/* ==========================================================================
   Line Art Blueprint Schematic (线描结构图解) Theme - Telegram Standard CSS
   ========================================================================== */

:root {
  --bp-bg-dark: #07111e;
  --bp-bg-main: #0B192C;
  --bp-bg-card: #132A42;
  --bp-bg-panel: #1A3650;
  
  --bp-cyan: #00f0ff;
  --bp-cyan-glow: rgba(0, 240, 255, 0.25);
  --bp-cyan-border: rgba(0, 240, 255, 0.4);
  --bp-white: #e6f6ff;
  --bp-muted: #8ab4f8;
  --bp-accent-yellow: #ffd700;
  
  --grid-line: rgba(0, 240, 255, 0.05);
  --font-tech: 'Courier New', Consolas, Monaco, monospace;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bp-bg-main);
  color: var(--bp-white);
  line-height: 1.6;
  background-image: 
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 24px 24px;
}

a {
  color: var(--bp-cyan);
  text-decoration: none;
  transition: all 0.25s ease;
}

a:hover {
  color: #ffffff;
  text-shadow: 0 0 8px var(--bp-cyan);
}

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

/* ==========================================================================
   Header & Navigation (Line Art Blueprint Style)
   ========================================================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(7, 17, 30, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--bp-cyan-border);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0.5px;
}

.logo-icon {
  width: 40px;
  height: 40px;
  border: 1px solid var(--bp-cyan);
  background: rgba(0, 240, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--bp-cyan);
  font-size: 20px;
  border-radius: 4px;
  box-shadow: 0 0 10px var(--bp-cyan-glow);
}

.nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  color: var(--bp-white);
  font-size: 15px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 4px;
  position: relative;
}

.nav-link.active,
.nav-link:hover {
  color: var(--bp-cyan);
  background: rgba(0, 240, 255, 0.08);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 12px;
  right: 12px;
  height: 2px;
  background: var(--bp-cyan);
  box-shadow: 0 0 8px var(--bp-cyan);
}

/* ==========================================================================
   Buttons (Schematic Precise Border Style)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
  letter-spacing: 0.5px;
}

.btn-primary {
  background: var(--bp-cyan);
  color: var(--bp-bg-dark);
  border: 1px solid var(--bp-cyan);
  box-shadow: 0 0 12px var(--bp-cyan-glow);
  font-weight: 700;
}

.btn-primary:hover {
  background: #ffffff;
  color: var(--bp-bg-dark);
  border-color: #ffffff;
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.6);
}

.btn-outline {
  background: transparent;
  color: var(--bp-cyan);
  border: 1px dashed var(--bp-cyan);
}

.btn-outline:hover {
  background: rgba(0, 240, 255, 0.15);
  border-style: solid;
  color: #ffffff;
}

/* ==========================================================================
   Hero Banner Section
   ========================================================================== */
.hero {
  padding: 60px 0;
  text-align: center;
  position: relative;
}

.bp-tag {
  display: inline-block;
  font-family: var(--font-tech);
  font-size: 12px;
  color: var(--bp-cyan);
  background: rgba(0, 240, 255, 0.08);
  border: 1px solid var(--bp-cyan-border);
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 20px;
  letter-spacing: 1px;
}

.hero-title {
  font-size: 38px;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
  color: #ffffff;
}

.hero-title span {
  color: var(--bp-cyan);
  border-bottom: 2px dashed var(--bp-cyan);
}

.hero-subtitle {
  font-size: 17px;
  color: var(--bp-muted);
  max-width: 780px;
  margin: 0 auto 32px auto;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-bottom: 48px;
}

.gothic-showcase,
.bp-showcase {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 20px;
}

.bp-card {
  background: var(--bp-bg-card);
  border: 1px solid var(--bp-cyan-border);
  border-radius: 6px;
  padding: 12px;
  position: relative;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.bp-card::before {
  content: 'FIG. SCHEMATIC';
  position: absolute;
  top: -10px;
  left: 16px;
  font-family: var(--font-tech);
  font-size: 10px;
  color: var(--bp-cyan);
  background: var(--bp-bg-dark);
  padding: 0 6px;
  border: 1px solid var(--bp-cyan-border);
}

.bp-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px var(--bp-cyan-glow);
  border-color: var(--bp-cyan);
}

.bp-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 4px;
  border: 1px solid rgba(0, 240, 255, 0.2);
}

.bp-card-label {
  margin-top: 10px;
  font-size: 14px;
  font-weight: 600;
  color: var(--bp-white);
  font-family: var(--font-tech);
}

/* ==========================================================================
   Section Components
   ========================================================================== */
.section {
  padding: 60px 0;
  border-top: 1px solid rgba(0, 240, 255, 0.15);
}

.section-panel {
  background: var(--bp-bg-panel);
}

.section-title {
  text-align: center;
  margin-bottom: 48px;
}

.section-title h2 {
  font-size: 30px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
}

.section-title p {
  color: var(--bp-muted);
  font-size: 16px;
}

/* 3x3 Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bp-bg-card);
  border: 1px solid var(--bp-cyan-border);
  padding: 28px 24px;
  border-radius: 6px;
  position: relative;
  transition: all 0.3s ease;
}

.feature-card:hover {
  border-color: var(--bp-cyan);
  box-shadow: 0 0 16px var(--bp-cyan-glow);
  background: #173552;
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 4px;
  border: 1px solid var(--bp-cyan);
  background: rgba(0, 240, 255, 0.1);
  color: var(--bp-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: bold;
  font-family: var(--font-tech);
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #ffffff;
}

.feature-card p {
  font-size: 14px;
  color: var(--bp-muted);
  line-height: 1.6;
}

/* Blog / Tutorial Grid */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.blog-card {
  background: var(--bp-bg-card);
  border: 1px solid var(--bp-cyan-border);
  padding: 24px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.blog-card:hover {
  border-color: var(--bp-cyan);
  box-shadow: 0 4px 16px var(--bp-cyan-glow);
}

.blog-date {
  font-family: var(--font-tech);
  font-size: 12px;
  color: var(--bp-cyan);
  margin-bottom: 8px;
}

.blog-card h3 {
  font-size: 17px;
  color: #ffffff;
  margin-bottom: 12px;
  line-height: 1.4;
}

.blog-card p {
  font-size: 14px;
  color: var(--bp-muted);
  margin-bottom: 16px;
}

.blog-link {
  font-weight: 600;
  font-size: 14px;
}

.more-wrapper {
  text-align: center;
  margin-top: 36px;
}

/* FAQ Section */
.faq-container {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.faq-item {
  background: var(--bp-bg-card);
  border: 1px solid var(--bp-cyan-border);
  border-radius: 6px;
  padding: 22px;
}

.faq-question {
  font-size: 17px;
  font-weight: 700;
  color: var(--bp-cyan);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.faq-question::before {
  content: 'Q:';
  font-family: var(--font-tech);
  background: rgba(0, 240, 255, 0.15);
  padding: 2px 8px;
  border-radius: 3px;
}

.faq-answer {
  font-size: 14px;
  color: var(--bp-white);
  line-height: 1.7;
  padding-left: 36px;
}

/* Download Grid */
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.download-card {
  background: var(--bp-bg-card);
  border: 1px solid var(--bp-cyan-border);
  padding: 32px 24px;
  border-radius: 6px;
  text-align: center;
}

.download-card-icon {
  font-size: 36px;
  margin-bottom: 16px;
}

.download-card h3 {
  font-size: 20px;
  color: #ffffff;
  margin-bottom: 12px;
}

.download-card p {
  font-size: 14px;
  color: var(--bp-muted);
  margin-bottom: 24px;
  line-height: 1.6;
}

.download-web-banner {
  margin-top: 36px;
  background: var(--bp-bg-panel);
  border: 1px solid var(--bp-cyan);
  padding: 32px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 0 16px var(--bp-cyan-glow);
}

.download-web-banner h3 {
  font-size: 20px;
  color: #ffffff;
  margin-bottom: 8px;
}

.download-web-banner p {
  color: var(--bp-muted);
  font-size: 14px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  background-color: var(--bp-bg-dark);
  border-top: 1px solid var(--bp-cyan-border);
  padding: 60px 0 30px 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}

.footer-col h4 {
  font-size: 16px;
  font-weight: 700;
  color: var(--bp-cyan);
  margin-bottom: 18px;
  font-family: var(--font-tech);
}

.footer-col p {
  font-size: 14px;
  color: var(--bp-muted);
  line-height: 1.7;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--bp-muted);
  font-size: 14px;
}

.footer-col a:hover {
  color: var(--bp-cyan);
}

.footer-copyright {
  border-top: 1px solid rgba(0, 240, 255, 0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--bp-muted);
  font-family: var(--font-tech);
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .features-grid,
  .download-grid,
  .gothic-showcase,
  .bp-showcase {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    height: auto;
    padding: 12px 0;
    gap: 12px;
  }
  
  .nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
  }
  
  .hero-title {
    font-size: 28px;
  }
  
  .features-grid,
  .blog-grid,
  .download-grid,
  .gothic-showcase,
  .bp-showcase {
    grid-template-columns: 1fr;
  }
  
  .download-web-banner {
    flex-direction: column;
    text-align: center;
    gap: 20px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
}