/* ============================================================
   Ariya · 同音 — Site styles
   Visual system per plan §B2:
     苔金 #B89048 + 霁青 #4FA09B + 双弧共振 + ZH Sans × EN Roman Serif
   ============================================================ */

/* -------- Tokens : Light (default) -------- */
:root {
  --primary:        #B89048;
  --primary-deep:   #8E6B30;
  --primary-soft:   #E8D9B0;
  --secondary:      #4FA09B;
  --secondary-deep: #327B77;
  --secondary-soft: #C5E0DD;
  --accent-glow:    #F5E5A5;

  --ink:        #1E1B16;
  --ink-soft:   #5B544A;
  --ink-quiet:  #8E867A;

  --paper:      #F8F4ED;
  --paper-alt:  #EFE9DD;
  --paper-pure: #FFFFFF;

  --line:        rgba(30, 27, 22, 0.10);
  --line-strong: rgba(30, 27, 22, 0.20);

  --max-w:        1140px;
  --max-w-narrow: 680px;
  --pad-x:        clamp(20px, 5vw, 56px);
  --section-y:    clamp(80px, 12vw, 144px);

  --radius-sm:   6px;
  --radius-md:   12px;
  --radius-lg:   24px;
  --radius-pill: 9999px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --t-fast:  150ms;
  --t-base:  200ms;
  --t-slow:  500ms;

  --font-zh-display: "Source Han Sans SC", "Noto Sans CJK SC", "PingFang SC", sans-serif;
  --font-zh-body:    "PingFang SC", "Hiragino Sans GB", system-ui, sans-serif;
  --font-en-display: "Fraunces", "Source Serif 4", "Times New Roman", serif;
  --font-en-body:    "Inter", -apple-system, "SF Pro Text", "Segoe UI", sans-serif;
}

/* -------- Tokens : Dark -------- */
:root[data-theme="dark"] {
  --primary:        #D4A85B;
  --primary-deep:   #B5904A;
  --primary-soft:   #4A3B1F;
  --secondary:      #6FBDB7;
  --secondary-deep: #4FA09B;
  --secondary-soft: #1F3B39;
  --accent-glow:    #4A3F1F;

  --ink:        #EBE6DC;
  --ink-soft:   #B0A99B;
  --ink-quiet:  #7A736A;

  --paper:      #14110D;
  --paper-alt:  #1E1A14;
  --paper-pure: #0B0907;

  --line:        rgba(235, 230, 220, 0.12);
  --line-strong: rgba(235, 230, 220, 0.22);
}

/* -------- Reset -------- */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}
body {
  font-family: var(--font-zh-body);
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  transition: background var(--t-base) var(--ease), color var(--t-base) var(--ease);
}
html[lang^="en"] body { font-family: var(--font-en-body); }

img, svg { display: block; max-width: 100%; }
a { color: var(--secondary); text-decoration: none; transition: color var(--t-fast) var(--ease); }
a:hover { color: var(--secondary-deep); }

button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

:focus-visible {
  outline: 2px solid var(--secondary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* -------- Layout helpers -------- */
.container { max-width: var(--max-w); margin: 0 auto; padding-inline: var(--pad-x); }
.container--narrow { max-width: var(--max-w-narrow); margin: 0 auto; padding-inline: var(--pad-x); }
.section { padding-block: var(--section-y); }

/* i18n visibility */
[data-i18n-zh], [data-i18n-en] { display: none; }
html[lang^="zh"] [data-i18n-zh] { display: revert; }
html[lang^="en"] [data-i18n-en] { display: revert; }
html[lang^="zh"] [data-i18n-zh-inline] { display: inline; }
html[lang^="en"] [data-i18n-en-inline] { display: inline; }

/* -------- Reveal-on-scroll : 共振 -------- */
.reveal {
  opacity: 0;
  transform: translateY(8px) scale(0.96);
  transition: opacity var(--t-slow) var(--ease), transform var(--t-slow) var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}
.reveal.in-view { opacity: 1; transform: none; }

/* =====================================================
   Nav
   ===================================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 64px;
  display: flex;
  align-items: center;
  background: transparent;
  transition: background var(--t-base) var(--ease), backdrop-filter var(--t-base) var(--ease), border-color var(--t-base) var(--ease);
  border-bottom: 1px solid transparent;
}
.nav--scrolled {
  background: color-mix(in oklab, var(--paper-pure) 80%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--line);
}
.nav__inner {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding-inline: var(--pad-x);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.nav__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-family: var(--font-zh-display);
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.02em;
}
html[lang^="en"] .nav__brand { font-family: var(--font-en-display); font-style: normal; }
.nav__brand .logo { width: 32px; height: 32px; }
.nav__brand-text {
  background: linear-gradient(90deg, var(--ink) 60%, var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
@media (max-width: 720px) {
  .nav__brand-text { display: none; }
}

.nav__actions { display: inline-flex; gap: 8px; align-items: center; }
.icon-btn {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--ink-soft);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}
.icon-btn:hover { border-color: var(--secondary); color: var(--secondary); }
.icon-btn[aria-pressed="true"] { color: var(--primary); border-color: var(--primary); }

/* =====================================================
   Hero
   ===================================================== */
.hero {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 48px;
  align-items: center;
  min-height: calc(100vh - 64px);
  padding-block: clamp(40px, 6vw, 96px);
}
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 24px; min-height: auto; padding-block: 48px; }
}
.hero__kicker {
  font-family: var(--font-en-display);
  font-style: italic;
  font-size: 16px;
  color: var(--primary);
  letter-spacing: 0.02em;
  margin-bottom: 16px;
}
.hero__title {
  margin: 0 0 8px;
  display: flex;
  flex-direction: column;
  gap: 0;
}
.hero__title-zh {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: clamp(64px, 8vw, 96px);
  line-height: 1.0;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.hero__title-en {
  font-family: var(--font-en-display);
  font-weight: 600;
  font-size: clamp(64px, 8vw, 96px);
  line-height: 1.0;
  letter-spacing: -0.01em;
  color: var(--primary);
  font-style: normal;
}
.hero__title-rule {
  align-self: flex-start;
  width: clamp(120px, 18vw, 200px);
  height: 1px;
  background: var(--line-strong);
  margin: 8px 0;
}
.hero__subtitle-zh {
  font-family: var(--font-zh-display);
  font-weight: 500;
  font-size: clamp(22px, 2.6vw, 32px);
  line-height: 1.4;
  color: var(--ink-soft);
  margin: 24px 0 8px;
}
.hero__subtitle-en {
  font-family: var(--font-en-display);
  font-weight: 400;
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.5;
  color: var(--secondary);
  margin: 8px 0 24px;
}
.hero__sub2 {
  font-size: 14px;
  color: var(--ink-quiet);
  letter-spacing: 0.02em;
  margin-bottom: 24px;
}
.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--paper-alt);
  color: var(--ink-soft);
  border-radius: var(--radius-pill);
  font-size: 12px;
  letter-spacing: 0.04em;
  border: 1px solid var(--line);
  margin-bottom: 24px;
}
.status-pill::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--primary) 30%, transparent);
}

.hero__cta { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 48px;
  padding: 0 24px;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform var(--t-base) var(--ease), background var(--t-base) var(--ease), color var(--t-base) var(--ease), border-color var(--t-base) var(--ease);
  white-space: nowrap;
}
.btn--primary {
  background: var(--primary);
  color: var(--paper);
  border: 1px solid var(--primary);
}
.btn--primary:hover { background: var(--primary-deep); border-color: var(--primary-deep); transform: translateY(-2px); }
.btn--ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line-strong);
}
.btn--ghost:hover { border-color: var(--ink); transform: translateY(-2px); }
.btn .arrow { transition: transform var(--t-fast) var(--ease); }
.btn:hover .arrow { transform: translateX(4px); }

/* Hero art (right column) */
.hero__art {
  width: 100%;
  max-width: 400px;
  aspect-ratio: 1 / 1;
  margin-inline: auto;
  position: relative;
  display: grid;
  place-items: center;
}
.hero__art-svg { width: 100%; height: 100%; }

/* Logo entrance animation (only first time, on hero motif) */
.hero__art-svg .arc-a, .hero__art-svg .arc-b {
  stroke-dasharray: 600;
  stroke-dashoffset: 600;
  animation: ariya-arc-draw 500ms var(--ease) 200ms forwards;
}
.hero__art-svg .arc-b {
  animation-delay: 200ms;
}
@keyframes ariya-arc-draw {
  to { stroke-dashoffset: 0; }
}
.hero__art-svg .resonance {
  opacity: 0;
  animation: ariya-resonance-in 600ms var(--ease) 700ms forwards;
}
@keyframes ariya-resonance-in {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}

/* =====================================================
   Divider — 双弧分割线
   ===================================================== */
.divider {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-inline: var(--pad-x);
  max-width: var(--max-w);
  margin: 0 auto;
  padding-block: 8px;
}
.divider__line {
  flex: 1;
  height: 1px;
  background: var(--line-strong);
  transform: scaleX(0);
  transform-origin: var(--origin, right);
  transition: transform 700ms var(--ease);
}
.divider__line--right { --origin: left; }
.divider.in-view .divider__line { transform: scaleX(1); }
.divider__mark {
  width: 32px;
  height: 32px;
  flex: 0 0 32px;
}

/* =====================================================
   Three pillars — Features
   ===================================================== */
.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
@media (max-width: 900px) {
  .pillars { grid-template-columns: 1fr; }
}
.pillar {
  position: relative;
  padding: 32px;
  background: var(--paper-pure);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  transition: border-color var(--t-base) var(--ease), transform var(--t-base) var(--ease), box-shadow var(--t-base) var(--ease);
  overflow: hidden;
}
.pillar:hover {
  border-color: var(--secondary);
  transform: translateY(-4px);
  box-shadow: 0 24px 60px -32px color-mix(in oklab, var(--secondary) 40%, transparent);
}
.pillar__numeral {
  font-family: var(--font-en-display);
  font-weight: 600;
  font-size: 100px;
  line-height: 1;
  color: var(--ink-quiet);
  opacity: 0.45;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}
.pillar__title-zh {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: 32px;
  line-height: 1.2;
  color: var(--ink);
  margin: 0;
}
.pillar__title-en {
  font-family: var(--font-en-display);
  font-weight: 600;
  font-style: normal;
  font-size: 24px;
  line-height: 1.3;
  color: var(--primary);
  margin: 4px 0 16px;
}
.pillar__sub {
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.6;
  margin: 0 0 20px;
}
.pillar__meta {
  font-family: var(--font-en-body);
  font-size: 12px;
  color: var(--secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.pillar__decor {
  position: absolute;
  right: 16px;
  bottom: 16px;
  width: 28px;
  height: 28px;
  opacity: 0.18;
  pointer-events: none;
}

.section-kicker {
  font-family: var(--font-en-display);
  font-style: italic;
  font-weight: 400;
  font-size: 14px;
  color: var(--secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin: 0 0 12px;
}
.section-title {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.2;
  color: var(--ink);
  margin: 0 0 12px;
}
html[lang^="en"] .section-title { font-family: var(--font-en-display); font-weight: 600; }
.section-lede {
  color: var(--ink-soft);
  font-size: 18px;
  line-height: 1.6;
  max-width: 60ch;
  margin: 0 0 48px;
}

/* =====================================================
   Pull quote
   ===================================================== */
.pull {
  text-align: center;
  padding-block: var(--section-y);
}
.pull__en {
  font-family: var(--font-en-display);
  font-style: italic;
  font-weight: 600;
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.3;
  color: var(--primary);
  margin: 0;
  letter-spacing: -0.005em;
}
.pull__rule {
  width: 80px;
  height: 1px;
  background: var(--line-strong);
  margin: 24px auto;
}
.pull__zh {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: clamp(22px, 3vw, 36px);
  line-height: 1.4;
  color: var(--ink);
  margin: 0;
  letter-spacing: 0.06em;
}

/* =====================================================
   Showcase — 双声波示意
   ===================================================== */
.showcase__title-zh {
  font-family: var(--font-zh-display);
  font-weight: 700;
  font-size: clamp(22px, 3vw, 28px);
  line-height: 1.4;
  color: var(--ink);
  margin: 0 0 4px;
  text-align: center;
}
.showcase__title-en {
  font-family: var(--font-en-display);
  font-style: italic;
  font-weight: 500;
  font-size: clamp(16px, 2vw, 22px);
  line-height: 1.5;
  color: var(--ink-soft);
  margin: 0 0 32px;
  text-align: center;
}
.showcase__frame {
  aspect-ratio: 16 / 9;
  background: var(--paper-pure);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}
.showcase__svg { width: 100%; height: 100%; display: block; }

/* Showcase orbital wave system — 6 ellipses 绕 motif 流动,
   不同速度 + 部分反向,营造"包裹 + 洪流"感(dash-offset 沿椭圆周长流动) */
@keyframes orbit-flow {
  to { stroke-dashoffset: -200; }
}
.orbit-1 { animation: orbit-flow 14s linear infinite; }
.orbit-2 { animation: orbit-flow 10s linear infinite reverse; }
.orbit-3 { animation: orbit-flow 8s  linear infinite; }
.orbit-4 { animation: orbit-flow 11s linear infinite reverse; }
.orbit-5 { animation: orbit-flow 6s  linear infinite; }
.orbit-6 { animation: orbit-flow 5s  linear infinite reverse; }

.showcase__caption {
  text-align: center;
  font-size: 12px;
  color: var(--ink-quiet);
  margin: 16px 0 0;
}

/* =====================================================
   Secondary CTA
   ===================================================== */
.cta-band {
  background: var(--paper-alt);
  position: relative;
  overflow: hidden;
  padding-block: var(--section-y);
}
.cta-band__watermark {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 80%;
  max-width: 720px;
  opacity: 0.06;
  pointer-events: none;
}
.cta-band__inner { position: relative; text-align: center; }
.cta-band__title-zh {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: clamp(28px, 5vw, 56px);
  line-height: 1.25;
  color: var(--ink);
  margin: 0 0 12px;
  letter-spacing: 0.02em;
}
.cta-band__title-en {
  font-family: var(--font-en-display);
  font-weight: 600;
  font-style: normal;
  font-size: clamp(22px, 4vw, 40px);
  line-height: 1.3;
  color: var(--primary);
  margin: 0 0 32px;
}

/* =====================================================
   FAQ
   ===================================================== */
.faq { display: flex; flex-direction: column; gap: 8px; }
.faq__item {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--paper-pure);
  padding: 0 24px;
  transition: border-color var(--t-base) var(--ease);
}
.faq__item:hover { border-color: var(--line-strong); }
.faq__item[open] { border-color: var(--secondary); }
.faq__item summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__q-zh {
  font-family: var(--font-zh-display);
  font-weight: 600;
  font-size: 17px;
  color: var(--ink);
}
.faq__q-en {
  font-family: var(--font-en-display);
  font-weight: 500;
  font-style: normal;
  font-size: 16px;
  color: var(--ink-soft);
  margin-left: 12px;
}
.faq__plus {
  flex: 0 0 24px;
  width: 24px;
  height: 24px;
  display: inline-grid;
  place-items: center;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  font-size: 16px;
  line-height: 1;
  color: var(--ink-soft);
  transition: transform var(--t-base) var(--ease), border-color var(--t-base) var(--ease), color var(--t-base) var(--ease);
}
.faq__item[open] .faq__plus { transform: rotate(45deg); border-color: var(--secondary); color: var(--secondary); }
.faq__a {
  padding: 0 0 18px;
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.7;
}

/* =====================================================
   Footer
   ===================================================== */
.footer {
  border-top: 1px solid var(--line);
  background: var(--paper);
  padding-block: 64px 32px;
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: 40px;
}
@media (max-width: 900px) {
  .footer__grid { grid-template-columns: 1fr; gap: 32px; }
}
.footer__brand { display: flex; flex-direction: column; gap: 12px; }
.footer__brand-row { display: flex; align-items: center; gap: 12px; }
.footer__brand-name {
  font-family: var(--font-zh-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--ink);
}
.footer__tagline {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
  max-width: 36ch;
}
.footer__col h4 {
  font-family: var(--font-en-display);
  font-style: italic;
  font-weight: 500;
  font-size: 12px;
  color: var(--ink-quiet);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 12px;
}
.footer__col ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer__col a {
  color: var(--ink-soft);
  font-size: 14px;
  transition: color var(--t-fast) var(--ease);
}
.footer__col a:hover { color: var(--ink); }
.footer__col .disabled {
  color: var(--ink-quiet);
  font-size: 14px;
  cursor: not-allowed;
}
.footer__col .disabled small { color: var(--secondary); margin-left: 6px; font-style: italic; }
.footer__company {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.7;
}
.footer__bottom {
  border-top: 1px solid var(--line);
  margin-top: 48px;
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 12px;
  color: var(--ink-quiet);
}
.footer__bottom-mark { width: 20px; height: 20px; opacity: 0.6; }

/* =====================================================
   Legal pages
   ===================================================== */
.legal { padding-block: var(--section-y); }
.legal h1 {
  font-family: var(--font-zh-display);
  font-weight: 800;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.2;
  margin: 0 0 8px;
  color: var(--ink);
}
.legal h1 + .legal__en {
  font-family: var(--font-en-display);
  font-weight: 500;
  font-style: italic;
  font-size: 22px;
  color: var(--ink-soft);
  margin: 0 0 32px;
}
.legal h2 {
  font-family: var(--font-zh-display);
  font-weight: 700;
  font-size: 22px;
  margin: 48px 0 12px;
  color: var(--ink);
}
.legal p { color: var(--ink-soft); font-size: 16px; line-height: 1.8; margin: 0 0 16px; }
.legal__updated {
  font-size: 13px;
  color: var(--ink-quiet);
  margin: 0 0 32px;
}

/* =====================================================
   Reduced motion
   ===================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0ms !important;
    animation-delay: 0ms !important;
    transition-duration: 0ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .divider__line { transform: scaleX(1); }
  .hero__art-svg .arc-a,
  .hero__art-svg .arc-b { stroke-dashoffset: 0; }
  .hero__art-svg .resonance { opacity: 1; transform: none; }
}