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

body {
  font-family: "Microsoft YaHei", sans-serif;
  background: #0b0f1a;
  color: #fff;
}

/* Common container */
.container {
  width: 1200px;
  margin: auto;
}

/* Header */
.header {
  background: #0b0f1a;
  border-bottom: 1px solid #1f2a44;
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  font-weight: bold;
}

.menu {
  display: flex;
  list-style: none;
}

.menu li a {
  color: #ccc;
  text-decoration: none;
  margin-left: 24px;
}

.menu li a:hover {
  color: #4da3ff;
}

/* Banner */
.banner {
  height: 280px;
  background: linear-gradient(120deg, #0f2027, #203a43, #2c5364);
  display: flex;
  align-items: center;
  justify-content: center;
}

.banner-content {
  text-align: center;
}

.banner h1 {
  font-size: 40px;
}

.banner p {
  margin-top: 12px;
  color: #ccc;
}

/* Color block cards */
.cards {
  margin-top: -70px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.card-grid a {
  text-decoration: none;
}

.card {
  padding: 20px;
  border-radius: 12px;
  color: #fff;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
  cursor: pointer;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  position: relative;
  overflow: hidden;
  height: 200px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.card h3 {
  height: 3em;
  line-height: 1.5em;
  margin: 0;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.1), rgba(255,255,255,0));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.card:hover::before {
  opacity: 1;
}

.card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

.card h3 {
  text-align: center;
  font-size: 1.2em;
}

.card p {
  text-align: center;
}

.blue { 
  background: linear-gradient(135deg, #667eea, #89b5f5);
}
.blue h3, .blue p, .blue .project-number {
  background: linear-gradient(135deg, #0c1e4a, #1e3a8a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.green { 
  background: linear-gradient(135deg, #89b5f5, #a8edea);
}
.green h3, .green p, .green .project-number {
  background: linear-gradient(135deg, #0c1e4a, #052e3f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.cyan { 
  background: linear-gradient(135deg, #c6ffdd, #ffd89b);
}
.cyan h3, .cyan p, .cyan .project-number {
  background: linear-gradient(135deg, #1a3409, #0f2e1a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.purple { 
  background: linear-gradient(135deg, #ffd89b, #ff6b9d);
}
.purple h3, .purple p, .purple .project-number {
  background: linear-gradient(135deg, #581c87, #9f1239);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Content area */
.content {
  padding: 80px 0;
  background: #0f1629;
}

.content-layout {
  display: grid;
  grid-template-columns: 3fr 1fr;
  gap: 40px;
}

.content-main img {
  width: 100%;
  margin: 20px 0;
}

.content-main h2 {
  font-size: 1.8em;
}

.content-main p {
  margin-bottom: 1.5em;
  line-height: 1.6;
  font-size: 1.1em;
}

.content-side {
  background: #111b33;
  padding: 20px;
  border-radius: 6px;
}

/* Project list */
.project-list {
  padding: 80px 0;
}

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

.project-item {
  background: #111b33;
  border-radius: 6px;
  overflow: hidden;
}

.project-item img {
  width: 100%;
}

.project-item h4 {
  padding: 16px;
}

/* Footer */
.footer {
  background: #050812;
  padding: 30px 0;
  text-align: center;
  color: #666;
}

/* RRR section styles */
.rrr-section {
  background: #2c3e50;
  padding: 80px 0;
  text-align: center;
}

.rrr-section h2 {
  font-size: 40px;
  color: #fff;
  margin-bottom: 40px;
}

.rrr-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 15px;
  max-width: 1200px;
  margin: 0 auto;
}

.rrr-card {
  padding: 15px;
  border-radius: 12px;
  color: #fff;
  text-decoration: none;
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
  cursor: pointer;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  position: relative;
  overflow: hidden;
  min-height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: bold;
}

.rrr-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.1), rgba(255,255,255,0));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.rrr-card:hover::before {
  opacity: 1;
}

.rrr-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

.rrr-blue { 
  background: linear-gradient(135deg, #ff6b9d, #ffa06e); 
}
.rrr-blue h3, .rrr-blue p {
  background: linear-gradient(135deg, #881337, #92400e);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.rrr-green { 
  background: linear-gradient(135deg, #ffa06e, #ffd89b); 
}
.rrr-green h3, .rrr-green p {
  background: linear-gradient(135deg, #92400e, #713f12);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.rrr-cyan { 
  background: linear-gradient(135deg, #ffd89b, #c6ffdd); 
}
.rrr-cyan h3, .rrr-cyan p {
  background: linear-gradient(135deg, #1a3409, #0f2e1a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.rrr-purple { 
  background: linear-gradient(135deg, #c6ffdd, #a8edea); 
}
.rrr-purple h3, .rrr-purple p {
  background: linear-gradient(135deg, #0f2e1a, #052e3f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.rrr-orange { 
  background: linear-gradient(135deg, #a8edea, #89b5f5); 
}
.rrr-orange h3, .rrr-orange p {
  background: linear-gradient(135deg, #052e3f, #0c1e4a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.rrr-pink { 
  background: linear-gradient(135deg, #89b5f5, #667eea); 
}
.rrr-pink h3, .rrr-pink p {
  background: linear-gradient(135deg, #0c1e4a, #1e3a8a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Back button styles */
.back-button {
  display: inline-block;
  padding: 10px 20px;
  background: #4da3ff;
  color: #fff;
  text-decoration: none;
  border-radius: 5px;
  transition: background 0.3s ease, transform 0.3s ease;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.back-button:hover {
  background: #1f78d1;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

/* Fixed navigation styles */
.fixed-nav {
  position: fixed;
  top: 100px;
  right: 20px;
  background: #2c3e50;
  padding: 20px;
  border-radius: 6px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  width: 200px;
  z-index: 1000;
}

.fixed-nav h3 {
  color: #fff;
  margin-bottom: 10px;
  font-size: 18px;
}

.fixed-nav ul {
  list-style: none;
  padding: 0;
}

.fixed-nav li {
  margin: 8px 0;
}

.fixed-nav a {
  color: #4da3ff;
  text-decoration: none;
  font-size: 14px;
}

.fixed-nav a:hover {
  color: #1f78d1;
  text-decoration: underline;
}

/* Navigation button styles */
.fixed-nav .nav-button {
  font-weight: bold;
  color: #fff;
  background: #4da3ff;
  padding: 5px 10px;
  border-radius: 3px;
  display: block;
  text-align: center;
  margin-top: 10px;
}

.fixed-nav .nav-button a {
  color: #fff;
  text-decoration: none;
}

.fixed-nav .nav-button:hover {
  background: #fff;
}

.fixed-nav .nav-button:hover a {
  color: #4da3ff;
}

/* Navigation button container */
.nav-buttons {
  margin-top: 10px;
}

/* Project number styles */
.project-number {
  text-align: center;
  font-size: 1.5em;
  font-weight: bold;
  margin: 10px 0;
}

.nav-buttons .nav-button {
  display: block;
  margin: 5px 0;
}