/* 湖州云乐网络科技有限公司 — 黑白科技扁平化 */
:root {
  --bg: #0a0a0a;
  --bg-elevated: #111111;
  --bg-card: #161616;
  --border: #2a2a2a;
  --text: #f5f5f5;
  --text-muted: #8a8a8a;
  --text-dim: #5c5c5c;
  --accent: #ffffff;
  --max-width: 1120px;
  --header-h: 72px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --transition: 0.25s ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.logo-img {
  display: block;
  height: 40px;
  width: auto;
  max-width: min(220px, 52vw);
  object-fit: contain;
}

.nav-desktop {
  display: flex;
  gap: 2rem;
}

.nav-desktop a {
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color var(--transition);
  position: relative;
}

.nav-desktop a:hover,
.nav-desktop a.active {
  color: var(--accent);
}

.nav-desktop a.active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -4px;
  height: 1px;
  background: var(--accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  width: 44px;
  height: 44px;
  cursor: pointer;
  font-size: 1.25rem;
}

.nav-mobile {
  display: none;
  flex-direction: column;
  padding: 1rem 0 1.5rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
}

.nav-mobile.open {
  display: flex;
}

.nav-mobile a {
  padding: 0.75rem 1rem;
  color: var(--text-muted);
  border-left: 2px solid transparent;
}

.nav-mobile a.active,
.nav-mobile a:hover {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--bg-elevated);
}

/* Hero */
.hero {
  padding: 5rem 0 4rem;
  position: relative;
  overflow: hidden;
}

.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.35;
  mask-image: linear-gradient(to bottom, black 40%, transparent);
  pointer-events: none;
}

.hero-content {
  position: relative;
  max-width: 720px;
}

.hero-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.hero-label::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--text-muted);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.hero p.lead {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 540px;
  margin-bottom: 2rem;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 1.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  font-family: inherit;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  background: #e0e0e0;
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--accent);
}

/* Sections */
.section {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
}

.section-header {
  margin-bottom: 2.5rem;
}

.section-header h2 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.section-header p {
  color: var(--text-muted);
  font-size: 0.95rem;
  max-width: 520px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.card {
  background: var(--bg-card);
  padding: 2rem;
  transition: background var(--transition);
}

.card:hover {
  background: var(--bg-elevated);
}

.card-icon {
  width: 40px;
  height: 40px;
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  margin-bottom: 1.25rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 2rem;
  padding: 3rem 0;
}

.stat-num {
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 0.35rem;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.06em;
}

/* Page hero (inner pages) */
.page-hero {
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.page-hero p {
  color: var(--text-muted);
  max-width: 560px;
}

/* Contact */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.contact-info-block {
  padding: 2rem;
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.contact-info-block h3 {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.contact-item {
  margin-bottom: 1.5rem;
}

.contact-item:last-child {
  margin-bottom: 0;
}

.contact-item dt {
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 0.25rem;
}

.contact-item dd {
  font-size: 0.95rem;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--text-muted);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

.form-note {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Support */
.support-search {
  max-width: 560px;
  margin-bottom: 2.5rem;
}

.support-search input {
  width: 100%;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 0.95rem;
}

.faq-list {
  border: 1px solid var(--border);
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 1.25rem 1.5rem;
  background: var(--bg-card);
  border: none;
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: background var(--transition);
}

.faq-question:hover {
  background: var(--bg-elevated);
}

.faq-question::after {
  content: "+";
  font-size: 1.25rem;
  font-weight: 300;
  color: var(--text-muted);
  flex-shrink: 0;
}

.faq-item.open .faq-question::after {
  content: "−";
}

.faq-answer {
  display: none;
  padding: 0 1.5rem 1.25rem;
  background: var(--bg-card);
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  display: block;
}

.support-channels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-top: 3rem;
}

.support-channel {
  background: var(--bg-card);
  padding: 1.75rem;
}

.support-channel h4 {
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.support-channel p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Footer */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  padding: 2.5rem 0;
  background: var(--bg-elevated);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
}

.footer-legal {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.footer-copy,
.footer-beian {
  font-size: 0.8rem;
  line-height: 1.6;
}

.footer-copy {
  color: var(--text-dim);
}

.footer-beian a {
  font-size: inherit;
  line-height: inherit;
  color: var(--text-dim);
  transition: color var(--transition);
}

.footer-beian a:hover {
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

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

@media (max-width: 768px) {
  .nav-desktop {
    display: none;
  }

  .nav-toggle {
    display: grid;
    place-items: center;
  }

  .contact-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 3rem;
  }
}