:root {
  --primary-color: #007aff;
  --secondary-color: #5856d6;
  --accent-color: #ff9500;
  --text-primary: #1c1c1e;
  --text-secondary: #636366;
  --bg-primary: #ffffff;
  --bg-secondary: #f2f2f7;
  --bg-tertiary: #ffffff;
  --border-color: #e5e5ea;
  --shadow-light: rgba(0, 0, 0, 0.05);
  --shadow-medium: rgba(0, 0, 0, 0.1);
  --gradient-primary: linear-gradient(135deg, #007aff 0%, #5856d6 100%);
  --gradient-secondary: linear-gradient(135deg, #ff9500 0%, #ff6b6b 100%);
}

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

body {
  font-family:
    -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto,
    sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: all 0.3s ease;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 0;
  height: 70px;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-links a {
  font-size: 20px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

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

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: width 0.3s ease;
}

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

.back-button {
  background: var(--gradient-primary);
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  box-shadow: 0 4px 16px var(--shadow-light);
  display: flex;
  align-items: center;
  gap: 8px;
}

.back-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--shadow-medium);
}

/* Main Content */
main {
  padding: 120px 0 80px;
  min-height: 100vh;
}

.page-header {
  text-align: center;
  margin-bottom: 60px;
  padding: 40px 0;
  background: linear-gradient(135deg, #f8f9ff 0%, #ffffff 100%);
  border-radius: 24px;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="%23007AFF" opacity="0.02"/><circle cx="75" cy="75" r="1" fill="%235856D6" opacity="0.02"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  pointer-events: none;
}

.page-header h1 {
  font-size: 3rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  letter-spacing: -1px;
  position: relative;
  z-index: 1;
}

.page-header p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
}

.content {
  background: white;
  border-radius: 24px;
  padding: 60px;
  box-shadow: 0 8px 32px var(--shadow-light);
  border: 1px solid var(--border-color);
  margin-bottom: 40px;
}

.content h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 32px;
  padding-bottom: 16px;
  border-bottom: 3px solid var(--primary-color);
  position: relative;
}

.content h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 40px 0 20px 0;
  position: relative;
  padding-left: 20px;
}

.content h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 20px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.content p {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.content ol {
  margin: 24px 0;
  padding-left: 24px;
}

.content ol li {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-primary);
  margin-bottom: 16px;
  counter-increment: item;
}

.content ol li::marker {
  color: var(--primary-color);
  font-weight: 600;
}

.section {
  margin: 60px 0;
  padding: 40px;
  background: linear-gradient(
    135deg,
    rgba(0, 122, 255, 0.02) 0%,
    rgba(88, 86, 214, 0.02) 100%
  );
  border-radius: 16px;
  border-left: 4px solid var(--primary-color);
}

.highlight-box {
  background: linear-gradient(
    135deg,
    rgba(255, 149, 0, 0.1) 0%,
    rgba(255, 107, 107, 0.1) 100%
  );
  border: 1px solid rgba(255, 149, 0, 0.3);
  border-radius: 16px;
  padding: 24px;
  margin: 32px 0;
  position: relative;
}

.highlight-box::before {
  content: "ℹ️";
  position: absolute;
  top: -12px;
  left: 24px;
  background: white;
  padding: 0 8px;
  font-size: 1.2rem;
}

.contact-info {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 32px;
  text-align: center;
  margin: 40px 0;
}

.contact-info h3 {
  margin-bottom: 16px;
  padding-left: 0;
}

.contact-info h3::before {
  display: none;
}

.contact-info a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.3s ease;
}

.contact-info a:hover {
  color: var(--secondary-color);
}

/* Footer */
footer {
  background: var(--text-primary);
  color: white;
  padding: 40px 0 20px;
  margin-top: 80px;
}

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

.footer-links {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .container {
    padding: 0 16px;
  }

  .content {
    padding: 32px 24px;
    border-radius: 16px;
  }

  .page-header h1 {
    font-size: 2.2rem;
  }

  .content h2 {
    font-size: 1.6rem;
  }

  .content h3 {
    font-size: 1.3rem;
  }

  .section {
    padding: 24px;
    margin: 40px 0;
  }

  .footer-links {
    flex-direction: column;
    gap: 16px;
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Selection styling */
::selection {
  background: rgba(0, 122, 255, 0.2);
  color: var(--text-primary);
}

/* Focus styles for accessibility */
*:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}