/* ============================================================
   Trustone Law LLP · 美国晟合律师事务所
   Design system — "cornerstone of trust, union of two worlds"
   Palette: ink navy + brass + limestone paper
   ============================================================ */

:root {
  /* Brand */
  --navy:        #0E2340;   /* deep ink navy — authority, the "stone" */
  --navy-800:    #14304F;
  --navy-700:    #1B3A6B;   /* from the source document */
  --brass:       #B4924F;   /* restrained gold accent */
  --brass-600:   #9C7C3D;
  --brass-soft:  #C9A84C;   /* from the source document */

  /* Neutrals — limestone, not cream */
  --paper:       #F4F2EC;   /* page background — limestone */
  --paper-2:     #ECE8DF;   /* alt band */
  --card:        #FBFAF6;
  --ink:         #17202B;   /* body text */
  --ink-soft:    #4A5560;   /* secondary text */
  --line:        #DED9CC;   /* hairline */
  --line-strong: #C8C0AD;

  /* Type */
  --font-display: 'Fraunces', 'Noto Serif SC', Georgia, 'Songti SC', serif;
  --font-body:    'Hanken Grotesk', 'Noto Sans SC', system-ui, -apple-system, 'PingFang SC', sans-serif;

  /* Layout */
  --wrap:  1160px;
  --gutter: clamp(1.25rem, 4vw, 3rem);
  --radius: 3px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { margin: 0; font-weight: 500; line-height: 1.12; letter-spacing: -0.01em; }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }

/* ---------- Language switching ---------- */
html[data-lang="zh"] .lang-en { display: none !important; }
html[data-lang="en"] .lang-zh { display: none !important; }
/* Chinese text tuned slightly for CJK rhythm */
html[data-lang="zh"] body { letter-spacing: 0.01em; }

.skip-link {
  position: fixed; top: -60px; left: 12px; z-index: 200;
  background: var(--navy); color: #fff; padding: 10px 16px; border-radius: var(--radius);
  transition: top .2s var(--ease);
}
.skip-link:focus { top: 12px; }

/* ---------- Layout helpers ---------- */
.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }
.section { padding-block: clamp(4.5rem, 9vw, 8rem); }

.section-eyebrow, .eyebrow {
  font-size: 0.75rem; font-weight: 600; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--brass-600); margin: 0;
}
html[data-lang="zh"] .section-eyebrow,
html[data-lang="zh"] .eyebrow { letter-spacing: 0.28em; }

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.2vw, 3rem);
  color: var(--navy);
  margin-top: 0.7rem;
  font-weight: 500;
}
.section-head { max-width: 40ch; margin-bottom: clamp(2.5rem, 5vw, 4rem); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 0.5em;
  font-family: var(--font-body); font-weight: 600; font-size: 0.95rem;
  padding: 0.85em 1.5em; border-radius: 999px; cursor: pointer;
  border: 1px solid transparent; transition: all .25s var(--ease);
  letter-spacing: 0.01em;
}
.btn-arrow { width: 1.05em; height: 1.05em; transition: transform .25s var(--ease); }
.btn:hover .btn-arrow { transform: translateX(3px); }
.btn-primary { background: var(--navy); color: #F5F1E7; }
.btn-primary:hover { background: var(--navy-800); box-shadow: 0 10px 26px -12px rgba(14,35,64,.6); }
.btn-ghost { background: transparent; color: var(--navy); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--navy); background: rgba(14,35,64,.04); }

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s var(--ease), background .3s var(--ease);
}
.site-header.scrolled {
  border-bottom-color: var(--line);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
}
.header-inner { display: flex; align-items: center; gap: 1.5rem; min-height: 72px; }

.brand { display: inline-flex; align-items: center; gap: 0.7rem; margin-right: auto; }
.brand-mark { display: inline-flex; }
.brand-mark-img { display: block; border-radius: 50%; }
.brand-text { display: flex; flex-direction: column; line-height: 1.05; }
.brand-en {
  font-family: var(--font-display); font-weight: 600; font-size: 1.18rem;
  color: var(--navy); letter-spacing: 0.005em;
}
.brand-zh {
  font-family: var(--font-body); font-size: 0.72rem; letter-spacing: 0.18em;
  color: var(--ink-soft); margin-top: 1px;
}

.site-nav { display: flex; align-items: center; gap: clamp(1rem, 2.4vw, 2.1rem); }
.site-nav a {
  font-size: 0.95rem; font-weight: 500; color: var(--ink-soft);
  position: relative; padding: 4px 0; transition: color .2s var(--ease);
}
.site-nav a::after {
  content: ""; position: absolute; left: 0; bottom: -2px; height: 1.5px; width: 0;
  background: var(--brass); transition: width .25s var(--ease);
}
.site-nav a:hover, .site-nav a.active { color: var(--navy); }
.site-nav a:hover::after, .site-nav a.active::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: 0.6rem; }
.lang-toggle {
  font-family: var(--font-body); font-weight: 600; font-size: 0.82rem;
  letter-spacing: 0.06em;
  border: 1px solid var(--line-strong); background: transparent; color: var(--navy);
  padding: 0.42em 0.85em; border-radius: 999px; cursor: pointer;
  transition: all .2s var(--ease); min-width: 3.4em; text-align: center;
}
.lang-toggle:hover { border-color: var(--navy); background: var(--navy); color: var(--paper); }

.nav-burger { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-burger span {
  display: block; width: 22px; height: 2px; background: var(--navy); border-radius: 2px;
  transition: transform .3s var(--ease), opacity .2s var(--ease);
}
.nav-burger span + span { margin-top: 5px; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative; overflow: hidden;
  padding-block: clamp(4rem, 11vw, 8.5rem) clamp(3.5rem, 8vw, 6rem);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(27,58,107,.06), transparent 60%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-2) 100%);
  border-bottom: 1px solid var(--line);
}
.hero-glyph {
  position: absolute; right: -0.12em; bottom: -0.28em; z-index: 0;
  font-family: var(--font-display); font-weight: 600;
  font-size: clamp(20rem, 42vw, 40rem); line-height: 0.8;
  color: var(--navy); opacity: 0.045; pointer-events: none; user-select: none;
}
.hero-inner { position: relative; z-index: 1; max-width: 60rem; }

.eyebrow { display: flex; align-items: center; gap: 0.7rem; flex-wrap: wrap; }
.eyebrow-dot { width: 4px; height: 4px; border-radius: 50%; background: var(--brass); }

.hero-title { margin-top: 1.4rem; }
.hero-name-en {
  display: block; font-family: var(--font-display); font-weight: 500;
  font-size: clamp(3rem, 9vw, 6.4rem); color: var(--navy);
  letter-spacing: -0.02em; line-height: 0.98;
}
.hero-name-zh {
  display: block; font-family: var(--font-display); font-weight: 600;
  font-size: clamp(1.35rem, 4vw, 2.3rem); color: var(--navy-700);
  letter-spacing: 0.08em; margin-top: 0.55rem;
}
.hero-lead {
  max-width: 40ch; margin-top: 1.8rem;
  font-size: clamp(1.08rem, 1.6vw, 1.3rem); color: var(--ink-soft); line-height: 1.6;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.9rem; margin-top: 2.3rem; }

.cred-strip {
  display: flex; flex-wrap: wrap; gap: 0.6rem 1.6rem;
  margin-top: clamp(2.5rem, 5vw, 3.6rem);
  padding-top: 1.6rem; border-top: 1px solid var(--line);
}
.cred-strip li {
  position: relative; padding-left: 1.1rem;
  font-size: 0.9rem; color: var(--ink-soft); font-weight: 500;
}
.cred-strip li::before {
  content: ""; position: absolute; left: 0; top: 0.62em;
  width: 5px; height: 5px; background: var(--brass); transform: rotate(45deg);
}

/* ============================================================
   ABOUT
   ============================================================ */
.section-about { background: var(--paper); }
.about-grid { display: grid; grid-template-columns: 0.85fr 1.15fr; gap: clamp(2rem, 5vw, 5rem); align-items: start; }
.about-head { position: sticky; top: 96px; }
.about-body p { font-size: 1.12rem; color: var(--ink); max-width: 60ch; }
.about-body p + p { margin-top: 1.4rem; }
.about-body p .lang-en { line-height: 1.72; }

/* ============================================================
   PRACTICE
   ============================================================ */
.section-practice { background: var(--navy); color: #E8E4D8; }
.section-practice .section-eyebrow { color: var(--brass-soft); }
.section-practice .section-title { color: #F5F1E7; }

.practice-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px;
  background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.1);
}
.practice-card {
  background: var(--navy); padding: clamp(1.6rem, 2.6vw, 2.4rem);
  transition: background .3s var(--ease);
}
.practice-card:hover { background: var(--navy-800); }
.practice-index {
  font-family: var(--font-display); font-size: 0.95rem; color: var(--brass-soft);
  font-weight: 500; letter-spacing: 0.05em;
}
.practice-card h3 {
  font-family: var(--font-display); font-size: 1.5rem; color: #F5F1E7;
  margin-top: 0.9rem; font-weight: 500;
}
.practice-card p {
  margin-top: 0.7rem; color: rgba(232,228,216,.72); font-size: 0.98rem; line-height: 1.6;
}
.practice-more {
  margin-top: 2.2rem; color: rgba(232,228,216,.6); font-size: 0.95rem;
  border-left: 2px solid var(--brass); padding-left: 1rem;
}

/* ============================================================
   PEOPLE
   ============================================================ */
.section-people { background: var(--paper-2); }
.people-list { display: flex; flex-direction: column; gap: 1.25rem; }

.person {
  display: grid; grid-template-columns: auto 1fr; gap: clamp(1.4rem, 3vw, 2.6rem);
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: clamp(1.6rem, 3vw, 2.6rem);
  transition: box-shadow .3s var(--ease), transform .3s var(--ease), border-color .3s var(--ease);
}
.person:hover {
  box-shadow: 0 26px 50px -32px rgba(14,35,64,.4);
  border-color: var(--line-strong);
}

.person-seal {
  width: 76px; height: 76px; flex: none;
  display: grid; place-items: center;
  background: var(--navy); color: var(--brass-soft);
  border-radius: var(--radius);
  box-shadow: inset 0 0 0 1px rgba(201,168,76,.5), inset 0 0 0 5px var(--navy), inset 0 0 0 6px rgba(201,168,76,.28);
}
.person-seal span { font-family: var(--font-display); font-size: 2rem; font-weight: 600; }
.person-seal .seal-initials { font-size: 1.55rem; letter-spacing: 0.03em; }

.person-head {
  display: flex; align-items: baseline; gap: 0.9rem; flex-wrap: wrap;
  padding-bottom: 0.9rem; margin-bottom: 1rem; border-bottom: 1px solid var(--line);
}
.person-name { font-family: var(--font-display); font-size: 1.6rem; color: var(--navy); font-weight: 600; }
.person-role {
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--brass-600);
}
html[data-lang="zh"] .person-role { letter-spacing: 0.2em; }
.person-bio { color: var(--ink-soft); font-size: 1.02rem; line-height: 1.75; max-width: 68ch; }

.person-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.2rem; }
.person-tags li {
  font-size: 0.78rem; font-weight: 500; color: var(--navy-700);
  background: rgba(27,58,107,.07); border: 1px solid rgba(27,58,107,.12);
  padding: 0.3em 0.8em; border-radius: 999px;
}

/* ============================================================
   INSIGHTS
   ============================================================ */
.section-insights { background: var(--paper); }
.insights-inner {
  display: grid; grid-template-columns: 1fr 1fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: center;
}
.insights-lead { margin-top: 1.2rem; color: var(--ink-soft); font-size: 1.08rem; max-width: 42ch; }
.insights-channels { display: flex; flex-direction: column; gap: 1rem; }
.insights-channels li {
  display: grid; gap: 0.35rem;
  background: var(--card); border: 1px solid var(--line);
  border-left: 3px solid var(--brass);
  padding: 1.3rem 1.5rem; border-radius: var(--radius);
}
.channel-kind {
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--brass-600);
}
.channel-name { font-family: var(--font-display); font-size: 1.5rem; color: var(--navy); font-weight: 600; }
.channel-note { font-size: 0.92rem; color: var(--ink-soft); }

/* ============================================================
   CONTACT
   ============================================================ */
.section-contact { background: var(--paper-2); }
.contact-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: start; }
.contact-copy { margin-top: 1.2rem; margin-bottom: 2rem; color: var(--ink-soft); font-size: 1.12rem; max-width: 42ch; }

.contact-details { border-top: 1px solid var(--line-strong); margin-top: 0.5rem; }
.contact-row {
  display: grid; grid-template-columns: 8.5rem 1fr; gap: 1rem;
  padding: 1.1rem 0; border-bottom: 1px solid var(--line);
}
.contact-row dt {
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--brass-600); padding-top: 0.15em;
}
html[data-lang="zh"] .contact-row dt { letter-spacing: 0.2em; }
.contact-row dd { margin: 0; font-size: 1.1rem; color: var(--navy); font-weight: 500; }
.contact-row dd a { border-bottom: 1px solid var(--brass); transition: color .2s var(--ease); }
.contact-row dd a:hover { color: var(--brass-600); }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer { background: var(--navy); color: rgba(232,228,216,.72); }
.footer-inner {
  display: flex; justify-content: space-between; gap: 2rem; flex-wrap: wrap;
  padding-block: clamp(3rem, 6vw, 4.5rem) 2.5rem;
}
.footer-name { font-family: var(--font-display); font-size: 1.3rem; color: #F5F1E7; font-weight: 600; margin-top: 0.7rem; }
.footer-name-zh { font-size: 0.9rem; letter-spacing: 0.2em; color: rgba(232,228,216,.85); margin-top: 2px; }
.footer-tag { font-size: 0.86rem; color: rgba(232,228,216,.55); margin-top: 0.6rem; }

.footer-nav { display: flex; flex-wrap: wrap; gap: 1.4rem; align-content: flex-start; padding-top: 0.6rem; }
.footer-nav a {
  font-size: 0.95rem; color: rgba(232,228,216,.78); transition: color .2s var(--ease);
  position: relative;
}
.footer-nav a:hover { color: var(--brass-soft); }

.footer-legal {
  border-top: 1px solid rgba(255,255,255,.12);
  padding-block: 1.6rem 2.4rem;
  display: flex; justify-content: space-between; gap: 1rem 2rem; flex-wrap: wrap;
  font-size: 0.82rem; color: rgba(232,228,216,.5);
}
.footer-disclaimer { max-width: 62ch; }

/* ============================================================
   REVEAL ANIMATION
   ============================================================ */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.practice-card.reveal { transition-delay: calc(var(--i, 0) * 60ms); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; }
  .about-head { position: static; }
  .practice-grid { grid-template-columns: repeat(2, 1fr); }
  .insights-inner, .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  html { scroll-padding-top: 74px; }
  .header-inner { min-height: 62px; }
  .site-nav {
    position: fixed; inset: 62px 0 auto 0;
    flex-direction: column; align-items: flex-start; gap: 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    padding: 0.5rem var(--gutter) 1.5rem;
    transform: translateY(-120%); transition: transform .35s var(--ease);
    box-shadow: 0 20px 40px -24px rgba(14,35,64,.4);
  }
  .site-nav.open { transform: translateY(0); }
  .site-nav a { width: 100%; padding: 0.9rem 0; border-bottom: 1px solid var(--line); font-size: 1.05rem; }
  .site-nav a::after { display: none; }
  .nav-burger { display: block; }
  .nav-burger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-burger.open span:nth-child(2) { opacity: 0; }
  .nav-burger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .practice-grid { grid-template-columns: 1fr; }
  .person { grid-template-columns: 1fr; }
  .person-seal { width: 64px; height: 64px; }
  .person-seal span { font-size: 1.7rem; }
  .contact-row { grid-template-columns: 1fr; gap: 0.3rem; }
  .footer-legal { flex-direction: column; }
}

/* ============================================================
   ACCESSIBILITY
   ============================================================ */
:focus-visible { outline: 2px solid var(--brass); outline-offset: 3px; border-radius: 2px; }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}