/* Global Styles & Variables */
:root {
  --bg-color: #EED045; /* 秋葵黄 */
  --text-color: #1a1a1a;
  --text-light: #4b5563;
  --accent-color: #ff6b6b; /* 撞色渐变起点 */
  --accent-gradient: linear-gradient(135deg, #ff6b6b 0%, #845ec2 100%);
  --nav-bg: rgba(238, 208, 69, 0.85);
  
  --card-bg: rgba(255, 255, 255, 0.9);
  --card-shadow: 0 10px 30px rgba(0,0,0,0.1);
  --hover-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

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

body {
  font-family: 'KaiTi', '楷体', STKaiti, serif; /* 强制正楷体 */
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  overflow-x: hidden;
  font-size: 18px;
}

a {
  text-decoration: none;
  color: inherit;
  transition: all 0.3s ease;
}

ul {
  list-style: none;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Nav */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255,255,255,0.3);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.logo {
  font-size: 28px;
  font-weight: 900;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 2px;
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-links a {
  font-weight: bold;
  font-size: 1.1rem;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 3px;
  bottom: -5px;
  left: 0;
  background: var(--accent-gradient);
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-btn {
  background: var(--accent-gradient);
  color: white !important;
  padding: 10px 25px;
  border-radius: 30px;
  font-weight: bold;
  box-shadow: 0 4px 15px rgba(255, 107, 107, 0.4);
}
.nav-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(255, 107, 107, 0.6);
}

/* Hero Section (Parallax) */
.hero {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding-top: 80px;
  background-image: radial-gradient(circle at 20% 50%, rgba(255,255,255,0.4) 0%, transparent 50%),
                    radial-gradient(circle at 80% 80%, rgba(255,107,107,0.2) 0%, transparent 50%);
  position: relative;
}

/* Parallax decorative elements */
.parallax-el {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  z-index: -1;
  opacity: 0.6;
}
.p-1 { width: 300px; height: 300px; background: #ff9a9e; top: 10%; left: -10%; animation: float 10s infinite ease-in-out; }
.p-2 { width: 400px; height: 400px; background: #a18cd1; bottom: -10%; right: -10%; animation: float 12s infinite reverse; }

@keyframes float {
  0% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-50px) rotate(10deg); }
  100% { transform: translateY(0) rotate(0deg); }
}

.hero-content {
  max-width: 800px;
  position: relative;
  z-index: 10;
}

.hero-title {
  font-size: 4.5rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 20px;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

.hero-title span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.5rem;
  color: var(--text-light);
  margin-bottom: 40px;
}

.btn-primary {
  display: inline-block;
  background: var(--text-color);
  color: #EED045;
  padding: 15px 40px;
  font-size: 1.3rem;
  border-radius: 50px;
  font-weight: bold;
  box-shadow: 0 10px 20px rgba(0,0,0,0.15);
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.btn-primary:hover {
  transform: scale(1.05) translateY(-5px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.25);
  background: var(--accent-gradient);
  color: white;
}

/* Sections */
.section {
  padding: 100px 0;
  position: relative;
}

.section-title {
  text-align: center;
  font-size: 3rem;
  font-weight: bold;
  margin-bottom: 60px;
  position: relative;
}
.section-title::after {
  content: '';
  display: block;
  width: 100px;
  height: 4px;
  background: var(--accent-gradient);
  margin: 15px auto 0;
  border-radius: 2px;
}

/* Asymmetric Layout for Advantages */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  align-items: center;
}

.adv-card {
  background: var(--card-bg);
  padding: 40px;
  border-radius: 30px;
  box-shadow: var(--card-shadow);
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
}
.adv-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; width: 100%; height: 5px;
  background: var(--accent-gradient);
}
.adv-card:hover {
  transform: translateY(-10px) rotate(-1deg);
  box-shadow: var(--hover-shadow);
}
.adv-card h3 {
  font-size: 1.8rem;
  margin-bottom: 15px;
}
.adv-card p {
  color: var(--text-light);
}

.adv-card:nth-child(2) { transform: translateY(40px); }
.adv-card:nth-child(2):hover { transform: translateY(30px) rotate(1deg); }

/* Pricing Cards - Replicating Image 1 details with Asymmetric style */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-top: 50px;
  align-items: center;
}

.pricing-card {
  background: #111827; /* Dark background from image 1 */
  color: white;
  border-radius: 20px;
  padding: 40px 30px;
  text-align: center;
  box-shadow: var(--card-shadow);
  transition: all 0.4s ease;
  border: 1px solid rgba(255,255,255,0.1);
  position: relative;
}

.pricing-card:hover {
  transform: translateY(-15px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.3);
  border-color: rgba(255,255,255,0.3);
}

/* Center card highlight */
.pricing-card.popular {
  transform: scale(1.05);
  background: #1f2937;
  border: 2px solid #818cf8; /* Light blue border from image */
  overflow: hidden;
}
.pricing-card.popular:hover {
  transform: translateY(-15px) scale(1.08);
}
.ribbon {
  position: absolute;
  top: 20px;
  right: -35px;
  background: #818cf8; /* Light blue */
  color: white;
  padding: 5px 40px;
  transform: rotate(45deg);
  font-size: 0.9rem;
  font-weight: bold;
}

.plan-name {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 20px;
}

.plan-price {
  font-size: 3rem;
  font-weight: bold;
  margin-bottom: 30px;
  color: white;
}
.plan-price span {
  font-size: 1rem;
  color: #9ca3af;
}
.popular .plan-price {
  color: #60a5fa; /* Blue price for popular */
}

.plan-features {
  text-align: left;
  margin-bottom: 40px;
}
.plan-features li {
  margin-bottom: 15px;
  color: #d1d5db;
  display: flex;
  align-items: flex-start;
  font-size: 0.95rem;
}
.plan-features li::before {
  content: '✓';
  color: #60a5fa;
  margin-right: 10px;
  font-weight: bold;
}

.btn-buy {
  display: block;
  width: 100%;
  padding: 15px;
  border-radius: 10px;
  background: #374151;
  color: white;
  font-weight: bold;
  font-size: 1.1rem;
  transition: all 0.3s ease;
}
.btn-buy:hover {
  background: #4b5563;
}
.popular .btn-buy {
  background: #818cf8;
}
.popular .btn-buy:hover {
  background: #6366f1;
}


/* Articles & Tutorials Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 30px;
}
.article-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 30px;
  box-shadow: var(--card-shadow);
  transition: all 0.4s;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-top: 4px solid #EED045;
}
.article-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--hover-shadow);
  border-top-color: #ff6b6b;
}
.article-tag {
  display: inline-block;
  background: rgba(255, 107, 107, 0.1);
  color: #ff6b6b;
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: bold;
  margin-bottom: 15px;
}
.article-title {
  font-size: 1.4rem;
  margin-bottom: 15px;
  line-height: 1.4;
}
.article-title a:hover {
  color: var(--accent-color);
}
.article-meta {
  display: flex;
  justify-content: space-between;
  color: var(--text-light);
  font-size: 0.9rem;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid rgba(0,0,0,0.1);
}

/* Footer */
footer {
  background: #111827;
  color: white;
  padding: 60px 0 20px;
  text-align: center;
}
footer a {
  color: #EED045;
}
footer a:hover {
  color: white;
}

/* Responsive */
@media (max-width: 992px) {
  .advantages-grid, .pricing-grid {
    grid-template-columns: 1fr;
  }
  .adv-card:nth-child(2) { transform: none; }
  .nav-links { display: none; } /* Add mobile menu logic if needed */
}