink-500: #5D6371;
  --ink-400: #7F8595;
  --ink-300: #A9AEBC;

  /* ai (藍) — ShelfStream のアクセント。装丁の藍色 */
  --ai-600:      #2C5DB8;   /* primary accent */
  --ai-500:      #3D74D6;
  --ai-700:      #1E4488;   /* deep */
  --ai-100:      #DCE7F8;

  /* 背表紙の彩り — spine triad */
  --spine-red:    #C9503A;   /* 朱 */
  --spine-amber:  #DBA33C;   /* 山吹 */
  --spine-green:  #4E7D5B;   /* 松葉 */

  --bg:        var(--paper-100);
  --bg-soft:   var(--paper-50);
  --surface:   #FFFFFF;
  --surface-2: var(--paper-200);
  --fg:        var(--ink-800);
  --fg-soft:   var(--ink-500);
  --fg-muted:  var(--ink-400);
  --border:        rgba(27, 30, 38, 0.10);
  --border-strong: rgba(27, 30, 38, 0.20);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 22px;
  --radius-xl: 36px;
  --radius-pill: 999px;

  --shadow-sm: 0 1px 2px rgba(18,20,26,0.05), 0 1px 3px rgba(18,20,26,0.04);
  --shadow-md: 0 8px 22px rgba(18,20,26,0.08), 0 2px 6px rgba(18,20,26,0.04);
  --shadow-lg: 0 32px 56px rgba(18,20,26,0.14), 0 12px 22px rgba(18,20,26,0.07);
  --shadow-glow: 0 24px 60px -12px rgba(44,93,184,0.30);

  --container: 1180px;
  --gutter: clamp(20px, 4vw, 48px);

  /* fonts */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-display: "Zen Kaku Gothic New", "Noto Sans JP", "Noto Sans KR", "Noto Sans SC", "ヒラギノ角ゴシック ProN", "Hiragino Sans", system-ui, sans-serif;
  --font-mincho:  "Shippori Mincho", "Noto Serif JP", "Noto Serif KR", "Noto Serif SC", "ヒラギノ明朝 ProN", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --font-num: "Inter", system-ui, sans-serif;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-1: 220ms;
  --dur-2: 380ms;
  --dur-3: 700ms;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #0C0E13;
    --bg-soft:   #0F1218;
    --surface:   #171B24;
    --surface-2: #1F2430;
    --fg:        var(--paper-100);
    --fg-soft:   #C3C8D4;
    --fg-muted:  #848B9C;
    --border:        rgba(247, 243, 234, 0.10);
    --border-strong: rgba(247, 243, 234, 0.22);
    --ai-600:      #5B8DE8;
    --ai-500:      #78A3F0;
    --ai-700:      #3D6FD0;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
    --shadow-md: 0 6px 18px rgba(0,0,0,0.5);
    --shadow-lg: 0 24px 48px rgba(0,0,0,0.6);
    --shadow-glow: 0 24px 60px -12px rgba(91,141,232,0.34);
  }
}

/* --- reset / base -------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.7;
  font-feature-settings: "ss01", "cv11", "kern", "palt";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  text-wrap: pretty;
  /* very subtle paper grain */
  background-image:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='280' height='280'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.09  0 0 0 0 0.09  0 0 0 0 0.11  0 0 0 0.035 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

/* CJK 自動改行（kinsoku） */
p, li, .lead, summary { line-break: strict; word-break: normal; overflow-wrap: break-word; }
h1, h2, h3, .display, .manifesto-quote { line-break: strict; word-break: keep-all; text-wrap: balance; }
@supports (word-break: auto-phrase) {
  p, li, .lead { word-break: auto-phrase; }
}
.nowrap { white-space: nowrap; }

img, svg, video { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; transition: color var(--dur-1) var(--ease), opacity var(--dur-1) var(--ease); }
a:hover { color: var(--ai-700); }
@media (prefers-color-scheme: dark) { a:hover { color: var(--ai-500); } }
button { font: inherit; color: inherit; cursor: pointer; }

::selection { background: var(--ai-600); color: #fff; }

:focus-visible { outline: 2px solid var(--ai-600); outline-offset: 3px; border-radius: 4px; }

/* --- layout primitives --------------------------------------------------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding-inline: var(--gutter); position: relative; }

/* --- typography ---------------------------------------------------------- */
h1, h2, h3, h4 { color: var(--fg); margin: 0 0 0.5em; line-height: 1.2; letter-spacing: 0.005em; font-weight: 700; font-family: var(--font-display); }
h1 { font-size: clamp(38px, 5.2vw, 70px); line-height: 1.16; }
h2 { font-size: clamp(30px, 4.2vw, 54px); }
h3 { font-size: clamp(20px, 2.4vw, 28px); }
p  { margin: 0 0 1em; color: var(--fg-soft); max-width: 60ch; }
.lead { font-size: clamp(18px, 1.6vw, 21px); color: var(--fg-soft); line-height: 1.65; max-width: 38em; }
.subtle { color: var(--fg-muted); }
.accent { color: var(--ai-600); font-style: normal; }
.accent-warm { color: var(--spine-amber); font-style: normal; }

.eyebrow {
  font-family: var(--font-sans);
  font-size: 11px; font-weight: 700;
  letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--fg-muted);
  margin: 0 0 18px;
  display: inline-flex; align-items: center; gap: 10px;
}
.eyebrow::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--ai-600); flex: 0 0 auto; box-shadow: 0 0 0 4px color-mix(in srgb, var(--ai-600) 18%, transparent); }
.eyebrow.center { justify-content: center; display: flex; }

.eyebrow-vert {
  writing-mode: vertical-rl;
  font-family: var(--font-mincho);
  font-size: 13px; letter-spacing: 0.4em;
  color: var(--fg-muted);
  position: absolute; left: 0; top: 0;
}

/* --- top nav ------------------------------------------------------------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  backdrop-filter: saturate(160%) blur(18px);
  -webkit-backdrop-filter: saturate(160%) blur(18px);
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-2) var(--ease), background var(--dur-2) var(--ease);
}
.nav.is-stuck { border-bottom-color: var(--border); background: color-mix(in srgb, var(--bg) 92%, transparent); }
.nav-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 68px; }

.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 700; }
.brand-mark { width: 32px; height: 32px; border-radius: 9px; box-shadow: var(--shadow-sm); flex: 0 0 auto; }
.brand-name { font-family: var(--font-display); font-size: 21px; font-weight: 700; letter-spacing: -0.01em; }

.nav-links { display: none; gap: 30px; align-items: center; }
.nav-links a { color: var(--fg-soft); font-size: 14px; font-weight: 600; }
.nav-links a:hover { color: var(--fg); }
.nav-cta { display: inline-flex; align-items: center; gap: 14px; }
@media (min-width: 920px) { .nav-links { display: inline-flex; } }
.nav-cta .btn-primary { display: none; }
@media (min-width: 560px) { .nav-cta .btn-primary { display: inline-flex; } }

/* language switcher */
.lang-wrap { position: relative; }
.lang-switch {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 14px; border: 1px solid var(--border-strong); border-radius: var(--radius-pill);
  background: transparent; font-size: 13px; font-weight: 600; color: var(--fg-soft);
  transition: border-color var(--dur-1) var(--ease), color var(--dur-1) var(--ease);
}
.lang-switch:hover { border-color: var(--fg); color: var(--fg); }
.lang-switch svg { width: 16px; height: 16px; }
.lang-menu {
  position: absolute; right: 0; top: calc(100% + 8px);
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  box-shadow: var(--shadow-md); padding: 6px; display: none; min-width: 172px; z-index: 60;
}
.lang-wrap.is-open .lang-menu { display: block; }
.lang-menu a { display: flex; justify-content: space-between; align-items: baseline; gap: 14px; padding: 9px 12px; border-radius: 9px; font-size: 14px; color: var(--fg-soft); }
.lang-menu a:hover { background: var(--surface-2); color: var(--fg); }
.lang-menu a[aria-current="true"] { color: var(--ai-600); font-weight: 700; }
.lang-menu small { color: var(--fg-muted); font-size: 11px; letter-spacing: 0.06em; }

/* --- buttons ------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  padding: 14px 26px; font-size: 15px; font-weight: 700;
  border: 1px solid transparent; border-radius: var(--radius-pill);
  cursor: pointer; user-select: none; white-space: nowrap; line-height: 1;
  transition: background var(--dur-1) var(--ease), color var(--dur-1) var(--ease),
              border-color var(--dur-1) var(--ease), transform var(--dur-2) var(--ease),
              box-shadow var(--dur-2) var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--ai-600); color: #fff; }
.btn-primary:hover { background: var(--ai-700); color: #fff; box-shadow: var(--shadow-glow); transform: translateY(-1px); }
@media (prefers-color-scheme: dark) {
  .btn-primary { background: var(--ai-600); color: #0A1220; }
  .btn-primary:hover { background: var(--ai-500); color: #0A1220; }
}
.btn-ghost { background: transparent; color: var(--fg); border-color: var(--border-strong); }
.btn-ghost:hover { background: var(--surface); color: var(--fg); border-color: var(--fg); }
@media (prefers-color-scheme: dark) { .btn-ghost:hover { background: var(--surface-2); } }

/* App Store badge */
.appstore-badge {
  display: inline-flex; align-items: center; gap: 13px;
  padding: 11px 22px;
  background: var(--ink-900); color: var(--paper-50);
  border-radius: 14px; border: 1px solid var(--ink-700);
  position: relative; overflow: hidden;
  transition: transform var(--dur-2) var(--ease), background var(--dur-1) var(--ease), box-shadow var(--dur-2) var(--ease);
}
.appstore-badge:hover { background: var(--ink-800); color: var(--paper-50); transform: translateY(-1px); box-shadow: var(--shadow-glow); }
.appstore-badge svg { width: 28px; height: 28px; flex: 0 0 auto; }
.appstore-badge .as-small { display: block; font-size: 10px; line-height: 1.1; opacity: 0.72; letter-spacing: 0.06em; text-transform: uppercase; }
.appstore-badge .as-big { display: block; font-size: 18px; font-weight: 700; line-height: 1.15; letter-spacing: -0.01em; }
@media (prefers-color-scheme: dark) {
  .appstore-badge { background: var(--paper-100); color: var(--ink-800); border-color: var(--paper-200); }
  .appstore-badge:hover { background: var(--paper-50); color: var(--ink-800); }
}

/* QR code chip (desktop only) */
.qr-chip {
  display: none; align-items: center; gap: 12px;
  padding: 10px 16px 10px 10px;
  border: 1px dashed var(--border-strong); border-radius: 16px;
  color: var(--fg-muted); font-size: 12px; line-height: 1.4;
}
.qr-chip img { width: 62px; height: 62px; border-radius: 8px; background: #fff; padding: 4px; }
@media (min-width: 980px) { .qr-chip { display: inline-flex; } }

/* --- HERO ---------------------------------------------------------------- */
.hero {
  position: relative; min-height: 100vh;
  padding-block: clamp(120px, 12vw, 180px) clamp(60px, 8vw, 100px);
  overflow: hidden; isolation: isolate;
}

/* watermark 棚 (= 本棚。ShelfStream の独自価値) */
.hero-watermark {
  position: absolute; top: 46%; left: 58%;
  transform: translate(-50%, -50%);
  font-family: var(--font-mincho);
  font-size: clamp(420px, 76vw, 1120px);
  line-height: 0.82; font-weight: 600;
  color: var(--ai-700);
  opacity: 0.055; user-select: none; pointer-events: none;
  z-index: 0; letter-spacing: -0.06em;
}
@media (prefers-color-scheme: dark) { .hero-watermark { color: var(--ai-500); opacity: 0.07; } }

/* 本棚の背表紙モチーフ（ヒーロー下端・ShelfStream の署名モチーフ） */
.hero-shelf {
  position: absolute; left: 0; right: 0; bottom: 0; height: clamp(90px, 14vw, 170px);
  z-index: 0; pointer-events: none;
  display: flex; align-items: flex-end; gap: 6px;
  padding-inline: 4vw;
  mask-image: linear-gradient(90deg, transparent 0%, #000 12%, #000 88%, transparent 100%);
  -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 12%, #000 88%, transparent 100%);
  opacity: 0.16;
}
@media (prefers-color-scheme: dark) { .hero-shelf { opacity: 0.22; } }
.hero-shelf span {
  flex: 1 1 auto; border-radius: 4px 4px 0 0;
  background: var(--ink-400);
  transform-origin: bottom center;
  animation: spine-rise 900ms var(--ease-out) both;
}
.hero-shelf span:nth-child(6n+1) { background: var(--ai-600);     height: 78%; animation-delay: 60ms; }
.hero-shelf span:nth-child(6n+2) { background: var(--ink-500);    height: 92%; animation-delay: 140ms; }
.hero-shelf span:nth-child(6n+3) { background: var(--spine-red);  height: 70%; animation-delay: 220ms; }
.hero-shelf span:nth-child(6n+4) { background: var(--ai-700);     height: 86%; animation-delay: 300ms; }
.hero-shelf span:nth-child(6n+5) { background: var(--spine-amber);height: 64%; animation-delay: 380ms; }
.hero-shelf span:nth-child(6n+6) { background: var(--spine-green);height: 82%; animation-delay: 460ms; }
@keyframes spine-rise { from { transform: scaleY(0); } to { transform: scaleY(1); } }
@media (prefers-reduced-motion: reduce) { .hero-shelf span { animation: none; } }

.hero-grid {
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1fr;
  gap: clamp(40px, 6vw, 80px); align-items: center;
}
@media (min-width: 980px) { .hero-grid { grid-template-columns: 8fr 4.6fr; align-items: center; } }

.hero-text { position: relative; padding-left: clamp(0px, 4vw, 40px); }
.hero-text .eyebrow-vert { display: none; }
@media (min-width: 980px) {
  .hero-text { padding-left: 56px; }
  .hero-text .eyebrow-vert { display: block; }
}

.hero h1 { margin-bottom: 26px; font-weight: 800; line-height: 1.16; }
.hero .lead { margin-bottom: 34px; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
.hero-meta {
  margin-top: 34px; display: flex; flex-wrap: wrap; gap: 0;
  color: var(--fg-muted); font-size: 12px; letter-spacing: 0.08em;
  text-transform: uppercase; font-weight: 600;
}
.hero-meta > span { padding: 0 14px; border-right: 1px solid var(--border); }
.hero-meta > span:first-child { padding-left: 0; }
.hero-meta > span:last-child { border-right: none; }

/* reading-progress demo ticker */
.hero-ticker {
  margin-top: 26px; display: inline-flex; align-items: center; gap: 12px;
  padding: 9px 18px;
  background: color-mix(in srgb, var(--surface) 80%, transparent);
  border: 1px solid var(--border); border-radius: var(--radius-pill);
  font-size: 13px; color: var(--fg-soft);
}
.hero-ticker .demo-tag {
  font-size: 10px; font-weight: 800; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--fg-muted); padding-right: 11px; margin-right: 1px; border-right: 1px solid var(--border);
}
.hero-ticker .page-now { font-family: var(--font-num); font-weight: 800; font-size: 17px; font-feature-settings: "tnum"; color: var(--ai-600); }
.hero-ticker .page-total { font-size: 12px; color: var(--fg-muted); }
.hero-ticker .page-bar { width: 74px; height: 5px; border-radius: 999px; background: color-mix(in srgb, var(--ink-400) 22%, transparent); overflow: hidden; }
.hero-ticker .page-fill { display: block; height: 100%; width: 0%; border-radius: 999px; background: var(--ai-600); transition: width 900ms var(--ease); }

/* phone visual */
.hero-visual { position: relative; display: flex; justify-content: center; align-items: center; }
.phone {
  position: relative; width: min(100%, 350px); aspect-ratio: 350 / 720;
  background: var(--ink-900); border-radius: 52px; padding: 11px;
  box-shadow: inset 0 0 0 1.5px rgba(255,255,255,0.08), 0 40px 80px -20px rgba(18,20,26,0.42), 0 16px 32px -8px rgba(18,20,26,0.20);
  isolation: isolate; transform: rotate(-2.5deg);
  transition: transform 800ms var(--ease-out);
}
.hero:hover .phone { transform: rotate(-1.2deg) translateY(-4px); }
@media (prefers-reduced-motion: reduce) { .phone, .hero:hover .phone { transform: none; } }
.phone::before { content: ""; position: absolute; top: 17px; left: 50%; transform: translateX(-50%); width: 108px; height: 30px; background: #000; border-radius: 999px; z-index: 3; }
.phone-screen { position: relative; width: 100%; height: 100%; border-radius: 42px; overflow: hidden; background: var(--paper-100); }
.phone-screen img { width: 100%; height: 100%; object-fit: cover; object-position: top; }

/* --- stat band (by the numbers) ------------------------------------------ */
.statband { padding-block: clamp(54px, 7vw, 84px); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: var(--bg-soft); }
.statband-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 4vw, 56px) clamp(20px, 3vw, 40px); }
@media (min-width: 760px) { .statband-grid { grid-template-columns: repeat(4, 1fr); } }
.stat { text-align: center; position: relative; }
.stat-num { font-family: var(--font-num); font-weight: 800; font-size: clamp(44px, 6vw, 72px); line-height: 1; letter-spacing: -0.03em; color: var(--ai-600); font-feature-settings: "tnum"; }
.stat-num .u { font-size: 0.42em; font-weight: 700; color: var(--fg-muted); margin-left: 2px; letter-spacing: 0; }
.stat:nth-child(2) .stat-num { color: var(--fg); }
.stat:nth-child(3) .stat-num { color: var(--fg); }
.stat:nth-child(4) .stat-num { color: var(--ai-600); }
.stat-label { margin-top: 10px; font-size: 13px; color: var(--fg-muted); letter-spacing: 0.04em; }
.stat-label b { display: block; color: var(--fg-soft); font-size: 14px; font-weight: 700; letter-spacing: 0.01em; margin-bottom: 1px; }

/* --- manifesto ----------------------------------------------------------- */
.manifesto { position: relative; padding-block: clamp(100px, 14vw, 190px); overflow: hidden; background: var(--bg); }
.manifesto::before {
  content: ""; position: absolute; inset: 0;
  background-image: radial-gradient(circle, var(--ai-600) 1.5px, transparent 1.7px);
  background-size: 38px 38px; background-position: 19px 19px; opacity: 0.07; pointer-events: none;
  mask-image: radial-gradient(ellipse 90% 80% at 50% 50%, #000 40%, transparent 90%);
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 50% 50%, #000 40%, transparent 90%);
}
.manifesto-quote {
  position: relative; font-family: var(--font-display); font-weight: 800;
  font-size: clamp(34px, 5.4vw, 76px); line-height: 1.45;
  color: var(--fg); max-width: 20ch; margin: 0 auto; text-align: center; letter-spacing: 0.01em;
}
.manifesto-quote .accent { color: var(--ai-600); }
.manifesto-quote .small { display: block; font-size: 0.4em; color: var(--fg-muted); margin-top: 0.9em; letter-spacing: 0.18em; text-transform: uppercase; font-family: var(--font-sans); font-weight: 700; }

/* --- moments ------------------------------------------------------------- */
.moment { position: relative; padding-block: clamp(92px, 12vw, 172px); overflow: hidden; }
.moment-grid { display: grid; grid-template-columns: 1fr; gap: clamp(40px, 6vw, 80px); align-items: center; }
@media (min-width: 880px) {
  .moment-grid { grid-template-columns: 6fr 5fr; gap: clamp(48px, 6vw, 96px); }
  .moment-grid.flip { grid-template-columns: 5fr 6fr; }
  .moment-grid.flip > .moment-text { order: 2; }
}
.moment-num {
  font-family: var(--font-num); font-size: 13px; letter-spacing: 0.36em; font-feature-settings: "tnum";
  color: var(--fg-muted); margin-bottom: 22px; display: inline-flex; align-items: center; gap: 12px;
}
.moment-num::after { content: ""; flex: 0 0 56px; height: 1px; background: var(--border-strong); }
.moment h2 { font-weight: 800; font-size: clamp(32px, 4.4vw, 60px); line-height: 1.22; margin-bottom: 24px; letter-spacing: 0.005em; }
.moment p { font-size: 17px; max-width: 40ch; }
.moment-bullets { padding: 0; margin: 30px 0 0; list-style: none; }
.moment-bullets li { padding-left: 28px; position: relative; color: var(--fg-soft); margin-bottom: 12px; font-size: 16px; }
.moment-bullets li::before { content: ""; position: absolute; left: 0; top: 0.62em; width: 9px; height: 9px; border-radius: 50%; background: var(--ai-600); }
.moment-bullets li.premium::after { content: "Premium"; margin-left: 9px; font-size: 10px; font-weight: 800; letter-spacing: 0.08em; color: var(--ai-700); background: color-mix(in srgb, var(--ai-600) 16%, transparent); padding: 2px 8px; border-radius: 999px; vertical-align: middle; }

.moment-visual { position: relative; display: flex; justify-content: center; align-items: center; }
.moment-visual .frame {
  position: relative; background: linear-gradient(155deg, var(--paper-200), var(--paper-100));
  padding: clamp(26px, 4.6vw, 52px); border-radius: var(--radius-xl);
  border: 1px solid var(--border); box-shadow: var(--shadow-lg);
  display: grid; place-items: center; width: 100%; max-width: 540px;
}
@media (prefers-color-scheme: dark) { .moment-visual .frame { background: linear-gradient(155deg, var(--surface-2), var(--surface)); } }
.moment-visual .frame img { max-width: 272px; border-radius: 26px; box-shadow: var(--shadow-md); }
.moment-visual .frame.tilt-l { transform: rotate(-1.5deg); }
.moment-visual .frame.tilt-r { transform: rotate(1.5deg); }

/* iPhone + iPad の duo（moment-3 ライブラリ） */
.device-duo { position: relative; width: 100%; max-width: 340px; display: flex; justify-content: flex-end; padding: 6px 0 26px; }
.device-duo .duo-tablet {
  width: 82%; max-width: 262px; aspect-ratio: 3 / 4;
  background: linear-gradient(150deg, #2a2d36, #14161c);
  border-radius: 24px; padding: 9px;
  transform: rotate(1.6deg);
  box-shadow: 0 26px 52px -14px rgba(0,0,0,0.5), inset 0 0 0 1px rgba(255,255,255,0.1);
}
.device-duo .duo-tablet .tablet-screen { width: 100%; height: 100%; border-radius: 16px; overflow: hidden; background: #000; }
.device-duo .duo-tablet img { width: 100%; height: 100%; object-fit: cover; object-position: top; }
.device-duo .duo-phone {
  position: absolute; left: -4%; bottom: 0;
  width: 44%; max-width: 148px; aspect-ratio: 1284 / 2778;
  background: var(--ink-900); border-radius: 26px; padding: 5px;
  transform: rotate(-4deg);
  box-shadow: 0 22px 44px -12px rgba(0,0,0,0.55), inset 0 0 0 1px rgba(255,255,255,0.12);
}
.device-duo .duo-phone .duo-phone-screen { width: 100%; height: 100%; border-radius: 21px; overflow: hidden; background: #000; }
.device-duo .duo-phone img { width: 100%; height: 100%; object-fit: cover; object-position: top; }

/* moment backgrounds */
.moment.bg-cream { background: var(--paper-100); }
@media (prefers-color-scheme: dark) { .moment.bg-cream { background: var(--bg-soft); } }
.moment.bg-ai {
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg) 18%, var(--ai-700) 18%, #16336B 100%);
  color: var(--paper-50);
}
.moment.bg-ai h2, .moment.bg-ai .moment-num, .moment.bg-ai p, .moment.bg-ai .moment-bullets li, .moment.bg-ai .eyebrow { color: var(--paper-100); }
.moment.bg-ai .accent { color: #BAD3F7; }
.moment.bg-ai .eyebrow::before { background: #BAD3F7; box-shadow: 0 0 0 4px rgba(186,211,247,0.2); }
.moment.bg-ai .moment-bullets li::before { background: #BAD3F7; }
.moment.bg-ai .moment-num::after { background: rgba(247,243,234,0.32); }
.moment.bg-ai .moment-visual .frame { background: linear-gradient(155deg, rgba(247,243,234,0.12), rgba(247,243,234,0.04)); border-color: rgba(247,243,234,0.18); }
.moment.bg-ai .moment-bullets li.premium::after { color: #16336B; background: #BAD3F7; }

.moment.bg-sumi { background: var(--ink-900); color: var(--paper-100); }
.moment.bg-sumi h2 { color: var(--paper-100); }
.moment.bg-sumi p, .moment.bg-sumi .moment-bullets li, .moment.bg-sumi .moment-num { color: rgba(247,243,234,0.78); }
.moment.bg-sumi .eyebrow { color: rgba(247,243,234,0.6); }
.moment.bg-sumi .accent { color: var(--ai-500); }
.moment.bg-sumi .eyebrow::before { background: var(--ai-500); box-shadow: 0 0 0 4px rgba(91,141,232,0.18); }
.moment.bg-sumi .moment-bullets li::before { background: var(--ai-500); }
.moment.bg-sumi .moment-num::after { background: rgba(247,243,234,0.3); }
.moment.bg-sumi .moment-visual .frame { background: linear-gradient(155deg, #1E222C, #13161D); border-color: rgba(247,243,234,0.10); }
.moment.bg-sumi .moment-bullets li.premium::after { color: #0A1220; background: var(--ai-500); }

/* --- moment-1 signature visual: ダウンロード vs ストリーミング ------------- */
.span-compare { width: 100%; max-width: 460px; display: flex; flex-direction: column; gap: 22px; }
.span-row .span-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 9px; }
.span-row .span-name { font-weight: 700; font-size: 15px; color: var(--fg); }
.span-row .span-val { font-family: var(--font-num); font-feature-settings: "tnum"; font-size: 13px; color: var(--fg-muted); }
.span-track { height: 16px; border-radius: 999px; background: color-mix(in srgb, var(--ink-400) 18%, transparent); overflow: hidden; position: relative; }
.span-fill { height: 100%; border-radius: 999px; transform-origin: left center; }
.span-fill.download { width: 100%; background: repeating-linear-gradient(135deg, var(--spine-red) 0 8px, color-mix(in srgb, var(--spine-red) 70%, #000) 8px 16px); }
.span-fill.stream {
  width: 7%;
  background: linear-gradient(90deg, var(--ai-600) 0%, var(--ai-500) 100%);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--ai-600) 40%, transparent) inset;
}
.span-note { margin-top: 4px; font-size: 12.5px; color: var(--fg-muted); }
.span-note .accent { color: var(--ai-600); font-weight: 700; }
.span-caption { text-align: center; font-family: var(--font-num); font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--fg-muted); margin-top: 2px; }

/* connection chips (クラウド/NAS 対応サービス) */
.conn-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; padding: 0; list-style: none; }
.conn-chips li {
  font-family: var(--font-num); font-size: 12.5px; font-weight: 600; letter-spacing: 0.02em;
  color: var(--fg-soft); background: color-mix(in srgb, var(--surface) 85%, transparent);
  border: 1px solid var(--border); border-radius: 999px; padding: 5px 13px;
}
.conn-chips li.hl { color: var(--ai-700); border-color: color-mix(in srgb, var(--ai-600) 40%, transparent); background: color-mix(in srgb, var(--ai-600) 9%, transparent); }
@media (prefers-color-scheme: dark) { .conn-chips li.hl { color: var(--ai-500); } }

/* --- formats table (SEO リッチな対応一覧) --------------------------------- */
.formats { padding-block: clamp(84px, 11vw, 150px); background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.formats-head { text-align: center; max-width: 720px; margin: 0 auto 52px; }
.formats-table-wrap { max-width: 880px; margin: 0 auto; overflow-x: auto; border: 1px solid var(--border-strong); border-radius: var(--radius-lg); background: var(--surface); box-shadow: var(--shadow-sm); }
.formats-table { width: 100%; border-collapse: collapse; font-size: 15px; }
.formats-table th, .formats-table td { text-align: left; padding: 16px 22px; border-bottom: 1px solid var(--border); vertical-align: top; }
.formats-table tr:last-child th, .formats-table tr:last-child td { border-bottom: none; }
.formats-table th { width: 34%; font-family: var(--font-display); font-weight: 700; color: var(--fg); white-space: nowrap; }
.formats-table td { color: var(--fg-soft); }
.formats-table td .tag { display: inline-block; font-family: var(--font-num); font-size: 12.5px; font-weight: 600; background: color-mix(in srgb, var(--ai-600) 9%, transparent); color: var(--ai-700); border-radius: 6px; padding: 2px 9px; margin: 2px 4px 2px 0; }
@media (prefers-color-scheme: dark) { .formats-table td .tag { color: var(--ai-500); } }

/* --- adfree strip (広告なし・プライバシー) --------------------------------- */
.adfree { position: relative; padding-block: clamp(96px, 13vw, 180px); background: var(--ink-900); color: var(--paper-100); text-align: center; overflow: hidden; }
.adfree::before {
  content: "読"; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  font-family: var(--font-mincho); font-size: clamp(340px, 56vw, 720px); color: var(--ai-500); opacity: 0.05;
  line-height: 0.9; pointer-events: none; user-select: none; z-index: 0;
}
.adfree .container { position: relative; z-index: 1; max-width: 760px; }
.adfree .eyebrow { color: rgba(247,243,234,0.6); justify-content: center; display: flex; }
.adfree .eyebrow::before { background: var(--ai-500); box-shadow: 0 0 0 4px rgba(91,141,232,0.2); }
.adfree h2 { font-size: clamp(34px, 5vw, 68px); color: var(--paper-50); line-height: 1.2; margin-bottom: 20px; }
.adfree h2 .accent { color: var(--ai-500); }
.adfree p { color: rgba(247,243,234,0.78); margin: 0 auto 18px; max-width: 40em; font-size: clamp(16px, 1.6vw, 18px); }
.adfree-points { list-style: none; padding: 0; margin: 36px auto 0; max-width: 620px; display: grid; gap: 14px; grid-template-columns: 1fr; text-align: left; }
@media (min-width: 640px) { .adfree-points { grid-template-columns: 1fr 1fr; } }
.adfree-points li { display: flex; gap: 12px; align-items: flex-start; color: rgba(247,243,234,0.86); font-size: 15px; }
.adfree-points li svg { width: 20px; height: 20px; flex: 0 0 auto; margin-top: 2px; color: var(--ai-500); }

/* --- spine segmented divider --------------------------------------------- */
.shelf-divider { max-width: 320px; margin: 0 auto; padding-block: clamp(40px, 6vw, 64px); display: flex; align-items: flex-end; gap: 5px; }
.shelf-divider span { border-radius: 3px 3px 0 0; }
.shelf-divider .s-1 { flex: 0 0 12%; height: 18px; background: var(--ai-600); }
.shelf-divider .s-2 { flex: 0 0 20%; height: 24px; background: var(--ink-500); }
.shelf-divider .s-3 { flex: 0 0 10%; height: 14px; background: var(--spine-red); }
.shelf-divider .s-4 { flex: 1 1 auto; height: 22px; background: var(--ai-700); }
.shelf-divider .s-5 { flex: 0 0 14%; height: 16px; background: var(--spine-amber); }
.shelf-divider .s-6 { flex: 0 0 16%; height: 20px; background: var(--spine-green); }

/* --- pricing ------------------------------------------------------------- */
.pricing-section { padding-block: clamp(96px, 13vw, 180px); }
.pricing-head { text-align: center; max-width: 640px; margin: 0 auto 60px; }
.pricing-head h2 { font-size: clamp(32px, 4.4vw, 58px); margin-bottom: 14px; }
.pricing-head .lead { margin-inline: auto; }
.pricing { display: grid; grid-template-columns: 1fr; max-width: 980px; margin: 0 auto; border: 1px solid var(--border-strong); border-radius: var(--radius-xl); overflow: hidden; background: var(--bg); }
@media (min-width: 720px) { .pricing { grid-template-columns: 1fr 1fr; } }
.plan { padding: clamp(36px, 5vw, 56px) clamp(28px, 4vw, 46px); display: flex; flex-direction: column; gap: 16px; position: relative; }
.plan + .plan { border-top: 1px solid var(--border-strong); }
@media (min-width: 720px) { .plan + .plan { border-top: none; border-left: 1px solid var(--border-strong); } }
.plan.is-premium { background: var(--ink-900); color: var(--paper-50); }
.plan.is-premium h3, .plan.is-premium .plan-tag, .plan.is-premium .plan-num, .plan.is-premium li, .plan.is-premium .plan-yearly { color: var(--paper-100); }
.plan.is-premium li { color: rgba(247,243,234,0.86); }
.plan.is-premium li::before { background: var(--ai-500); }
.plan.is-premium .plan-yearly { color: rgba(247,243,234,0.62); }
.plan-tag { font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--fg-muted); font-weight: 800; }
.plan.is-premium .plan-tag { color: var(--ai-500); }
.plan h3 { font-size: 23px; font-weight: 700; margin: 0; }
.plan-num { font-family: var(--font-num); font-size: clamp(52px, 7vw, 80px); font-weight: 800; line-height: 0.95; letter-spacing: -0.03em; color: var(--fg); margin: 8px 0 4px; font-feature-settings: "tnum"; display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.plan-num .yen { font-size: 0.6em; font-weight: 700; }
.plan-num small { font-size: 14px; color: var(--fg-muted); font-weight: 600; letter-spacing: 0.01em; flex: 1 1 auto; line-height: 1.4; }
.plan.is-premium .plan-num small { color: rgba(247,243,234,0.62); }
.plan-yearly { font-size: 13px; color: var(--fg-muted); }
.plan ul { list-style: none; padding: 0; margin: 6px 0 14px; display: flex; flex-direction: column; gap: 10px; }
.plan li { color: var(--fg-soft); font-size: 15px; padding-left: 24px; position: relative; }
.plan li::before { content: ""; position: absolute; left: 0; top: 0.58em; width: 8px; height: 8px; border-radius: 50%; background: var(--ai-600); }
.plan .btn { align-self: flex-start; margin-top: 6px; }
.plan.is-premium .btn-primary { background: var(--ai-500); color: #0A1220; }
.plan.is-premium .btn-primary:hover { background: #8FB3F2; color: #0A1220; }
.plan-foot { font-size: 12.5px; color: var(--fg-muted); margin: 4px 0 0; }
.plan.is-premium .plan-foot { color: rgba(247,243,234,0.55); }

/* --- FAQ ----------------------------------------------------------------- */
.faq-section { padding-block: clamp(96px, 13vw, 180px); position: relative; }
.faq-head { text-align: center; max-width: 640px; margin: 0 auto 60px; }
.faq-head h2 { font-size: clamp(32px, 4.4vw, 58px); }
.faq { max-width: 800px; margin: 0 auto; }
.faq details { border-bottom: 1px solid var(--border); padding: 26px 0; }
.faq details:first-child { border-top: 1px solid var(--border); }
.faq summary {
  list-style: none; cursor: pointer; font-family: var(--font-display); font-weight: 700;
  font-size: clamp(17px, 2vw, 21px); display: flex; justify-content: space-between; align-items: center; gap: 16px; color: var(--fg);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; width: 22px; height: 22px; border-radius: 50%; border: 1.5px solid var(--ai-600); flex: 0 0 auto;
  background-image: linear-gradient(var(--ai-600), var(--ai-600)), linear-gradient(var(--ai-600), var(--ai-600));
  background-size: 10px 1.6px, 1.6px 10px; background-position: center, center; background-repeat: no-repeat;
  transition: transform var(--dur-2) var(--ease);
}
.faq details[open] summary::after { background-size: 10px 1.6px, 0 0; transform: rotate(180deg); }
.faq details p { margin-top: 16px; font-size: 16px; max-width: 64ch; line-height: 1.75; }

/* --- final CTA ----------------------------------------------------------- */
.cta-section { padding-block: clamp(96px, 14vw, 200px); background: linear-gradient(165deg, var(--ai-700), #1A3A75 70%, #142C5C); color: var(--paper-100); text-align: center; position: relative; overflow: hidden; }
.cta-section::before {
  content: "棚"; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  font-family: var(--font-mincho); font-size: clamp(360px, 60vw, 800px); color: #fff; opacity: 0.06;
  pointer-events: none; user-select: none; line-height: 0.9; z-index: 0;
}
.cta-section .container { position: relative; z-index: 1; }
.cta-section .eyebrow { color: rgba(255,255,255,0.65); justify-content: center; display: flex; }
.cta-section .eyebrow::before { background: #BAD3F7; box-shadow: 0 0 0 4px rgba(186,211,247,0.22); }
.cta-section h2 { font-size: clamp(38px, 6vw, 86px); color: #fff; line-height: 1.2; margin-bottom: 18px; letter-spacing: 0.01em; }
.cta-section p { color: rgba(255,255,255,0.82); margin: 0 auto 34px; max-width: 38em; font-size: clamp(16px, 1.6vw, 19px); }
.cta-section .appstore-badge { background: #fff; color: var(--ink-900); border-color: rgba(255,255,255,0.4); }
.cta-section .appstore-badge:hover { background: var(--paper-50); }

/* --- footer -------------------------------------------------------------- */
.footer { padding-block: 64px 48px; border-top: 1px solid var(--border); }
.footer-grid { display: grid; gap: 40px; grid-template-columns: 1fr; }
@media (min-width: 720px) { .footer-grid { grid-template-columns: 1.6fr 1fr 1fr 1fr; } }
.footer h4 { font-family: var(--font-sans); font-size: 11px; text-transform: uppercase; letter-spacing: 0.18em; color: var(--fg-muted); margin-bottom: 16px; font-weight: 800; }
.footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.footer a { font-size: 14px; color: var(--fg-soft); }
.footer a:hover { color: var(--fg); }
.footer .brand { margin-bottom: 16px; }
.footer .copy { color: var(--fg-muted); font-size: 12px; margin-top: 36px; letter-spacing: 0.02em; }
.footer .disclaimer { color: var(--fg-muted); font-size: 12px; max-width: 62ch; line-height: 1.7; margin-top: 8px; }

/* --- section progress dots (right edge) ---------------------------------- */
.section-dots { position: fixed; right: 24px; top: 50%; transform: translateY(-50%); z-index: 30; display: none; flex-direction: column; gap: 14px; padding: 14px 8px; }
@media (min-width: 1040px) { .section-dots { display: flex; } }
.section-dots a { width: 9px; height: 9px; border-radius: 50%; background: var(--border-strong); transition: background var(--dur-2) var(--ease), transform var(--dur-2) var(--ease); position: relative; }
.section-dots a:hover { background: var(--fg); transform: scale(1.3); }
.section-dots a.is-active { background: var(--ai-600); transform: scale(1.55); }
.section-dots a span { position: absolute; right: 24px; top: 50%; transform: translateY(-50%); white-space: nowrap; font-size: 11px; letter-spacing: 0.1em; color: var(--fg); background: var(--surface); border: 1px solid var(--border); padding: 4px 10px; border-radius: 999px; opacity: 0; pointer-events: none; transition: opacity var(--dur-1) var(--ease); }
.section-dots a:hover span, .section-dots a.is-active span { opacity: 1; }

/* --- reveal -------------------------------------------------------------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity var(--dur-3) var(--ease-out), transform var(--dur-3) var(--ease-out); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal-stagger > * { opacity: 0; transform: translateY(14px); transition: opacity var(--dur-3) var(--ease-out), transform var(--dur-3) var(--ease-out); }
.reveal-stagger.is-visible > * { opacity: 1; transform: none; }
.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 90ms; }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 180ms; }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 270ms; }
@media (prefers-reduced-motion: reduce) { .reveal, .reveal-stagger > * { opacity: 1; transform: none; } }

/* --- skip link ----------------------------------------------------------- */
.skip { position: absolute; left: -9999px; top: 8px; padding: 10px 16px; background: var(--ai-600); color: #fff; border-radius: 8px; z-index: 100; font-size: 14px; }
.skip:focus { left: 16px; }