/* ===================================================================
   千问官网 · 篆刻印章风 核心样式规范
   主色印泥朱 #D43D2A · 辅色石章灰 #8D8D8D · 点缀田黄 #E8B54A · 背景绢白 #FAF6EF
   白文朱文印章错落钤印 · 寿山石纹理 · 盖章按压交互 · 印蜕浮现
   =================================================================== */

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

:root {
  --color-seal-vermilion: #D43D2A;     /* 主色：印泥朱 / 朱砂红 */
  --color-seal-dark: #A62818;          /* 深朱泥 */
  --color-seal-bright: #E74C3C;        /* 明朱红 */
  --color-stone-gray: #8D8D8D;         /* 辅色：石章灰 */
  --color-stone-deep: #4A4A4A;         /* 深石砚灰 */
  --color-stone-dark: #2F2F2F;         /* 墨石黑 */
  --color-tianhuang: #E8B54A;          /* 点缀：田黄石色 */
  --color-tianhuang-light: #F4D06F;    /* 亮田黄 */
  --color-silk-white: #FAF6EF;         /* 背景：温润绢白 */
  --color-stone-card: #F2ECE1;         /* 寿山石卡片底色 */
  --color-text-main: #2A2421;          /* 墨色正文字 */
  --color-text-muted: #6B6158;         /* 灰褐次级字 */
  --color-border-stone: rgba(141, 141, 141, 0.35); /* 石纹细界格 */
  --color-border-seal: rgba(212, 61, 42, 0.45);   /* 朱泥印框 */
  
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  
  --shadow-stone: 0 8px 24px rgba(74, 74, 74, 0.08);
  --shadow-stone-hover: 0 16px 36px rgba(212, 61, 42, 0.16);
  --shadow-seal-stamp: 0 6px 18px rgba(212, 61, 42, 0.3);
  
  --radius-seal: 6px 2px 6px 2px;     /* 金石琢刻古拙微角 */
  --transition-seal: all 0.32s cubic-bezier(0.25, 1, 0.5, 1);
}

/* 全局重置与绢白底色 */
*, *::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-white);
  color: var(--color-text-main);
  line-height: 1.85;
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  /* 绢帛细腻纹理与寿山石斑驳暗影 */
  background-image: 
    radial-gradient(circle at 12% 18%, rgba(232, 181, 74, 0.06) 0%, transparent 40%),
    radial-gradient(circle at 88% 82%, rgba(212, 61, 42, 0.05) 0%, transparent 45%),
    linear-gradient(rgba(250, 246, 239, 0.96), rgba(250, 246, 239, 0.96));
}

/* 印泥印蜕背景漂浮钤印层 */
.seal-stamp-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  background: radial-gradient(circle at 50% 50%, rgba(232, 181, 74, 0.03) 0%, transparent 60%);
}

/* 白文朱文印章错落装饰 */
.seal-watermark {
  position: absolute;
  pointer-events: none;
  font-weight: 900;
  user-select: none;
  z-index: 0;
  opacity: 0.12;
  letter-spacing: 2px;
  border-style: solid;
  writing-mode: vertical-rl;
  text-orientation: upright;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 朱文印（阳刻：红框红字） */
.seal-zhuwen {
  border-width: 3px;
  border-color: var(--color-seal-vermilion);
  color: var(--color-seal-vermilion);
  padding: 10px 6px;
  border-radius: 4px;
}

/* 白文印（阴刻：红底白字） */
.seal-baiwen {
  background: var(--color-seal-vermilion);
  color: #FFF;
  border-width: 2px;
  border-color: var(--color-seal-dark);
  padding: 10px 6px;
  border-radius: 3px;
}

/* 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 — 苍劲金石线脚与朱文斋印 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 246, 239, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 2px solid var(--color-seal-vermilion);
  box-shadow: 0 4px 18px rgba(74, 74, 74, 0.06);
}

.site-header::after {
  content: "";
  display: block;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-tianhuang), var(--color-seal-vermilion), 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-text-main);
}

.seal-logo-box {
  position: relative;
  width: 48px;
  height: 48px;
  border-radius: 4px;
  background: var(--color-stone-card);
  border: 2px solid var(--color-seal-vermilion);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 0 6px rgba(212, 61, 42, 0.2);
}

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

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

.brand-tag {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--color-seal-vermilion);
  color: #FFF;
  border-radius: 2px;
  border: 1px solid var(--color-seal-dark);
  font-weight: 700;
  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: 3px;
  position: relative;
  letter-spacing: 0.5px;
  transition: var(--transition-seal);
}

.nav-links li a:hover,
.nav-links li a.active {
  color: var(--color-seal-vermilion);
  background: rgba(212, 61, 42, 0.08);
  border: 1px dashed var(--color-border-seal);
}

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

/* 小印章图标（朱红小方印） */
.mini-seal-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--color-seal-vermilion);
  color: var(--color-seal-vermilion);
  font-size: 0.72rem;
  font-weight: 900;
  margin-right: 6px;
  border-radius: 2px;
  line-height: 1;
}

/* 寿山石质感卡片底 */
.shoushan-card {
  background: var(--color-stone-card);
  border: 1px solid var(--color-border-stone);
  border-radius: var(--radius-seal);
  box-shadow: var(--shadow-stone);
  position: relative;
  transition: var(--transition-seal);
  /* 寿山石温润斑驳石纹 */
  background-image: 
    radial-gradient(circle at 80% 20%, rgba(232, 181, 74, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 20% 80%, rgba(141, 141, 141, 0.06) 0%, transparent 60%);
}

.shoushan-card::before,
.shoushan-card::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  border-color: var(--color-seal-vermilion);
  border-style: solid;
  pointer-events: none;
  transition: var(--transition-seal);
}

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

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

.shoushan-card:hover::before,
.shoushan-card:hover::after {
  width: 14px;
  height: 14px;
  border-color: var(--color-tianhuang);
}

/* 盖章按压按钮交互 */
.btn-seal-stamp {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-decoration: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.18s ease-out;
  border: 2px solid transparent;
  position: relative;
  user-select: none;
}

.btn-seal-primary {
  background: var(--color-seal-vermilion);
  color: #FFF;
  border-color: var(--color-seal-dark);
  box-shadow: 0 4px 12px rgba(212, 61, 42, 0.28);
}

/* 盖章按下顿挫感 */
.btn-seal-primary:hover {
  background: var(--color-seal-bright);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(212, 61, 42, 0.38);
}

.btn-seal-primary:active {
  transform: translateY(2px) scale(0.97);
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.4);
}

.btn-seal-secondary {
  background: var(--color-stone-card);
  color: var(--color-stone-dark);
  border: 1px solid var(--color-stone-gray);
}

.btn-seal-secondary:hover {
  background: #FFF;
  border-color: var(--color-seal-vermilion);
  color: var(--color-seal-vermilion);
}

.btn-seal-secondary:active {
  transform: translateY(2px) scale(0.97);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.2);
}

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

.hero-seal-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 20px;
  background: rgba(212, 61, 42, 0.06);
  border: 1px solid var(--color-border-seal);
  border-radius: 4px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-seal-vermilion);
  margin-bottom: 20px;
  letter-spacing: 1.5px;
}

.hero-title {
  font-size: 2.25rem;
  font-weight: 900;
  color: var(--color-stone-dark);
  line-height: 1.35;
  margin-bottom: 14px;
  letter-spacing: 1.5px;
}

.hero-subtitle {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--color-seal-vermilion);
  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 {
  padding: 24px 20px;
  text-align: center;
  overflow: hidden;
}

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

.download-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 16px;
  border-radius: 4px;
  background: #FFF;
  border: 1px solid var(--color-tianhuang);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--color-seal-vermilion);
  box-shadow: inset 0 0 6px rgba(232, 181, 74, 0.2);
}

.download-name {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-stone-dark);
  margin-bottom: 8px;
}

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

/* 金石刻线分隔符 */
.stone-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-stone-gray), transparent);
}

.seal-tag-center {
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--color-seal-vermilion);
  letter-spacing: 2px;
  padding: 4px 14px;
  border: 1px solid var(--color-border-seal);
  border-radius: 3px;
  background: var(--color-stone-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
   配寿山石质感卡片、朱泥印蜕画框展示
*/
.section {
  padding: 76px 0;
  position: relative;
}

.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 64px;
  padding: 48px;
}

.feature-block:hover {
  border-color: var(--color-seal-vermilion);
  box-shadow: var(--shadow-stone-hover);
}

.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: 800;
  letter-spacing: 1px;
  color: var(--color-seal-vermilion);
  margin-bottom: 12px;
}

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

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-seal-vermilion);
  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-tianhuang);
}

.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-seal-vermilion);
  font-size: 0.78rem;
}

.feature-points strong {
  color: var(--color-stone-dark);
  font-weight: 800;
}

/* 寿山石与朱泥印框容器 */
.seal-frame-container {
  position: relative;
  padding: 16px;
  background: #EAE3D5;
  border-radius: var(--radius-seal);
  border: 3px solid var(--color-seal-vermilion);
  box-shadow: 0 10px 24px rgba(74, 74, 74, 0.15);
  display: flex;
  justify-content: center;
  align-items: center;
}

.seal-frame-container::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 6px;
  right: 6px;
  bottom: 6px;
  border: 1px dashed var(--color-seal-vermilion);
  pointer-events: none;
}

.seal-frame-image {
  width: 100%;
  max-width: 440px;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 4px;
  display: block;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
  transition: var(--transition-seal);
}

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

/* 网页版入口零安装兜底横幅 */
.web-entry-section {
  padding: 24px 0 76px;
}

.web-entry-banner {
  background: linear-gradient(135deg, var(--color-seal-dark) 0%, var(--color-stone-dark) 100%);
  border: 2px solid var(--color-tianhuang);
  border-radius: var(--radius-seal);
  padding: 48px;
  color: #FFF;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 36px;
  box-shadow: var(--shadow-seal-stamp);
  position: relative;
  overflow: hidden;
}

.web-entry-banner::before {
  content: "";
  position: absolute;
  right: -50px;
  bottom: -50px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, rgba(232, 181, 74, 0.2) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

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

.web-entry-tag {
  display: inline-block;
  font-size: 0.82rem;
  letter-spacing: 1.5px;
  color: var(--color-tianhuang-light);
  border: 1px solid var(--color-tianhuang);
  padding: 3px 10px;
  border-radius: 2px;
  margin-bottom: 12px;
}

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

.web-entry-desc {
  font-size: 1rem;
  color: #F0EAE1;
  line-height: 1.7;
}

.btn-tianhuang-large {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 32px;
  background: linear-gradient(135deg, var(--color-tianhuang-light) 0%, var(--color-tianhuang) 100%);
  color: var(--color-stone-dark);
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: 1px;
  text-decoration: none;
  border-radius: 4px;
  border: 1px solid #FFF;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.25);
  transition: var(--transition-seal);
}

.btn-tianhuang-large:hover {
  background: #FFF;
  color: var(--color-seal-vermilion);
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(232, 181, 74, 0.4);
}

/* web.html 网页版在线对话体验专用样式 */
.chat-seal-frame {
  background: var(--color-stone-card);
  border: 2px solid var(--color-seal-vermilion);
  border-radius: var(--radius-seal);
  padding: 36px;
  max-width: 860px;
  margin: 0 auto 50px;
  box-shadow: var(--shadow-stone);
}

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

.chat-seal-input {
  flex: 1;
  padding: 14px 18px;
  font-family: var(--font-serif);
  font-size: 1rem;
  border: 1px solid var(--color-stone-gray);
  border-radius: 4px;
  background: #FFF;
  color: var(--color-text-main);
  outline: none;
  transition: var(--transition-seal);
}

.chat-seal-input:focus {
  border-color: var(--color-seal-vermilion);
  box-shadow: 0 0 0 3px rgba(212, 61, 42, 0.15);
}

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

.step-card {
  padding: 28px 24px;
  transition: var(--transition-seal);
}

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

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

.step-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-stone-dark);
  margin-bottom: 8px;
}

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

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

.faq-card {
  padding: 28px 32px;
  transition: var(--transition-seal);
}

.faq-card:hover {
  border-color: var(--color-seal-vermilion);
  box-shadow: var(--shadow-stone-hover);
}

.faq-question {
  font-size: 1.18rem;
  font-weight: 800;
  color: var(--color-stone-dark);
  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 */
.site-footer {
  background: var(--color-stone-dark);
  color: #EDE4CE;
  padding: 48px 0 32px;
  border-top: 3px solid var(--color-seal-vermilion);
  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-seal);
}

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

.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-entry-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;
  }
}