/* Shanghai Tuyunmu Trading Co., Ltd. */
@font-face { font-family: "Archivo"; src: url("fonts/archivo-300.woff2") format("woff2"); font-weight: 300; font-style: normal; font-display: swap; }
@font-face { font-family: "Archivo"; src: url("fonts/archivo-400.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "Archivo"; src: url("fonts/archivo-500.woff2") format("woff2"); font-weight: 500; font-style: normal; font-display: swap; }

:root {
  --abyss: #03182B;        /* deepest navy, hero and contact */
  --ink: #073B5C;          /* logo navy */
  --ink-light: #0E4D78;
  --paper: #F2F5F7;
  --plate: #FFFFFF;
  --line: #D3DBE2;
  --line-dark: rgba(255, 255, 255, 0.14);
  --text: #1F3344;
  --muted: #5B6F80;
  --brass: #B5975B;        /* the brass fittings inside the pod */
  --on-dark: #F4F7FA;
  --on-dark-muted: #A7BBCB;
  --cjk: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", "Noto Sans CJK SC";
  --font: "Archivo", var(--cjk), system-ui, sans-serif;
  --wrap: 1240px;
  --gutter: clamp(16px, 4vw, 48px);
  --section: clamp(80px, 11vw, 150px);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  font-kerning: normal;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
html:lang(zh-CN) body { font-size: 1rem; line-height: 1.85; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-underline-offset: 0.2em; }
p { margin: 0; }
h1, h2, h3 { margin: 0; text-wrap: balance; }
h1, h2 { font-weight: 300; letter-spacing: -0.02em; }
html:lang(zh-CN) :is(h1, h2, h3, .entry h3, .why dt) { letter-spacing: 0.02em; word-break: keep-all; overflow-wrap: anywhere; }
:focus-visible { outline: 2px solid var(--brass); outline-offset: 4px; }

.wrap { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }

.skip { position: absolute; left: 12px; top: -60px; z-index: 30; background: var(--on-dark); color: var(--ink); padding: 10px 14px; text-decoration: none; }
.skip:focus { top: 12px; }

/* Deep section: header + hero share one dark field lit from the upper right */
.deep {
  color: var(--on-dark);
  background:
    radial-gradient(70% 80% at 82% 20%, rgba(14, 77, 120, 0.85) 0%, rgba(14, 77, 120, 0) 60%),
    linear-gradient(180deg, #03182B 0%, #052A47 100%);
  overflow-x: clip;
}

/* Header */
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; min-height: 92px; }
.brand { display: flex; align-items: center; gap: 14px; color: var(--on-dark); text-decoration: none; min-width: 0; }
.brand img { width: 76px; flex: none; }
.brand-names { display: flex; flex-direction: column; line-height: 1.25; min-width: 0; }
.brand-primary { font-weight: 500; font-size: 1.0625rem; letter-spacing: 0.005em; word-break: keep-all; }
.brand-secondary { font-size: 0.8125rem; color: var(--on-dark-muted); }
.site-nav { display: flex; align-items: center; gap: clamp(18px, 2.8vw, 40px); font-weight: 400; font-size: 1rem; }
.site-nav a { color: var(--on-dark-muted); text-decoration: none; padding-block: 6px; white-space: nowrap; transition: color 0.2s; }
.site-nav a:hover { color: var(--on-dark); }
.site-nav .lang-switch { color: var(--on-dark); border: 1px solid var(--line-dark); border-radius: 999px; padding: 6px 14px; }
.site-nav .lang-switch:hover { border-color: var(--on-dark); }

/* Hero */
.hero { padding-top: clamp(40px, 7vw, 96px); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 14fr) minmax(0, 10fr); gap: clamp(24px, 4vw, 56px); align-items: center; }
.hero h1 { font-size: clamp(2.75rem, 1.2rem + 4vw, 4.5rem); line-height: 1.02; color: var(--on-dark); }
html:lang(zh-CN) .hero h1 { font-size: clamp(2.125rem, 1.1rem + 3.1vw, 3.75rem); line-height: 1.24; }
.lead { margin-top: 32px; max-width: 32em; font-size: 1.125rem; line-height: 1.65; color: var(--on-dark-muted); font-weight: 300; }
html:lang(zh-CN) .lead { font-size: 1.0625rem; line-height: 1.9; font-weight: 400; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 40px; }
.btn {
  display: inline-flex; align-items: center; min-height: 50px; padding: 0 22px;
  border: 1px solid var(--on-dark); border-radius: 2px;
  font-weight: 500; font-size: 0.9375rem; text-decoration: none; line-height: 1.2; letter-spacing: 0.01em;
  transition: background-color 0.2s, color 0.2s, border-color 0.2s;
}
.btn-primary { background: var(--on-dark); color: var(--ink); }
.btn-primary:hover { background: #FFFFFF; }
.btn-secondary { color: var(--on-dark); border-color: rgba(255, 255, 255, 0.45); }
.btn-secondary:hover { border-color: var(--on-dark); background: rgba(255, 255, 255, 0.06); }
.hero-figure { margin: 0; position: relative; }
.hero-figure img { width: 160%; max-width: none; margin: -12% 0 -12% -19%; }

/* Facts strip */
.facts {
  margin: clamp(56px, 8vw, 112px) 0 0;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line-dark);
}
.facts div { padding: 22px 28px 0 0; }
.facts div + div { padding-left: 28px; border-left: 1px solid var(--line-dark); }
.facts dt { font-size: 0.8125rem; color: var(--on-dark-muted); margin-bottom: 4px; }
.facts dd { margin: 0; font-size: 1.125rem; font-weight: 400; color: var(--on-dark); }

/* The meander band, drawn from the logo's 回纹, engraved in brass */
.fret { display: flex; justify-content: center; overflow: hidden; height: 14px; color: var(--brass); opacity: 0.7; }
.fret svg { flex: none; height: 14px; width: auto; }
.hero .fret { margin-top: clamp(40px, 6vw, 72px); }
.contact .fret { margin-bottom: 0; }

/* One orchestrated reveal on load; nothing else moves on its own */
@media (prefers-reduced-motion: no-preference) {
  .reveal { opacity: 0; transform: translateY(14px); animation: reveal 1s cubic-bezier(0.2, 0.7, 0.2, 1) forwards; }
  .reveal-1 { animation-delay: 0.08s; }
  .reveal-2 { animation-delay: 0.24s; }
  .reveal-3 { animation-delay: 0.4s; }
  .reveal-4 { animation-delay: 0.56s; }
  .hero-figure img { animation: float 10s ease-in-out 1.2s infinite; }
  .fret-draw path {
    stroke-dasharray: 1; stroke-dashoffset: 1;
    animation: fret-draw 0.8s cubic-bezier(0.45, 0, 0.2, 1) both;
    animation-delay: calc(var(--i) * 16ms + 700ms);
  }
}
@keyframes reveal { to { opacity: 1; transform: none; } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-9px); } }
@keyframes fret-draw { 0% { stroke-dashoffset: 1; opacity: 0; } 1% { opacity: 1; } 100% { stroke-dashoffset: 0; opacity: 1; } }

/* Sections */
.section { padding-block: var(--section); }
.section h2 { font-size: clamp(2.125rem, 1.4rem + 2.4vw, 3.5rem); line-height: 1.06; color: var(--ink); }
html:lang(zh-CN) .section h2 { line-height: 1.3; }
.section-head { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 16px 48px; align-items: end; margin-bottom: clamp(32px, 5vw, 64px); }
.section-head p { color: var(--muted); max-width: 34em; font-size: 1.125rem; }

/* Catalogue entries */
.catalog { border-top: 1px solid var(--line); }
.entry { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 32px 48px; align-items: center; padding: clamp(32px, 4vw, 56px) 0; border-bottom: 1px solid var(--line); }
.entry h3 { font-weight: 300; font-size: clamp(1.625rem, 1.1rem + 1.6vw, 2.5rem); line-height: 1.12; letter-spacing: -0.015em; color: var(--ink); }
html:lang(zh-CN) .entry h3 { font-size: clamp(1.5rem, 1.1rem + 1.3vw, 2.125rem); line-height: 1.35; }
.entry p { margin-top: 16px; color: var(--muted); max-width: 30em; }
.plate { margin: 0; }
.plate img, .plate .diagram {
  display: block; width: 100%; height: auto; aspect-ratio: 3 / 2; object-fit: contain; padding: 7%;
  background: radial-gradient(90% 80% at 50% 28%, #FFFFFF 0%, #EEF2F5 55%, #DFE6EC 100%);
}
.plate img { filter: drop-shadow(0 22px 26px rgba(7, 59, 92, 0.22)); }
.plate .diagram { padding: 5% 6%; }
.plate figcaption { margin-top: 12px; font-size: 0.875rem; color: var(--muted); }

/* Technical drawings */
.diagram .ink { fill: none; stroke: var(--ink); stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.diagram .sig { stroke: var(--brass); }
.diagram .dash { stroke-dasharray: 4 5; }
.diagram .hatch { stroke-width: 0.8; opacity: 0.6; }
.diagram .labels text { font: 500 12.5px var(--font); fill: var(--muted); }
.diagram .labels .lead { fill: none; stroke: var(--muted); stroke-width: 0.9; stroke-dasharray: 2 3; }

/* Services */
.services { background: var(--plate); border-block: 1px solid var(--line); }
.steps { list-style: none; margin: clamp(40px, 6vw, 72px) 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 40px; counter-reset: step; }
.steps li { counter-increment: step; position: relative; padding-top: 28px; border-top: 1px solid var(--line); }
.steps li::before {
  content: counter(step); position: absolute; top: -0.6em; left: 0; padding-right: 10px; background: var(--plate);
  font-weight: 500; font-size: 0.8125rem; line-height: 1.2; color: var(--brass); letter-spacing: 0.04em;
}
.steps h3 { font-weight: 400; font-size: 1.3125rem; line-height: 1.25; color: var(--ink); margin-bottom: 12px; }
.steps p { color: var(--muted); }

/* Why */
.why-grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 32px 48px; align-items: start; }
.why h2 { max-width: 16em; }
.why dl { margin: 0; display: grid; gap: 28px; padding-top: 10px; border-top: 1px solid var(--line); }
.why dl div { padding-top: 18px; }
.why dl div + div { border-top: 1px solid var(--line); }
.why dt { font-weight: 400; font-size: 1.3125rem; line-height: 1.25; color: var(--ink); }
.why dd { margin: 6px 0 0; color: var(--muted); }

/* Contact */
.contact { background: var(--abyss); color: var(--on-dark); padding-block: 0 var(--section); }
.contact h2 { font-size: clamp(2.125rem, 1.4rem + 2.4vw, 3.5rem); line-height: 1.06; color: var(--on-dark); }
.contact :focus-visible { outline-color: var(--brass); }
.contact-grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 48px; padding-top: clamp(64px, 9vw, 120px); }
.contact-lead { margin: 18px 0 32px; max-width: 30em; color: var(--on-dark-muted); font-weight: 300; font-size: 1.125rem; }
.contact-email {
  display: inline-block; font-weight: 300; letter-spacing: -0.02em;
  font-size: clamp(2rem, 1rem + 3.6vw, 4.25rem); line-height: 1.1;
  color: var(--on-dark); text-decoration: none; overflow-wrap: anywhere;
  border-bottom: 1px solid var(--brass); padding-bottom: 0.08em; transition: border-color 0.2s;
}
.contact-email:hover { border-bottom-color: var(--on-dark); }
.contact-details { margin: 0; display: grid; gap: 22px; align-content: start; padding-top: 12px; }
.contact-details dt { font-size: 0.8125rem; color: var(--on-dark-muted); margin-bottom: 4px; }
.contact-details dd { margin: 0; font-size: 1.125rem; line-height: 1.5; font-weight: 300; }
.contact-details a { color: var(--on-dark); }
.addr { display: block; }
.addr + .addr { margin-top: 2px; color: var(--on-dark-muted); }

.site-footer { background: var(--abyss); color: var(--on-dark-muted); border-top: 1px solid var(--line-dark); font-size: 0.875rem; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px; padding-block: 24px; }
.site-footer a { color: var(--on-dark); }

/* 404 */
.notfound-inner { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; gap: 16px; }
.notfound h1 { font-size: 2.5rem; margin-top: 16px; color: var(--ink); }

/* Responsive */
@media (max-width: 1439px) {
  .hero-figure img { width: 128%; margin: -9% 0 -9% -12%; }
}
@media (max-width: 900px) {
  .hero-grid, .section-head, .why-grid, .contact-grid, .entry { grid-template-columns: 1fr; }
  .hero-figure { margin-top: 8px; }
  .hero-figure img { width: 118%; margin: -6% 0 -6% -9%; }
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .entry-text { order: 1; }
  .plate { order: 2; }
}
@media (max-width: 720px) {
  .header-inner { min-height: 72px; }
  .brand { gap: 10px; }
  .brand img { width: 58px; }
  .brand-primary { font-size: 0.9375rem; }
  .brand-secondary { display: none; }
  .site-nav a[href="#products"], .site-nav a[href="#services"] { display: none; }
  .facts { grid-template-columns: 1fr; border-top: 0; }
  .facts div, .facts div + div { padding: 14px 0; border-left: 0; border-top: 1px solid var(--line-dark); }
  .facts div { display: flex; justify-content: space-between; gap: 16px; align-items: baseline; }
  .facts dt { margin: 0; }
}
@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; gap: 0; }
  .steps li { padding: 22px 0 26px 44px; border-top: 1px solid var(--line); }
  .steps li:first-child { border-top-color: var(--ink); }
  .steps li::before { top: 24px; left: 0; padding: 0; background: none; }
  .actions .btn { width: 100%; justify-content: center; }
}
@media (max-width: 400px) {
  .site-nav a[href="#contact"] { display: none; }
}