/* ===== Global Styles ===== */
:root {
  /* Theme Colors - Unified Brand Colors */
  --color-primary: #2563EB; /* Primary Blue */
  --color-secondary: #1E40AF; /* Secondary Deep Blue */
  --color-primary-hover: #1D4ED8;
  --color-link: #2563EB;
  --color-bg: #F9FAFB; /* Background Gray */
  --color-text: #1F2937; /* Text Primary */
  --color-text-body: #1F2937;
  --color-text-secondary: #4B5563; /* Text Secondary */
  --color-border: #E5E7EB; /* Border Gray */
  --color-border-input: #D1D5DB;
  --color-hover-bg: #EFF6FF;
  --color-hover-border: #2563EB;
  --color-white: #FFFFFF;
  --color-gray-light: #F3F4F6;
  --color-gray-medium: #6B7280;
  
  /* Typography - System Fonts for Performance */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  --font-size-base: 16px;
  --font-size-h1: 32px;
  --font-size-h2: 24px;
  --font-size-h3: 20px;
  --line-height-base: 1.6;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 12px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  
  /* Transitions */
  --transition: 0.2s ease;

  /* Layout */
  --container-padding-x: 20px;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  margin: 0;
  padding: 0;
}

/* ===== Typography ===== */
h1 {
  font-size: var(--font-size-h1);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 var(--spacing-lg) 0;
  color: var(--color-text);
}

h2 {
  font-size: var(--font-size-h2);
  font-weight: 600;
  line-height: 1.3;
  margin: 0 0 var(--spacing-md) 0;
  color: var(--color-text);
}

h3 {
  font-size: var(--font-size-h3);
  font-weight: 600;
  line-height: 1.4;
  margin: 0 0 var(--spacing-md) 0;
  color: var(--color-text);
}

p {
  margin: 0 0 var(--spacing-md) 0;
  color: var(--color-text);
}

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--transition);
}

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

/* ===== Layout ===== */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 var(--container-padding-x);
  width: 100%;
}

/* ===== Header ===== */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #ffffff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

header .container {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px var(--container-padding-x);
  width: 100%;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--spacing-lg);
}

.logo-link,
.site-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  flex-shrink: 0;
  padding: 0;
  margin-right: var(--spacing-md);
}

header img {
  height: 40px;
  width: auto;
  display: block;
  content: url('/assets/logo.svg');
}

/* Ads removed for AdSense review */
.header-ad-slot,
.ad-placeholder,
ins.adsbygoogle {
  display: none !important;
}

/* (ads removed) */

@media (max-width: 768px) {
  header .container {
    padding: 0 var(--spacing-md);
  }
  
  /* (ads removed) */
  
  .header-content {
    justify-content: flex-start; /* Logo left on mobile */
  }
}

/* ===== Main Navigation ===== */
.main-navigation {
  background: transparent;
  border-bottom: none;
  margin-top: 0;
  position: sticky;
  top: 0;
  z-index: 99;
}

.main-navigation .container {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 var(--container-padding-x);
  width: 100%;
  position: relative;
}

/* Navigation surface (same width as hero content box) */
.main-navigation .container::before {
  content: "";
  position: absolute;
  left: var(--container-padding-x);
  right: var(--container-padding-x);
  top: 0;
  bottom: 0;
  background: #ffffff;
  /* Waldev-like: flat bar, no card chrome */
  border: none;
  border-radius: 0;
  box-shadow: none;
  z-index: 0;
}

/* Divider only across the content box (same width as hero) */
.main-navigation .container::after {
  content: "";
  position: absolute;
  left: var(--container-padding-x);
  right: var(--container-padding-x);
  bottom: 0;
  height: 1px;
  background: #e5e7eb;
  z-index: 1;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--spacing-xs);
  margin: var(--spacing-xs) 0;
  transition: color var(--transition-base);
  position: relative;
  z-index: 2;
}

.nav-toggle:hover {
  color: var(--brand-primary);
}

.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 28px;
  align-items: center;
  justify-content: flex-start;
  position: relative;
  z-index: 2;
}

.nav-menu li {
  margin: 0;
}

.nav-menu a {
  display: block;
  padding: 18px 6px;
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 700;
  font-size: 17px;
  transition: all var(--transition-base);
  position: relative;
  border-bottom: 1px solid transparent;
  border-radius: 4px;
}

.nav-menu a:hover {
  color: var(--brand-primary);
  background: #f8fafb;
}

.nav-menu a.active {
  color: var(--brand-primary);
  border-bottom-color: var(--brand-primary);
  font-weight: 600;
}

/* Mobile Navigation */
@media (max-width: 768px) {
  .main-navigation .container {
    justify-content: space-between;
  }

  .nav-toggle {
    display: block;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    flex-direction: column;
    align-items: stretch;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
    border-top: 1px solid var(--border-light);
  }

  .nav-menu.active {
    max-height: 300px;
  }

  .nav-menu li {
    width: 100%;
    border-bottom: 1px solid var(--border-light);
  }

  .nav-menu li:last-child {
    border-bottom: none;
  }

  .nav-menu a {
    padding: 14px 20px;
    border-bottom: none;
    width: 100%;
  }

  .nav-menu a.active {
    background: #f8fafb;
    border-left: 3px solid var(--brand-primary);
  }
}

/* ===== Main Content ===== */
main {
  min-height: calc(100vh - 200px);
  padding: 0 0 var(--spacing-xl) 0;
}

/* Ensure article pages have enough top spacing to prevent header overlap */
main:has(.article-content) {
  padding-top: 0; /* Remove default padding, let article-content handle it */
}

/* Prevent header overlap on article pages - handled in components.css with padding-top */

/* ===== Hero Section ===== */
.hero-section {
  text-align: center;
  padding: 80px 20px; /* Increased vertical spacing */
  margin-top: 0;
  margin-bottom: var(--spacing-2xl);
  background: var(--color-white); /* White background, no gradient */
}

.hero-section h1 {
  font-size: 48px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
}

.hero-description {
  font-size: 20px; /* Slightly larger */
  color: #555; /* #555 as specified */
  margin-bottom: 32px;
  font-weight: 400;
}

.hero-tagline {
  font-size: 16px;
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: 0;
}

.hero-cta {
  margin-top: var(--spacing-xl);
}

.hero-cta-btn {
  font-size: 1.1rem;
  padding: var(--spacing-md) var(--spacing-xl);
  min-width: 200px;
}

@media (max-width: 768px) {
  .hero-cta-btn {
    width: 100%;
    max-width: 280px;
  }
}

/* ===== Footer ===== */
footer {
  background-color: #F3F4F6; /* Light gray background */
  border-top: none; /* Remove border */
  padding: 30px 0;
  margin-top: 40px; /* 40px space above footer */
  font-size: 14px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
  text-align: center; /* Center aligned */
}

.footer-section h3 {
  font-size: var(--font-size-h3);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section a {
  color: #6B7280; /* Footer text color */
  font-size: 14px;
  text-decoration: none;
}

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

/* Add separator between links */
.footer-section ul li:not(:last-child)::after {
  content: ' · ';
  color: #6B7280;
  margin-left: 4px;
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  color: #6B7280; /* Footer text color */
  font-size: 14px;
}

/* ===== Utility Classes ===== */
.text-center {
  text-align: center;
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

.mb-xl {
  margin-bottom: var(--spacing-xl);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root {
    --font-size-h1: 28px;
    --font-size-h2: 22px;
    --spacing-lg: 20px;
    --spacing-xl: 24px;
    --container-padding-x: var(--spacing-md);
  }
  
  .container {
    padding: 0 var(--container-padding-x);
  }
  
  header {
    padding: var(--spacing-xs) 0;
  }
  
  header img {
    height: 36px;
  }
  
  main {
    padding: var(--spacing-lg) 0;
  }
  
  .hero-section {
    padding: var(--spacing-xl) var(--spacing-md);
  }
  
  .hero-section h1 {
    font-size: 32px; /* 移动端保持较大字号，与桌面端比例协调 */
  }
  
  .hero-description {
    font-size: 16px;
  }
  
  .hero-tagline {
    font-size: 14px;
  }
}


  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
}

.hero-description {
  font-size: 20px; /* Slightly larger */
  color: #555; /* #555 as specified */
  margin-bottom: 32px;
  font-weight: 400;
}

.hero-tagline {
  font-size: 16px;
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: 0;
}

.hero-cta {
  margin-top: var(--spacing-xl);
}

.hero-cta-btn {
  font-size: 1.1rem;
  padding: var(--spacing-md) var(--spacing-xl);
  min-width: 200px;
}

@media (max-width: 768px) {
  .hero-cta-btn {
    width: 100%;
    max-width: 280px;
  }
}

/* ===== Footer ===== */
footer {
  background-color: #F3F4F6; /* Light gray background */
  border-top: none; /* Remove border */
  padding: 30px 0;
  margin-top: 40px; /* 40px space above footer */
  font-size: 14px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
  text-align: center; /* Center aligned */
}

.footer-section h3 {
  font-size: var(--font-size-h3);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section a {
  color: #6B7280; /* Footer text color */
  font-size: 14px;
  text-decoration: none;
}

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

/* Add separator between links */
.footer-section ul li:not(:last-child)::after {
  content: ' · ';
  color: #6B7280;
  margin-left: 4px;
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  color: #6B7280; /* Footer text color */
  font-size: 14px;
}

/* ===== Utility Classes ===== */
.text-center {
  text-align: center;
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

.mb-xl {
  margin-bottom: var(--spacing-xl);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root {
    --font-size-h1: 28px;
    --font-size-h2: 22px;
    --spacing-lg: 20px;
    --spacing-xl: 24px;
    --container-padding-x: var(--spacing-md);
  }
  
  .container {
    padding: 0 var(--container-padding-x);
  }
  
  header {
    padding: var(--spacing-xs) 0;
  }
  
  header img {
    height: 36px;
  }
  
  main {
    padding: var(--spacing-lg) 0;
  }
  
  .hero-section {
    padding: var(--spacing-xl) var(--spacing-md);
  }
  
  .hero-section h1 {
    font-size: 32px; /* 移动端保持较大字号，与桌面端比例协调 */
  }
  
  .hero-description {
    font-size: 16px;
  }
  
  .hero-tagline {
    font-size: 14px;
  }
}