:root {
  color-scheme: light;
  --canvas: #fbfbfc;
  --surface: #f2f4f7;
  --surface-raised: #ffffff;
  --line: #d4d8e1;
  --line-subtle: #e6e8ed;
  --text: #11141c;
  --text-secondary: #4a5060;
  --text-muted: #747b8b;
  --scarlet: #a51d35;
  --scarlet-dark: #6f1023;
  --scarlet-soft: #f8edef;
  --blue: #2f6f94;
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--text); background: var(--canvas); }
body::before { content: ""; position: fixed; inset: 0; z-index: -2; pointer-events: none; background: linear-gradient(90deg, transparent 49.9%, rgba(112, 18, 37, .025) 50%, transparent 50.1%); }
a { color: inherit; text-decoration: none; }
button { font: inherit; }

.site-header { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; width: min(1220px, calc(100% - 40px)); height: 72px; margin: 0 auto; background: rgba(251, 251, 252, .84); border-bottom: 1px solid rgba(212, 216, 225, .72); backdrop-filter: blur(22px) saturate(1.2); }
.brand { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 720; letter-spacing: -.025em; }
.brand img { display: block; width: 42px; height: 42px; border-radius: 11px; box-shadow: 0 5px 14px rgba(13, 19, 33, .16); }
nav { display: flex; align-items: center; gap: 27px; color: var(--text-secondary); font-size: 13px; }
nav a { padding: 8px 0; border-bottom: 1px solid transparent; }
nav a:hover { color: var(--scarlet-dark); border-bottom-color: var(--scarlet); }
.language-button { color: var(--text); background: rgba(255, 255, 255, .75); border: 1px solid var(--line); border-radius: 999px; padding: 7px 12px; cursor: pointer; }

main { width: min(1220px, calc(100% - 40px)); margin: 0 auto; }
.hero { position: relative; isolation: isolate; overflow: hidden; min-height: 910px; margin-top: 20px; padding: 88px 72px 0; color: #fff; border-radius: 28px; background: #080a12; box-shadow: 0 36px 100px rgba(12, 17, 29, .25); }
.hero::before { content: ""; position: absolute; inset: 0; z-index: -3; background: url("assets/koakuma-library-background.jpg") 62% 45% / cover no-repeat; transform: scale(1.025); }
.hero::after { content: ""; position: absolute; inset: 0; z-index: -2; background: linear-gradient(90deg, rgba(6, 7, 13, .97) 0%, rgba(7, 9, 16, .88) 38%, rgba(7, 9, 16, .3) 72%), linear-gradient(0deg, rgba(6, 8, 15, .9) 0%, transparent 52%); }
.hero-atmosphere { position: absolute; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.hero-atmosphere i { position: absolute; display: block; border-radius: 50%; filter: blur(2px); animation: drift 14s ease-in-out infinite alternate; }
.hero-atmosphere i:nth-child(1) { width: 260px; height: 260px; right: 8%; top: 6%; background: rgba(212, 49, 79, .13); }
.hero-atmosphere i:nth-child(2) { width: 160px; height: 160px; right: 29%; top: 32%; background: rgba(73, 169, 214, .13); animation-delay: -5s; }
.hero-atmosphere i:nth-child(3) { width: 80px; height: 80px; right: 18%; top: 46%; background: rgba(255, 255, 255, .08); animation-delay: -9s; }
@keyframes drift { from { transform: translate3d(-10px, -6px, 0) scale(.96); opacity: .7; } to { transform: translate3d(16px, 12px, 0) scale(1.08); opacity: 1; } }

.hero-copy { position: relative; z-index: 2; width: min(650px, 64%); }
.eyebrow { margin: 0 0 15px; color: var(--scarlet); font-size: 11px; font-weight: 780; letter-spacing: .17em; text-transform: uppercase; }
.hero .eyebrow { color: #ff8ba0; }
h1 { max-width: 780px; margin: 0; white-space: pre-line; font-family: ui-serif, Georgia, "Times New Roman", serif; font-size: clamp(54px, 6.2vw, 82px); font-weight: 620; line-height: .94; letter-spacing: -.052em; }
html[lang="zh-Hans"] h1 { font-size: clamp(50px, 5.7vw, 74px); line-height: 1.02; }
.hero-description { max-width: 610px; margin: 26px 0; color: rgba(255, 255, 255, .74); font-size: 18px; line-height: 1.65; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 11px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 0 17px; border: 1px solid var(--line); border-radius: 10px; font-size: 13px; font-weight: 650; transition: transform .18s, border-color .18s, box-shadow .18s, background .18s; }
.button:hover { transform: translateY(-2px); border-color: #9ca4b4; box-shadow: 0 9px 24px rgba(19, 22, 32, .12); }
.button.primary { color: #11141d; background: #fff; border-color: #fff; }
.hero .button.secondary { color: #fff; background: rgba(15, 18, 29, .54); border-color: rgba(255, 255, 255, .3); backdrop-filter: blur(14px); }
.button.secondary { background: var(--surface-raised); }
.button:disabled { color: var(--text-muted); background: var(--surface); cursor: default; opacity: 1; }
.button:disabled:hover { transform: none; border-color: var(--line); box-shadow: none; }
.requirements { margin-top: 16px; color: rgba(255, 255, 255, .53); font-size: 12px; }

.hero-product { position: absolute; z-index: 2; left: 52px; right: 52px; bottom: -258px; margin: 0; padding: 8px; border: 1px solid rgba(255, 255, 255, .25); border-radius: 21px; background: rgba(238, 242, 247, .85); box-shadow: 0 35px 90px rgba(0, 0, 0, .42); backdrop-filter: blur(20px); transform: perspective(1200px) rotateX(1.8deg); transform-origin: bottom center; }
.hero-product img { display: block; width: 100%; height: auto; border: 1px solid rgba(61, 70, 89, .22); border-radius: 13px; }

.smart-edit-section { padding: 132px 0 112px; }
.smart-edit-lead { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(280px, .65fr); column-gap: 72px; align-items: end; margin-bottom: 48px; }
.smart-edit-lead .eyebrow { grid-column: 1 / -1; }
h2 { margin: 0; font-family: ui-serif, Georgia, "Times New Roman", serif; font-size: clamp(42px, 5.5vw, 70px); font-weight: 620; line-height: .98; letter-spacing: -.045em; }
.smart-edit-lead > p:last-child { margin: 0 0 5px; color: var(--text-secondary); font-size: 16px; line-height: 1.7; }

.smart-edit-product-shot { width: min(760px, 100%); margin: 0 auto; padding: 10px; border: 1px solid var(--line); border-radius: 22px; background: var(--surface-raised); box-shadow: 0 30px 80px rgba(25, 32, 48, .16); }
.smart-edit-product-shot img { display: block; width: 100%; height: auto; border: 1px solid var(--line-subtle); border-radius: 14px; }
.smart-edit-product-shot figcaption { display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 24px; min-height: 64px; padding: 12px 8px 2px; }
.chapter { color: var(--scarlet); font: 700 11px ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .04em; }
.smart-edit-product-shot figcaption p { margin: 0; color: var(--text-secondary); font-size: 13px; }

.format-statement { display: flex; align-items: center; justify-content: space-between; gap: 40px; padding: 34px 4px 0; }
.format-statement > p { max-width: 660px; margin: 0; font-family: ui-serif, Georgia, "Times New Roman", serif; font-size: clamp(24px, 3vw, 38px); font-weight: 620; line-height: 1.1; letter-spacing: -.035em; }
.format-strip { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 7px; margin: 0; padding: 0; list-style: none; }
.format-strip li { padding: 7px 10px; color: var(--blue); border: 1px solid rgba(47, 111, 148, .21); border-radius: 999px; background: #fff; font: 700 10px ui-monospace, SFMono-Regular, Menlo, monospace; }

.quiet-features { display: grid; grid-template-columns: minmax(300px, .8fr) minmax(0, 1.2fr); gap: 80px; padding: 104px 0; border-top: 1px solid var(--line-subtle); }
.quiet-feature-intro { position: sticky; top: 112px; align-self: start; }
.quiet-feature-intro h2 { max-width: 470px; font-size: clamp(38px, 4.4vw, 58px); }
.quiet-feature-list { border-top: 1px solid var(--line); }
.quiet-feature-list article { display: grid; grid-template-columns: 42px 1fr; gap: 20px; padding: 30px 4px; border-bottom: 1px solid var(--line); }
.quiet-feature-list h3 { margin: 0 0 8px; font-family: ui-serif, Georgia, "Times New Roman", serif; font-size: 24px; font-weight: 620; letter-spacing: -.025em; }
.quiet-feature-list p { max-width: 600px; margin: 0; color: var(--text-secondary); font-size: 14px; line-height: 1.65; }

.update-section { position: relative; display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 42px; overflow: hidden; margin: 22px 0 92px; padding: 56px; border: 1px solid #c9a9ae; border-radius: 20px; background: radial-gradient(circle at 93% 13%, rgba(165, 29, 53, .12), transparent 34%), linear-gradient(135deg, var(--scarlet-soft), #fff 62%); }
.update-section > div { max-width: 720px; }
.update-section h2 { font-size: clamp(38px, 4.5vw, 58px); }
.update-section p:last-child { max-width: 650px; margin: 19px 0 0; color: var(--text-secondary); line-height: 1.65; }

footer { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 20px 40px; width: min(1220px, calc(100% - 40px)); margin: 0 auto; padding: 30px 0 42px; color: var(--text-muted); border-top: 1px solid var(--line-subtle); font-size: 11px; }
.company { display: flex; align-items: center; gap: 10px; color: var(--text-secondary); }
.company img { border-radius: 9px; }
.fan-notice { grid-column: 1 / -1; max-width: 900px; margin: 0; color: #858b99; line-height: 1.55; }

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .65s ease, transform .65s cubic-bezier(.2,.8,.2,1); }
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  .hero { min-height: 820px; padding: 72px 46px 0; }
  .hero-copy { width: 76%; }
  .hero-product { left: 28px; right: 28px; bottom: -180px; }
  .smart-edit-lead { grid-template-columns: 1fr; row-gap: 20px; }
  .format-statement { align-items: flex-start; flex-direction: column; }
  .format-strip { justify-content: flex-start; }
  .quiet-features { grid-template-columns: 1fr; gap: 42px; }
  .quiet-feature-intro { position: static; }
}

@media (max-width: 640px) {
  .site-header, main, footer { width: min(100% - 28px, 1220px); }
  nav { gap: 13px; }
  nav a { display: none; }
  .hero { min-height: 700px; padding: 58px 24px 0; border-radius: 21px; }
  .hero::after { background: linear-gradient(90deg, rgba(5, 7, 13, .96), rgba(7, 9, 16, .7)), linear-gradient(0deg, rgba(6, 8, 15, .8), transparent 45%); }
  .hero-copy { width: 100%; }
  h1 { font-size: 52px; }
  html[lang="zh-Hans"] h1 { font-size: 47px; }
  .hero-description { font-size: 16px; }
  .hero-product { left: 14px; right: 14px; bottom: -70px; padding: 4px; border-radius: 13px; transform: none; }
  .hero-product img { border-radius: 8px; }
  .smart-edit-section { padding: 86px 0 76px; }
  .smart-edit-lead { margin-bottom: 30px; }
  .smart-edit-product-shot { padding: 6px; border-radius: 16px; }
  .smart-edit-product-shot figcaption { grid-template-columns: 1fr; gap: 7px; padding: 14px 10px 8px; }
  .format-statement { padding-top: 26px; }
  .quiet-features { padding: 76px 0; }
  .quiet-feature-list article { grid-template-columns: 34px 1fr; padding: 25px 2px; }
  .update-section { grid-template-columns: 1fr; padding: 38px 25px; }
  footer { grid-template-columns: 1fr; }
  .fan-notice { grid-column: 1; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button, .reveal { transition: none; }
  .hero-atmosphere i { animation: none; }
  .reveal { opacity: 1; transform: none; }
}