* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background: url("images/house.jpg") no-repeat center center fixed;
  background-size: cover;
  color: white;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(0,0,0,0.7); 
  padding: 15px 30px;
  position: sticky;
  top: 0;
  z-index: 1000;
}
.navbar .logo {
  color: #fff;
  font-size: 20px;
  font-weight: bold;
}
.nav-links {
  list-style: none;
  display: flex;
}
.nav-links li {
  margin-left: 20px;
}
.nav-links a {
  color: #fff;
  text-decoration: none;
  transition: color 0.3s;
}
.nav-links a:hover {
  color: #f0a500;
}

.hero-section {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
}
.hero-section .hero-text h1 {
  font-size: 3rem;
  color: white;
  text-shadow: 2px 2px 10px rgba(0,0,0,0.5);
}
.hero-section .hero-text p {
  font-size: 1.2rem;
  margin-top: 10px;
  color: white;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}


.content-section {
  padding: 60px 10%;
}
.content-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  background: rgba(0,0,0,0.6);
  padding: 30px;
  border-radius: 10px;
}
.content-container.reverse {
  flex-direction: row-reverse;
}
.content-image img {
  width: 400px;
  border-radius: 10px;
}
.content-text h2 {
  margin-bottom: 15px;
  font-size: 24px;
  color: #fff;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}
.content-text p {
  font-size: 16px;
  color: #eee;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}


/* services page */

.search-section {
  text-align: center;
  margin: 40px auto;
}
.search-section input {
  padding: 10px;
  width: 250px;
  border: none;
  border-radius: 5px;
}
.search-section button {
  padding: 10px 15px;
  margin-left: 10px;
  border: none;
  background: #f0a500;
  color: #fff;
  border-radius: 5px;
  cursor: pointer;
}
.search-section button:hover {
  background: #cc8400;
}

.video-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 25px;
  max-width: 1100px;   
  margin: 40px auto;
  padding: 0 20px;
}

.video-section {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 12px;
  padding: 20px 25px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  transition: transform 0.2s ease;
}

.video-section:hover {
  transform: translateY(-5px);
}

.video-section h2 {
  margin-bottom: 12px;
  color: #333;
  font-size: 20px;
  border-bottom: 2px solid #f0a500;
  padding-bottom: 5px;
}

.video-list {
  list-style: disc;
  padding-left: 20px;
}

.video-list li {
  margin: 6px 0;
}

.video-list a {
  color: #0077cc;
  font-size: 16px;
  text-decoration: none;
}

.video-list a:hover {
  text-decoration: underline;
  color: #005999;
}

/* Discussion */

.discussion-section {
  max-width: 800px;
  margin: 50px auto;
  padding: 20px;
  background: rgba(255, 255, 255, 0.95);
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
}

.discussion-section h2 {
  text-align: center;
  margin-bottom: 10px;
  color: #333;
}

.discussion-section p {
  text-align: center;
  color: #666;
  margin-bottom: 20px;
}

.discussion-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 30px;
}

.discussion-form input,
.discussion-form textarea {
  padding: 12px;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 15px;
  width: 100%;
}

.discussion-form textarea {
  resize: vertical;
  height: 120px;
}

.discussion-form button {
  align-self: flex-end;
  padding: 10px 18px;
  background: #f0a500;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: 0.3s ease;
}

.discussion-form button:hover {
  background: #cc8400;
}

.message {
  background: #f9f9f9;
  border-left: 4px solid #f0a500;
  padding: 15px;
  margin-bottom: 20px;
  border-radius: 6px;
}

.message h4 {
  margin: 0 0 6px 0;
  color: #333;
  font-size: 16px;
}

.message p {
  margin: 0;
  color: #555;
  font-size: 15px;
}

.replies {
  margin-top: 12px;
  padding-left: 20px; 
  border-left: 2px solid #ddd;
}

.reply {
  background: #fff;
  padding: 10px 12px;
  margin-bottom: 10px;
  border-radius: 6px;
}

.reply h5 {
  margin: 0 0 4px 0;
  font-size: 14px;
  color: #444;
}

.reply p {
  margin: 0;
  font-size: 14px;
  color: #555;
}

.reply-btn {
  margin-top: 10px;
  background: #f0a500;
  color: #fff;
  border: none;
  border-radius: 5px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 14px;
}

.reply-btn:hover {
  background: #cc8400;
}

/* 回复表单样式 */
.reply-form {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 10px;
  padding: 10px;
  background: #fff8e6;
  border-radius: 6px;
}

.reply-form input,
.reply-form textarea {
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 14px;
}

.reply-form textarea {
  resize: vertical;
  height: 60px;
}

.reply-form button {
  align-self: flex-end;
  background: #f0a500;
  color: white;
  border: none;
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
}

.reply-form button:hover {
  background: #cc8400;
}


@media (max-width:400px){
  .content-container{
    flex-direction: column;
  }
  .content-container.reverse{
    flex-direction: column;
  }
  .content-image img{
    width: 90%;
  }
}

/* categories */
.categories-section {
  padding: 60px 10%;
  text-align: center;
}

.categories-section h2 {
  font-size: 32px;
  margin-bottom: 10px;
  color: #333;
}

.categories-section p {
  color: #666;
  margin-bottom: 40px;
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 30px;
  justify-items: center;
}

.category-card {
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  max-width: 320px;
  text-align: left;
}

.category-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.2);
}

.category-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.category-card h3 {
  margin: 15px;
  font-size: 20px;
  color: #333;
}

.category-card p {
  margin: 0 15px 15px;
  color: #555;
}

.category-card .btn {
  display: inline-block;
  margin: 0 15px 20px;
  padding: 8px 16px;
  background: #f0a500;
  color: white;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 500;
  transition: background 0.2s;
}

.category-card .btn:hover {
  background: #cc8400;
}


/* door */
.tutorial-section {
  padding: 60px 10%;
  max-width: 900px;
  margin: 0 auto;
  background: rgba(255, 255, 255, 0.95);
  border-radius: 16px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  margin-top: 50px;
}

.tutorial-section h2 {
  font-size: 30px;
  color: #333;
  margin-bottom: 15px;
  border-bottom: 3px solid #f0a500;
  display: inline-block;
  padding-bottom: 6px;
}

.tutorial-section .intro {
  color: #555;
  font-size: 17px;
  margin-bottom: 30px;
  line-height: 1.7;
}

.tutorial-content {
  display: flex;
  flex-direction: column;
  gap: 30px;
}

.tutorial-step h3 {
  color: #222;
  margin-bottom: 10px;
}

.tutorial-step ul, 
.tutorial-step ol {
  margin-left: 20px;
  color: #444;
  line-height: 1.6;
}

.tutorial-step p {
  color: #555;
  line-height: 1.6;
}

.video-tip a {
  color: #0077cc;
  font-weight: 500;
  text-decoration: none;
}

.video-tip a:hover {
  text-decoration: underline;
  color: #005999;
}