/* ==========================================================================
   Yongshe Trading Limited — global stylesheet (style.css)
   Palette: deep charcoal / coral / warm sand
   ========================================================================== */

:root {
  --bg: #14171c;
  --bg-2: #1a1e25;
  --bg-3: #21262f;
  --bg-4: #292f3a;
  --border: #2c323d;
  --border-soft: #242933;
  --text: #f4f1eb;
  --text-strong: #ffffff;
  --muted: #a3aab6;
  --muted-2: #7d8590;
  --accent: #ff6b57;
  --accent-strong: #ff8468;
  --accent-soft: #572a24;
  --sand: #f2d8b0;
  --radius: 14px;
  --radius-lg: 20px;
  --sidebar-w: 280px;
  --font-head: "Sora", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  color: var(--text-strong);
  line-height: 1.2;
  margin: 0 0 0.5em;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 48px;
}

/* --------------------------------------------------------------------------
   App shell — sidebar grid
   -------------------------------------------------------------------------- */

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: 100vh;
}

.main {
  grid-column: 2;
  min-width: 0;
}

/* --------------------------------------------------------------------------
   Sidebar navigation (fixed, class selector)
   -------------------------------------------------------------------------- */

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  z-index: 50;
  display: flex;
  flex-direction: column;
  background-color: var(--bg-2);
  border-right: 1px solid var(--border);
  padding: 40px 28px 32px;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 48px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 22px;
  color: var(--text-strong);
}

.sidebar-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 11px;
  background-color: var(--accent);
  color: #1a0e0b;
  font-weight: 800;
  font-size: 20px;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sidebar-link {
  position: relative;
  display: block;
  padding: 11px 14px;
  border-radius: 9px;
  color: var(--muted);
  font-weight: 500;
  font-size: 15px;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.sidebar-link:hover {
  color: var(--text-strong);
  background-color: var(--bg-3);
}

.sidebar-link.is-active {
  color: var(--text-strong);
  background-color: var(--accent-soft);
}

.sidebar-link.is-active::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 22px;
  border-radius: 0 3px 3px 0;
  background-color: var(--accent);
}

.sidebar-foot {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 24px;
  border-top: 1px solid var(--border-soft);
}

.sidebar-foot-label {
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted-2);
  margin-bottom: 4px;
}

.sidebar-foot-link {
  color: var(--muted);
  font-size: 14px;
}

.sidebar-foot-link:hover {
  color: var(--accent-strong);
}

.sidebar-overlay {
  display: none;
}

/* --------------------------------------------------------------------------
   Mobile bar
   -------------------------------------------------------------------------- */

.mobile-bar {
  display: none;
}

.sidebar-toggle {
  display: none;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 26px;
  border-radius: 999px;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 15px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.16s ease, background-color 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.btn-primary {
  background-color: var(--accent);
  color: #1a0e0b;
}

.btn-primary:hover {
  background-color: var(--accent-strong);
  transform: translateY(-2px);
}

.btn-ghost {
  background-color: transparent;
  color: var(--text);
  border-color: var(--border);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
  transform: translateY(-2px);
}

/* --------------------------------------------------------------------------
   Section primitives
   -------------------------------------------------------------------------- */

.section-kicker {
  display: inline-block;
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-strong);
  margin: 0 0 16px;
}

.section-head {
  max-width: 760px;
  margin-bottom: 56px;
}

.section-title {
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-sub {
  color: var(--muted);
  font-size: 18px;
  margin: 0;
}

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */

.hero-section {
  position: relative;
  padding: 96px 0 120px;
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--border-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--border-soft) 1px, transparent 1px);
  background-size: 44px 44px;
  overflow: hidden;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 48px;
}

.hero-kicker {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--sand);
  margin: 0 0 20px;
}

.hero-title {
  font-size: clamp(38px, 6vw, 64px);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 28px;
  max-width: 15ch;
}

.hero-lead {
  font-size: 19px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 640px;
  margin: 0 0 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 64px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.hero-stat {
  background-color: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px;
}

.hero-stat-value {
  display: block;
  font-family: var(--font-head);
  font-size: 34px;
  font-weight: 700;
  color: var(--text-strong);
  letter-spacing: -0.02em;
}

.hero-stat-label {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin-top: 4px;
}

/* --------------------------------------------------------------------------
   Manifesto / statement
   -------------------------------------------------------------------------- */

.manifesto-section {
  padding: 120px 0;
  background-color: var(--bg-2);
  border-top: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
}

.manifesto-section .container {
  max-width: 980px;
}

.statement-title {
  font-size: clamp(30px, 4.4vw, 48px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 28px;
}

.statement-body {
  font-size: 19px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 820px;
  margin: 0;
}

/* --------------------------------------------------------------------------
   Method (numbered list)
   -------------------------------------------------------------------------- */

.method-section {
  padding: 120px 0;
  background-color: var(--bg);
}

.method-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.method-item {
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 32px;
  padding: 40px 0;
  border-top: 1px solid var(--border-soft);
}

.method-item:last-child {
  border-bottom: 1px solid var(--border-soft);
}

.method-num {
  font-family: var(--font-head);
  font-size: 46px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.method-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 12px;
}

.method-text {
  color: var(--muted);
  margin: 0;
  max-width: 720px;
}

/* --------------------------------------------------------------------------
   Capabilities
   -------------------------------------------------------------------------- */

.capabilities-section {
  padding: 120px 0;
  background-color: var(--bg-2);
  border-top: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
}

.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.capability {
  background-color: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.capability:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
}

.capability-num {
  display: block;
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 600;
  color: var(--sand);
  margin-bottom: 16px;
}

.capability-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 12px;
}

.capability-text {
  color: var(--muted);
  margin: 0;
}

/* --------------------------------------------------------------------------
   Engagement timeline
   -------------------------------------------------------------------------- */

.engagement-section {
  padding: 120px 0;
  background-color: var(--bg);
}

.timeline {
  position: relative;
  max-width: 780px;
  margin: 0 auto;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background-color: var(--border);
}

.timeline-item {
  position: relative;
  padding-left: 52px;
  padding-bottom: 44px;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: 0;
  top: 8px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: var(--accent);
  box-shadow: 0 0 0 5px var(--accent-soft);
}

.timeline-card {
  background-color: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 28px;
}

.timeline-title {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
}

.timeline-text {
  color: var(--muted);
  margin: 0;
}

/* --------------------------------------------------------------------------
   Principles
   -------------------------------------------------------------------------- */

.principles-section {
  padding: 120px 0;
  background-color: var(--bg-2);
  border-top: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
}

.principles-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.principle {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

.principle-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background-color: var(--bg-3);
  border: 1px solid var(--border);
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 22px;
  color: var(--accent-strong);
}

.principle-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 10px;
}

.principle-text {
  color: var(--muted);
  margin: 0;
  max-width: 760px;
}

/* --------------------------------------------------------------------------
   FAQ
   -------------------------------------------------------------------------- */

.faq-section {
  padding: 120px 0;
  background-color: var(--bg);
}

.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background-color: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 26px;
  background-color: transparent;
  border: none;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-strong);
}

.faq-icon {
  position: relative;
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
}

.faq-icon::before,
.faq-icon::after {
  content: "";
  position: absolute;
  background-color: var(--accent-strong);
  border-radius: 2px;
  transition: transform 0.2s ease;
}

.faq-icon::before {
  left: 0;
  right: 0;
  top: 50%;
  height: 2px;
  transform: translateY(-50%);
}

.faq-icon::after {
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  transform: translateX(-50%);
}

.faq-item.open .faq-icon::after {
  transform: translateX(-50%) scaleY(0);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.open .faq-answer {
  max-height: 320px;
}

.faq-answer p {
  margin: 0;
  padding: 0 26px 24px;
  color: var(--muted);
}

/* --------------------------------------------------------------------------
   Contact
   -------------------------------------------------------------------------- */

.contact-section {
  padding: 120px 0;
  background-color: var(--bg-2);
  border-top: 1px solid var(--border-soft);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
}

.contact-text {
  color: var(--muted);
  font-size: 18px;
  margin: 0 0 32px;
  max-width: 480px;
}

.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.contact-list li {
  color: var(--muted);
  font-size: 16px;
}

.contact-list a {
  color: var(--text-strong);
  font-weight: 500;
}

.contact-list a:hover {
  color: var(--accent-strong);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
  background-color: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.field-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.field input,
.field textarea {
  width: 100%;
  padding: 13px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background-color: var(--bg-2);
  color: var(--text-strong);
  font-family: var(--font-body);
  font-size: 16px;
  transition: border-color 0.16s ease;
}

.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.field textarea {
  resize: vertical;
}

.form-note {
  font-size: 15px;
  color: var(--sand);
  margin: 0;
  min-height: 20px;
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */

.site-footer {
  background-color: var(--bg);
  border-top: 1px solid var(--border-soft);
}

.footer-newsletter {
  padding: 64px 0;
  background-color: var(--bg-2);
  border-bottom: 1px solid var(--border-soft);
}

.newsletter-inner {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
}

.newsletter-title {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 10px;
}

.newsletter-text {
  color: var(--muted);
  margin: 0;
  max-width: 480px;
}

.newsletter-form {
  display: flex;
  gap: 12px;
}

.newsletter-form input {
  flex: 1;
  padding: 14px 18px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background-color: var(--bg-3);
  color: var(--text-strong);
  font-family: var(--font-body);
  font-size: 15px;
}

.newsletter-form input:focus {
  outline: none;
  border-color: var(--accent);
}

.footer-main {
  padding: 64px 0 48px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: 40px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-logo {
  font-family: var(--font-head);
  font-size: 26px;
  font-weight: 700;
  color: var(--text-strong);
  margin-bottom: 8px;
}

.footer-about {
  color: var(--muted);
  font-size: 15px;
  margin: 0;
  max-width: 300px;
}

.footer-heading {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-strong);
  margin-bottom: 8px;
}

.footer-col a,
.footer-col span {
  color: var(--muted);
  font-size: 15px;
}

.footer-col a:hover {
  color: var(--accent-strong);
}

.footer-bottom {
  padding: 24px 0;
  border-top: 1px solid var(--border-soft);
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--muted-2);
  font-size: 14px;
}

/* --------------------------------------------------------------------------
   Scroll reveal
   -------------------------------------------------------------------------- */

.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

@media (max-width: 1024px) {
  .hero-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 900px) {
  :root {
    --sidebar-w: 0px;
  }

  .app-shell {
    display: block;
  }

  .main {
    grid-column: auto;
  }

  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.28s ease;
    width: 280px;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .sidebar-overlay {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 40;
    background: rgba(5, 7, 10, 0.7);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.28s ease;
  }

  .sidebar-overlay.active {
    pointer-events: auto;
  }

  .mobile-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    position: sticky;
    top: 0;
    z-index: 30;
    background-color: var(--bg-2);
    border-bottom: 1px solid var(--border);
  }

  .mobile-bar-brand {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 20px;
    color: var(--text-strong);
  }

  .sidebar-toggle {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 42px;
    height: 42px;
    align-items: center;
    justify-content: center;
    border-radius: 9px;
    border: 1px solid var(--border);
    background-color: var(--bg-3);
    cursor: pointer;
  }

  .sidebar-toggle-bar {
    display: block;
    width: 20px;
    height: 2px;
    background-color: var(--text-strong);
    border-radius: 2px;
  }

  .capabilities-grid {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .newsletter-inner {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 600px) {
  .container,
  .hero-inner {
    padding: 0 24px;
  }

  .hero-section {
    padding: 64px 0 88px;
  }

  .manifesto-section,
  .method-section,
  .capabilities-section,
  .engagement-section,
  .principles-section,
  .faq-section,
  .contact-section {
    padding: 72px 0;
  }

  .hero-stats {
    grid-template-columns: 1fr 1fr;
  }

  .method-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .method-num {
    font-size: 34px;
  }

  .newsletter-form {
    flex-direction: column;
  }

  .footer-bottom-inner {
    flex-direction: column;
  }
}