:root {
  --primary: #0d9488; /* Tech Teal */
  --primary-hover: #0f766e;
  --accent: #FCD535; /* Brand Yellow */
  --accent-hover: #eab308;
  --bg-color: #f8fafc;
  --surface: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.8);
  --text-main: #0f172a;
  --text-muted: #475569;
  --border: #e2e8f0;
  --radius-lg: 16px;
  --radius-md: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.05), 0 4px 6px -2px rgba(0,0,0,0.02);
  --transition: all 0.3s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Nav */
header {
  position: sticky;
  top: 0;
  background: var(--surface-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}
.nav-wrapper .btn-primary {
  padding: 5px 8px;
}
.nav-wrapper .btn-primary::before {
    content: "";
  display: inline-block;
  width: 24px;
  height: 24px;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-image: url("/assets/icon/binance.svg");
}

.nav-wrapper .btn-primary::after {
    content: "";
  display: inline-block;
  width: 24px;
  height: 24px;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='currentColor' d='M13.47 8.53a.75.75 0 0 1 1.06-1.06l4 4a.75.75 0 0 1 0 1.06l-4 4a.75.75 0 1 1-1.06-1.06l2.72-2.72H6.5a.75.75 0 0 1 0-1.5h9.69z'/%3E%3C/svg%3E");
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 8px;
}
.logo::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 24px;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-image: url("/logo.svg");
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--primary);
}

/* Language Selector */
.lang-selector {
  position: relative;
  font-size: 0.9rem;
}

.lang-current {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  padding: 3px 8px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: var(--transition);
  font-weight: 500;
  font-size: 0.75rem;
}

.lang-current:hover {
  border-color: var(--primary);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  min-width: 120px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
}

.lang-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-dropdown a {
  padding: 5px 8px;
  color: var(--text-muted);
  transition: var(--transition);
  font-size: 0.7rem;
}

.lang-dropdown a:hover {
  background: var(--bg-color);
  color: var(--primary);
}

.lang-dropdown a.active {
  color: var(--primary);
  font-weight: 600;
  background: var(--bg-color);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background-color: var(--accent);
  color: #000000;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--surface);
  color: var(--primary);
  border: 1px solid var(--primary);
}

.btn-secondary:hover {
  background-color: var(--bg-color);
}

/* Hero Section */
.hero-wrapper {
  padding-top: 40px;
}

.hero {
  background: linear-gradient(135deg, #0b0e11 0%, #1e2329 100%);
  border-radius: 24px;
  padding: 80px 64px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 64px;
  align-items: center;
  box-shadow: 0 24px 48px rgba(11, 14, 17, 0.15);
  overflow: hidden;
  position: relative;
}

.hero-content h1 {
  font-size: 3.5rem;
  line-height: 1.2;
  margin-bottom: 24px;
  color: #ffffff;
  letter-spacing: -0.02em;
}

.brand-highlight {
  color: var(--accent);
  position: relative;
  display: inline-block;
}

.brand-highlight::after {
  content: '';
  position: absolute;
  bottom: 8px;
  left: 0;
  width: 100%;
  height: 12px;
  background: rgba(252, 213, 53, 0.2);
  z-index: -1;
  transform: skewX(-15deg);
}

.hero-content p {
  font-size: 1.125rem;
  color: #848e9c;
  margin-bottom: 40px;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn-large {
  padding: 16px 32px;
  font-size: 1.125rem;
  border-radius: 12px;
}

.hero-btn-secondary {
  background-color: transparent;
  border-color: rgba(255, 255, 255, 0.3);
  color: #ffffff;
}

.hero-btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: #ffffff;
  color: #ffffff;
}

.action-hint {
  margin-top: 16px;
  display: flex;
  gap: 24px;
  font-size: 0.875rem;
  color: #848e9c;
}

.action-hint span {
  display: flex;
  align-items: center;
}

/* Hero Visual - Pure CSS Illustration */
.hero-visual {
  position: relative;
  height: 100%;
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.css-illustration {
  position: relative;
  width: 100%;
  height: 400px;
}

@keyframes spin { 100% { transform: translate(-50%, -50%) rotate(360deg); } }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-15px); } }

.css-graphic-circle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 320px;
  height: 320px;
  border-radius: 50%;
  border: 1px dashed rgba(252, 213, 53, 0.3);
  animation: spin 40s linear infinite;
}

.css-coin {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120px;
  height: 120px;
  background: linear-gradient(135deg, #FCD535 0%, #f0b90b 100%);
  border-radius: 50%;
  box-shadow: 0 12px 32px rgba(240, 185, 11, 0.3), inset 0 2px 0 rgba(255,255,255,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  animation: float 4s ease-in-out infinite;
}

.css-coin::before {
  content: '';
  position: absolute;
  width: 90px;
  height: 90px;
  border: 2px solid rgba(11, 14, 17, 0.1);
  border-radius: 50%;
}

.css-coin-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  z-index: 2;
}

.css-coin-diamond {
  width: 18px;
  height: 18px;
  background: #0b0e11;
  transform: rotate(45deg);
  border-radius: 2px;
}

.css-coin-row {
  display: flex;
  gap: 4px;
}

.css-float-card {
  position: absolute;
  background: rgba(30, 35, 41, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,0.05);
  padding: 16px 24px;
  border-radius: 16px;
  box-shadow: 0 16px 32px rgba(0,0,0,0.3);
  z-index: 5;
}

.css-float-card.c1 { top: 10%; left: 0; animation: float 5s ease-in-out infinite 1s; }
.css-float-card.c2 { bottom: 15%; right: 0; animation: float 6s ease-in-out infinite 2s; }
.css-float-card.c3 { top: 20%; right: 10%; animation: float 4.5s ease-in-out infinite 0.5s; padding: 12px 20px; }

.c-label { font-size: 0.75rem; color: #848e9c; margin-bottom: 4px; text-transform: uppercase; letter-spacing: 0.05em; }
.c-value { font-size: 1.5rem; font-weight: 700; color: #ffffff; }

.css-chart-container {
  position: absolute;
  bottom: 10%;
  left: 15%;
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: 80px;
  opacity: 0.8;
  z-index: 1;
}

.css-bar { width: 14px; border-radius: 4px 4px 0 0; }
.css-bar.up { background: #0ecb81; }
.css-bar.down { background: #f6465d; }

/* Article Grid (Content Matrix) */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 32px;
}

.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.article-content {
  padding: 32px 24px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

.article-tag {
  font-size: 0.75rem;
  color: var(--primary);
  text-transform: uppercase;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
}

.article-title {
  font-size: 1.25rem;
  margin-bottom: 16px;
  line-height: 1.5;
}

.article-title a {
  color: var(--text);
  text-decoration: none;
}

.article-title a::before {
  content: '';
  position: absolute;
  inset: 0;
}

.article-excerpt {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 24px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

/* Article Page Layout */
.article-layout {
  max-width: 800px;
  margin: 0 auto;
  padding: 120px 24px 80px;
}
.breadcrumb {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}
.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}
.article-header {
  margin-bottom: 48px;
  position: sticky;
  top: 72px;
  background: var(--bg-color);
  padding: 24px 0 0 0;
  z-index: 90;
  box-shadow: 0 10px 10px -10px var(--bg-color);
  position: unset;
}
.article-header h1 {
  font-size: 2.5rem;
  line-height: 1.3;
  margin-bottom: 16px;
}
.article-meta-info {
  display: flex;
  gap: 24px;
  color: var(--text-muted);
  font-size: 0.95rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 24px;
  flex-wrap: wrap;
}
.article-body h2 {
  font-size: 1.75rem;
  margin: 48px 0 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.article-body h3 {
  font-size: 1.25rem;
  margin: 32px 0 16px;
}
.article-body p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 24px;
  color: var(--text);
}
.article-body ul, .article-body ol {
  margin-bottom: 24px;
  padding-left: 24px;
}
.article-body li {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 12px;
}
.highlight-box {
  background: rgba(24, 203, 129, 0.05);
  border-left: 4px solid var(--primary);
  padding: 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 32px 0;
}
.cta-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
  margin: 48px 0;
}
.cta-box h3 {
  margin-top: 0;
  margin-bottom: 16px;
}

.cta-box a::before {
    content: "";
  display: inline-block;
  width: 24px;
  height: 24px;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-image: url("/assets/icon/binance.svg");
}

.cta-box a::after {
    content: "";
  display: inline-block;
  width: 24px;
  height: 24px;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='currentColor' d='M13.47 8.53a.75.75 0 0 1 1.06-1.06l4 4a.75.75 0 0 1 0 1.06l-4 4a.75.75 0 1 1-1.06-1.06l2.72-2.72H6.5a.75.75 0 0 1 0-1.5h9.69z'/%3E%3C/svg%3E");
}

/* Sections Common */
section {
  padding: 80px 0 !important;
}

.section-alt {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.section-header h2 {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.125rem;
}

/* Guide Steps Section */
.guide-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  position: relative;
}

.guide-steps::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 50px;
  right: 50px;
  height: 2px;
  background: var(--border);
  z-index: 0;
}

.step-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  position: relative;
  z-index: 1;
  transition: var(--transition);
}

.step-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.step-number {
  width: 48px;
  height: 48px;
  background: var(--bg-color);
  border: 2px solid var(--primary);
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 24px;
  background: var(--surface);
}

.step-card h3 {
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.step-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Grid Layouts for Sections */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.feature-box {
  background: var(--surface);
  padding: 40px 32px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  text-align: center;
  transition: var(--transition);
}

.feature-box:hover {
  box-shadow: var(--shadow-md);
}

.feature-box .icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 24px;
  background: var(--bg-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
}

.feature-box h3 {
  margin-bottom: 16px;
  font-size: 1.25rem;
}

.feature-box p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Security Section */
.security-section {
  padding: 0;
}

.security-box {
  border: none;
  box-shadow: none;
}

.security-box:hover {
  box-shadow: none;
  transform: translateY(-5px);
}

/* Review Section */
.review-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.review-item {
  display: flex;
  gap: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

.review-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.review-score {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  min-width: 80px;
}

.review-text h4 {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.review-text p {
  color: var(--text-muted);
}

/* FAQ Section */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  padding: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.1rem;
  transition: var(--transition);
}

.faq-question:hover {
  color: var(--primary);
}

.faq-icon {
  transition: transform 0.3s ease;
  color: var(--text-muted);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
  color: var(--primary);
}

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
  color: var(--text-muted);
}

.faq-item.active .faq-answer {
  padding: 0 24px 24px;
  max-height: 500px;
}

/* Footer */
footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
  margin-top: 64px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 64px;
  margin-bottom: 48px;
}

.footer-brand p {
  color: var(--text-muted);
  margin-top: 16px;
  max-width: 400px;
}

.footer-links h4 {
  font-size: 1.1rem;
  margin-bottom: 24px;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  color: var(--text-muted);
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

.disclaimer {
  margin-top: 16px;
  font-size: 0.8rem;
  opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 992px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 48px 32px;
  }
  
  .hero-content p {
    margin: 0 auto 40px;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .action-hint {
    justify-content: center;
  }
  
  .guide-steps::before {
    display: none;
  }
  
  .guide-steps {
    grid-template-columns: 1fr;
  }
  
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* Mobile menu omitted for brevity, focusing on core requirements */
  }
  
  .hero-content h1 {
    font-size: 2.5rem;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
  }
  
  .grid-3 {
    grid-template-columns: 1fr;
  }
  
  .review-item {
    flex-direction: column;
    gap: 8px;
  }
}