/* ========================================
   🌱 基础重置 + 全局字体
======================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Noto Sans SC", sans-serif;
  font-weight: 300;
  line-height: 1.6;
  color: #fff;
  background-color: #000;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   🔠 标题与段落
======================================== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 500;
  letter-spacing: -0.02em;
}

p {
  font-weight: 300;
  letter-spacing: 0.01em;
}

/* ========================================
   📱 Section布局（默认隐藏 + 激活样式）
======================================== */
section {
  display: none;
  flex-direction: column; /* 默认移动端纵向 */
}

section.active {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  width: 100%;
  min-height: 100vh;
  transition: all 0.4s ease;
}

/* ========================================
   📦 Section内容容器
======================================== */
.section-body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 100%;
}

/* ========================================
   🖼 Sketch 区块
======================================== */
.sketch-container {
  background-color: #000;
  color: #fff;
  font-size: 1.2rem;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  min-height: 50vh;
}
.sketch-container iframe {
  width: 500px;
  height: 500px;
  border: none;
}
.sketch-container .iframe-plus {
    width: 100%;
  height: 100%;
}
#sketch-container-14 img{
 width: 200px;
}
/* ========================================
   📝 文本内容区域
======================================== */
.text-content {
  max-width: 600px;
  width: 100%;
  text-align: center;
  line-height: 1.8;
  font-size: 1.1rem;
  padding: 20px 20px;
}

.text-title {
  text-align: center;
  font-size: 2em;
  font-weight: 700;
}

.text-title img {
  max-width: 300px;
  height: auto;
  margin-bottom: 25px;
  filter: grayscale(100%);
}

.text-content p {
  margin: 10px 0;
  position: relative;
  padding-left: 30px;
  text-align: left;
}

.text-content p:before {
  content: "";
  position: absolute;
  left: 0;
  top: -10px;
  font-size: 3rem;
  color: rgba(0, 0, 0, 0.1);
}
.link {
  color: #fff;
}
.link:hover {
  color: #000;
  background-color: #fff;
}



/* ========================================
   🖱 按钮导航样式
======================================== */
.section-nav {
  width: 100%;
  max-width: 40%;
  margin: 10px auto;
  display: flex;
  align-items: center;     /* 垂直居中 */
  justify-content: center; /* 水平居中 */
}

.nav-buttons {
  display: flex;
  gap: 20px;
  list-style: none;
  margin: 0;
  padding: 0;
  align-items: center;     /* 垂直居中 */
  justify-content: center; /* 水平居中 */
}

.nav-item button {
  font-size: 1.1rem;
  padding: 8px 20px;
  color: #fff;
  border: 1px solid #fff;
  border-radius: 0;
  background: #000;
  cursor: pointer;
  transition: background 0.3s ease;
}

.nav-item button:hover {
  background: #fff;
  color: #000;
}

/* ========================================
   🖥 PC端适配：左右布局
======================================== */
@media (min-width: 768px) {
  section {
    flex-direction: row;
    padding: 0;
  }

  .section-body {
    width: 50%;
  }

  .sketch-container {
    width: 50%;
    min-height: 100vh;
  }

  .text-content {
    text-align: left;
    font-size: 1rem;
  }

  .text-content p {
    font-size: 1rem;
    padding: 0;
  }

  .nav-btn {
    font-size: 1rem;
    padding: 6px 12px;
  }

  .nav-container {
    flex-direction: column;
    gap: 10px;
  }
}
/* ========================================
   🖥 移动端适配：上下布局
======================================== */
@media (max-width: 768px) {
  section.active {
    flex-direction: column;
    padding: 20px;
  }

  .section-body {
    width: 100%;

  }

  .sketch-container {
    width: 100%;
    min-height: 50vh;
  }

  .text-content {
    width: 100%;
    text-align: center;
    padding: 0 10px;
  }

  .text-content p {
    font-size: 1rem;
    padding-left: 0;
    text-align: left;
  }

  .text-content p:before {
    display: none; /* 移动端隐藏视觉引用符号 */
  }

  .section-nav {
    max-width: 100%;
    flex-direction: row;
    justify-content: space-around;
  }

  .nav-item button {
    padding: 6px 16px;
    font-size: 1rem;
  }
}