/* ===================================================================
   千问官网 · 明式家具风 核心样式规范
   主色黄花梨 #B8860B · 辅色紫檀 #4A2C2A · 点缀铜件金 #C9A227 · 背景绢米 #F5F0E1
   线条简练如圈椅扶手 · 榫卯咬合与木纹光泽流动
   =================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;600;700;900&display=swap');

:root {
  --color-huanghuali: #B8860B;         /* 主色：黄花梨木色 */
  --color-huanghuali-dark: #8C5F08;    /* 深黄花梨 */
  --color-huanghuali-light: #D4A738;   /* 浅金黄花梨 */
  --color-zitan: #4A2C2A;              /* 辅色：紫檀木色 */
  --color-zitan-deep: #2F1918;         /* 乌沉深紫檀 */
  --color-brass-gold: #C9A227;         /* 点缀：明式铜活件金 */
  --color-brass-bright: #E2B93D;       /* 白铜/黄铜高光 */
  --color-silk-beige: #F5F0E1;         /* 背景：温润绢米色 */
  --color-silk-card: #FAF6ED;          /* 卡片背景绢白 */
  --color-wood-grain: rgba(184, 134, 11, 0.08); /* 柔和木质纹理 */
  --color-text-main: #2A1810;          /* 主文字：深紫檀木色 */
  --color-text-muted: #5C4033;         /* 次级文字：老木棕 */
  --color-border-wood: rgba(74, 44, 42, 0.22); /* 紫檀线脚细框 */
  --color-border-gold: rgba(201, 162, 39, 0.45); /* 铜活金边 */
  
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --shadow-mortise: 0 8px 24px rgba(74, 44, 42, 0.08);
  --shadow-mortise-hover: 0 16px 36px rgba(74, 44, 42, 0.16);
  --radius-quanyi: 18px 4px 18px 4px;  /* 圈椅扶手线条美学 */
  --transition-mortise: all 0.35s cubic-bezier(0.25, 1, 0.5, 1);
}

/* 全局重置与绢米纸底 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-serif);
  background-color: var(--color-silk-beige);
  color: var(--color-text-main);
  line-height: 1.8;
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  /* 绢丝米底细微暗纹 */
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(184, 134, 11, 0.03) 0%, transparent 40%),
    radial-gradient(circle at 90% 80%, rgba(74, 44, 42, 0.04) 0%, transparent 50%),
    linear-gradient(rgba(245, 240, 225, 0.94), rgba(245, 240, 225, 0.94));
}

/* 木纹流光遮罩动效 */
.wood-sheen-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  background: linear-gradient(
    115deg,
    transparent 0%,
    rgba(226, 185, 61, 0.03) 30%,
    rgba(255, 255, 255, 0.08) 50%,
    rgba(201, 162, 39, 0.03) 70%,
    transparent 100%
  );
  background-size: 250% 250%;
  animation: woodSheenSweep 16s ease-in-out infinite alternate;
}

@keyframes woodSheenSweep {
  0% { background-position: 0% 0%; }
  100% { background-position: 100% 100%; }
}

/* 版心容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* 顶部导航 — 圈椅扶手起线、紫檀木骨与铜活扣 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245, 240, 225, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 2px solid var(--color-zitan);
  box-shadow: 0 4px 16px rgba(74, 44, 42, 0.06);
}

.site-header::after {
  content: "";
  display: block;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-brass-gold), transparent);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: var(--color-zitan);
}

.logo-wrapper {
  position: relative;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-silk-card);
  border: 2px solid var(--color-huanghuali);
  box-shadow: 0 2px 8px rgba(74, 44, 42, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-wrapper img {
  width: 36px;
  height: 36px;
  object-fit: contain;
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: 1.5px;
  color: var(--color-zitan);
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand-tag {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--color-zitan);
  color: var(--color-brass-bright);
  border-radius: 3px;
  border: 1px solid var(--color-brass-gold);
  font-weight: 600;
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 6px;
  align-items: center;
}

.nav-links li a {
  text-decoration: none;
  color: var(--color-text-main);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 4px;
  position: relative;
  transition: var(--transition-mortise);
}

.nav-links li a:hover,
.nav-links li a.active {
  color: var(--color-huanghuali-dark);
  background: rgba(184, 134, 11, 0.12);
}

.nav-links li a.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--color-huanghuali);
}

/* 榫卯装饰印记小徽标 */
.mortise-joint-icon {
  display: inline-block;
  width: 14px;
  height: 14px;
  margin-right: 6px;
  vertical-align: middle;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23B8860B'%3E%3Cpath d='M3 3h8v6H7v4h4v8H3zm10 0h8v18h-8v-6h4v-6h-4z'/%3E%3C/svg%3E");
  background-size: contain;
  background-repeat: no-repeat;
}

/* 明式家具四角铜包角（铜件装饰元素） */
.brass-corner-card {
  position: relative;
}

.brass-corner-card::before,
.brass-corner-card::after {
  content: "";
  position: absolute;
  width: 12px;
  height: 12px;
  border-color: var(--color-brass-gold);
  border-style: solid;
  pointer-events: none;
  transition: var(--transition-mortise);
}

.brass-corner-card::before {
  top: 4px;
  left: 4px;
  border-width: 2px 0 0 2px;
}

.brass-corner-card::after {
  bottom: 4px;
  right: 4px;
  border-width: 0 2px 2px 0;
}

.brass-corner-card:hover::before,
.brass-corner-card:hover::after {
  border-color: var(--color-huanghuali);
  width: 16px;
  height: 16px;
}

/* Hero 首屏与零滚动下载区 */
.hero-section {
  padding: 44px 0 36px;
  text-align: center;
  position: relative;
}

.hero-tagline-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 20px;
  background: rgba(74, 44, 42, 0.06);
  border: 1px solid var(--color-border-wood);
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-zitan);
  margin-bottom: 20px;
  letter-spacing: 1px;
}

.hero-tagline-pill .wood-chip {
  color: var(--color-huanghuali);
  font-size: 1.1rem;
}

.hero-title {
  font-size: 2.3rem;
  font-weight: 900;
  color: var(--color-zitan);
  line-height: 1.35;
  margin-bottom: 14px;
  letter-spacing: 1.5px;
}

.hero-subtitle {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--color-huanghuali-dark);
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.hero-desc {
  max-width: 820px;
  margin: 0 auto 36px;
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* 并列 4 个下载入口（零滚动转化） */
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 10px;
}

.download-card {
  background: var(--color-silk-card);
  border: 1px solid var(--color-border-wood);
  border-radius: var(--radius-quanyi);
  padding: 24px 20px;
  text-align: center;
  box-shadow: var(--shadow-mortise);
  transition: var(--transition-mortise);
  position: relative;
  overflow: hidden;
}

/* 榫卯咬合拼接线视觉装饰 */
.download-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-zitan), var(--color-huanghuali), var(--color-brass-gold));
}

.download-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-mortise-hover);
  border-color: var(--color-huanghuali);
}

.download-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 16px;
  border-radius: 12px 2px 12px 2px;
  background: linear-gradient(135deg, var(--color-silk-beige), #EDE4CE);
  border: 1px solid var(--color-border-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--color-huanghuali-dark);
}

.download-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-zitan);
  margin-bottom: 8px;
}

.download-desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 18px;
  min-height: 40px;
}

.btn-ming {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 10px 16px;
  font-size: 0.92rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-decoration: none;
  border-radius: 6px;
  transition: var(--transition-mortise);
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-ming-primary {
  background: linear-gradient(135deg, var(--color-huanghuali) 0%, var(--color-huanghuali-dark) 100%);
  color: #FFF9ED;
  border-color: var(--color-huanghuali-dark);
  box-shadow: 0 4px 12px rgba(184, 134, 11, 0.25);
}

.btn-ming-primary:hover {
  background: linear-gradient(135deg, var(--color-huanghuali-light) 0%, var(--color-huanghuali) 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(184, 134, 11, 0.35);
}

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

.btn-ming-outline:hover {
  background: rgba(74, 44, 42, 0.08);
  border-color: var(--color-zitan);
}

/* 模块通用分割与版式 */
.section {
  padding: 80px 0;
  position: relative;
}

.section-wood-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.divider-line {
  flex: 1;
  max-width: 180px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border-wood), transparent);
}

.mortise-emblem {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-brass-gold);
  letter-spacing: 2px;
  padding: 4px 14px;
  border: 1px solid var(--color-border-wood);
  border-radius: 4px;
  background: var(--color-silk-card);
}

/* 四大功能模块版式统一：
   模块名 + 情绪化短标题 + 场景化功能点
   配明式家具圈椅扶手弧度、榫卯拼接插接图框与插图展示
*/
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 70px;
  background: var(--color-silk-card);
  border: 1px solid var(--color-border-wood);
  border-radius: var(--radius-quanyi);
  padding: 48px;
  box-shadow: var(--shadow-mortise);
  transition: var(--transition-mortise);
  position: relative;
}

.feature-block:hover {
  box-shadow: var(--shadow-mortise-hover);
  border-color: var(--color-huanghuali);
}

.feature-block.reversed {
  direction: rtl;
}

.feature-block.reversed > * {
  direction: ltr;
}

.feature-content {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.feature-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--color-huanghuali-dark);
  margin-bottom: 12px;
}

.feature-name {
  font-size: 1.85rem;
  font-weight: 900;
  color: var(--color-zitan);
  margin-bottom: 8px;
  letter-spacing: 1px;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-huanghuali);
  margin-bottom: 24px;
  position: relative;
  padding-bottom: 12px;
}

.feature-title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 2px;
  background: var(--color-brass-gold);
}

.feature-points {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.feature-points li {
  position: relative;
  padding-left: 28px;
  font-size: 1rem;
  color: var(--color-text-main);
  line-height: 1.7;
}

.feature-points li::before {
  content: "◆";
  position: absolute;
  left: 0;
  top: 1px;
  color: var(--color-huanghuali);
  font-size: 0.85rem;
}

.feature-points strong {
  color: var(--color-zitan);
  font-weight: 700;
}

/* 明式家具框图插图展示框（榫卯画框效果） */
.ming-frame-container {
  position: relative;
  padding: 16px;
  background: linear-gradient(135deg, #3C2220 0%, #2A1715 100%);
  border-radius: var(--radius-quanyi);
  border: 3px solid var(--color-brass-gold);
  box-shadow: 0 12px 28px rgba(74, 44, 42, 0.25);
  display: flex;
  justify-content: center;
  align-items: center;
}

/* 边角铜件铆钉效果 */
.ming-frame-container::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 6px;
  right: 6px;
  bottom: 6px;
  border: 1px dashed rgba(201, 162, 39, 0.5);
  pointer-events: none;
  border-radius: 12px 2px 12px 2px;
}

.ming-frame-image {
  width: 100%;
  max-width: 440px;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 10px 2px 10px 2px;
  display: block;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  transition: var(--transition-mortise);
}

.feature-block:hover .ming-frame-image {
  transform: scale(1.02);
}

/* 网页版入口零安装兜底横幅 */
.web-fallback-section {
  padding: 30px 0 80px;
}

.web-fallback-banner {
  background: linear-gradient(135deg, var(--color-zitan) 0%, var(--color-zitan-deep) 100%);
  border: 2px solid var(--color-brass-gold);
  border-radius: var(--radius-quanyi);
  padding: 48px;
  color: #FFF9ED;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
  box-shadow: var(--shadow-mortise-hover);
  position: relative;
  overflow: hidden;
}

.web-fallback-banner::before {
  content: "";
  position: absolute;
  right: -50px;
  bottom: -50px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, rgba(201, 162, 39, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.web-fallback-info {
  flex: 1;
}

.web-fallback-tag {
  display: inline-block;
  font-size: 0.82rem;
  letter-spacing: 1.5px;
  color: var(--color-brass-bright);
  border: 1px solid var(--color-brass-gold);
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 12px;
}

.web-fallback-title {
  font-size: 1.8rem;
  font-weight: 900;
  color: #FFF9ED;
  margin-bottom: 12px;
  letter-spacing: 1px;
}

.web-fallback-desc {
  font-size: 1rem;
  color: #E2D7C5;
  line-height: 1.7;
}

.web-fallback-action {
  flex-shrink: 0;
}

.btn-gold-large {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  background: linear-gradient(135deg, #D4A738 0%, var(--color-brass-gold) 100%);
  color: var(--color-zitan-deep);
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 1px;
  text-decoration: none;
  border-radius: 6px;
  border: 1px solid var(--color-brass-bright);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.3);
  transition: var(--transition-mortise);
}

.btn-gold-large:hover {
  background: linear-gradient(135deg, #E2B93D 0%, #C9A227 100%);
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(201, 162, 39, 0.4);
}

/* 网页版 web.html 专用样式 */
.chat-demo-frame {
  background: var(--color-silk-card);
  border: 2px solid var(--color-border-wood);
  border-radius: var(--radius-quanyi);
  padding: 36px;
  box-shadow: var(--shadow-mortise);
  max-width: 860px;
  margin: 0 auto 50px;
  position: relative;
}

.chat-input-wrapper {
  display: flex;
  gap: 12px;
}

.chat-input-box {
  flex: 1;
  padding: 14px 18px;
  font-family: var(--font-serif);
  font-size: 1rem;
  border: 1px solid var(--color-border-wood);
  border-radius: 6px;
  background: #FFFDF9;
  color: var(--color-text-main);
  outline: none;
  transition: var(--transition-mortise);
}

.chat-input-box:focus {
  border-color: var(--color-huanghuali);
  box-shadow: 0 0 0 3px rgba(184, 134, 11, 0.15);
}

.step-flow-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 40px;
}

.step-card {
  background: var(--color-silk-card);
  border: 1px solid var(--color-border-wood);
  border-radius: var(--radius-quanyi);
  padding: 28px 24px;
  box-shadow: var(--shadow-mortise);
  transition: var(--transition-mortise);
}

.step-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-huanghuali);
}

.step-num {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--color-huanghuali);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.step-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-zitan);
  margin-bottom: 8px;
}

.step-desc {
  font-size: 0.92rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* 帮助中心 help.html 专用样式 */
.faq-grid {
  display: flex;
  flex-direction: column;
  gap: 20px;
  max-width: 920px;
  margin: 0 auto;
}

.faq-card {
  background: var(--color-silk-card);
  border: 1px solid var(--color-border-wood);
  border-radius: var(--radius-quanyi);
  padding: 28px 32px;
  box-shadow: var(--shadow-mortise);
  transition: var(--transition-mortise);
}

.faq-card:hover {
  border-color: var(--color-huanghuali);
  box-shadow: var(--shadow-mortise-hover);
}

.faq-question {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--color-zitan);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-answer {
  font-size: 0.98rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

/* 页脚 — 紫檀温润底、明式铜合页线脚 */
.site-footer {
  background: var(--color-zitan-deep);
  color: #EDE4CE;
  padding: 48px 0 32px;
  border-top: 3px solid var(--color-brass-gold);
  margin-top: 40px;
}

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 24px;
  list-style: none;
  margin-bottom: 24px;
}

.footer-nav a {
  color: #E2D7C5;
  text-decoration: none;
  font-size: 0.95rem;
  transition: var(--transition-mortise);
}

.footer-nav a:hover {
  color: var(--color-brass-bright);
}

.footer-copy {
  text-align: center;
  font-size: 0.88rem;
  color: #B5A492;
  line-height: 1.8;
}

/* 响应式断点 */
@media (max-width: 992px) {
  .download-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .feature-block {
    grid-template-columns: 1fr;
    gap: 36px;
    padding: 36px 28px;
  }
  
  .feature-block.reversed {
    direction: ltr;
  }
  
  .web-fallback-banner {
    flex-direction: column;
    text-align: center;
    padding: 36px 24px;
  }
  
  .step-flow-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-inner {
    flex-direction: column;
    height: auto;
    padding: 14px 0;
    gap: 12px;
  }
  
  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 4px;
  }
  
  .hero-title {
    font-size: 1.65rem;
  }
  
  .hero-subtitle {
    font-size: 1.15rem;
  }
  
  .download-grid {
    grid-template-columns: 1fr;
  }
  
  .chat-input-wrapper {
    flex-direction: column;
  }
}