:root {
  /* Pythonized Colors */
  --color-bg-body: #f6f8fa;
  --color-bg-card: #fbfdff;
  --color-bg-header: #306998;
  --color-bg-footer: #2f3654;

  --color-primary: #3776ab;
  --color-primary-dark: #264769;

  /* Replace accent yellow with primary blue to keep consistent blue/white */
  --color-accent: #3776ab;       /* same as primary */
  --color-accent-dark: #264769;  /* same as primary dark */

  --color-text-main: #193252;
  --color-text-secondary: #46628a;
  --color-text-footer: #f5dcc0;

  /* Spacing & Radius */
  --radius: 16px;

  /* Shadows */
  --shadow-card: 0 2px 18px #26476912;
  --shadow-hover: 0 5px 25px #26476928;

  /* Typography */
  --font-family: 'Segoe UI', 'Poppins', Arial, sans-serif;
}

body {
  background: var(--color-bg-body);
  color: var(--color-text-main);
  font-family: var(--font-family);
  line-height: 1.7;
  margin: 0;
  padding: 0;
}

a {
  color: var(--color-primary);
  transition: color 0.17s;
  text-decoration: none;
}

a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

/* HEADER */
.header {
  background: linear-gradient(90deg, var(--color-bg-header) 63%, var(--color-accent) 100%);
  color: #fff;
  padding: 1rem 2rem;
  border-bottom: 2px solid #eaeaea;
  box-shadow: 0 2px 8px #0001;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
}

.logo h1 {
  display: flex;
  align-items: center;
  font-size: 2.1rem;
  font-weight: bold;
  color: var(--color-accent);
  letter-spacing: 2px;
  text-shadow: 0 2px 12px #0002;
  margin: 0;
}

/* Example: Place SVG Python logo before text in HTML */
.logo h1 svg {
  vertical-align: middle;
  margin-right: 12px;
}

.nav, .nav ul {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  list-style: none;
  margin: 0;
  background: none;
  padding: 0;
}

.nav a {
  color: #fff;
  font-weight: 500;
  border-bottom: 2px solid transparent;
  padding: var(--space-2, 0.5rem) 0;
  transition: border 0.17s, color 0.17s;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.nav a.active, .nav a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 11;
  padding: 0.5rem;
  min-height: 44px;
  min-width: 44px;
  justify-content: center;
  align-items: center;
}

.mobile-menu-btn span {
  width: 28px;
  height: 4px;
  background: #fff;
  border-radius: 2px;
  transition: all 0.25s;
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 4px);
}
.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* HERO SECTION */
.hero {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  padding: 3rem 1.1rem 2rem;
  /* Change hero gradient: blue to a lighter blue instead of yellow */
  background: linear-gradient(90deg, #306998 60%, #a0c4ff 110%);
  border-bottom: 1px solid #e6eef7;
  min-height: 350px;
}

.hero-content {
  flex: 1 1 340px;
  max-width: 540px;
}

.hero-title {
  font-size: 2.5rem;
  color: var(--color-primary-dark);
  font-weight: bold;
  margin-bottom: 0.45em;
  letter-spacing: 1.5px;
  line-height: 1.2;
}

.highlight {
  /* Use primary accent (blue) */
  color: var(--color-accent);
  font-weight: 700;
  letter-spacing: 2px;
}

.hero-subtitle {
  color: var(--color-text-secondary);
  font-size: 1.19rem;
  margin: 1em 0 2em;
  line-height: 1.6;
}

.cta-button {
  font-weight: 600;
  padding: 0.75em 2em;
  border-radius: var(--radius);
  background: var(--color-accent);
  color: var(--color-bg-header);
  border: none;
  font-size: 1.13rem;
  letter-spacing: 1px;
  box-shadow: var(--shadow-card);
  transition: background 0.14s, color 0.14s, box-shadow 0.19s;
  cursor: pointer;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.cta-button:hover {
  background: var(--color-accent-dark);
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-hover);
}

.hero-image {
  flex: 1 1 300px;
  margin-top: 2rem;
}

/* CODE SNIPPET */
.code-snippet {
  background: #232833;
  /* Replace yellow text with a softer blue-based color */
  color: #9cc4ff;
  padding: 1.1rem 1.3rem;
  font-family: 'Fira Mono', monospace;
  font-size: 1rem;
  border-radius: 1.2em;
  overflow-x: auto;
  box-shadow: 0 3px 18px #22486928;
  margin-top: 0.8em;
  border-left: 8px solid var(--color-primary);
  position: relative;
  line-height: 1.5;
}

.code-snippet::before {
  content: "";
  display: block;
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 7px;
  /* Gradient from primary blue to a lighter blue instead of yellow */
  background: linear-gradient(90deg, #3776ab 60%, #a0c4ff 100%);
  border-radius: 1.2em 1.2em 0 0;
}

/* FEATURES */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
  padding: 2.2rem 1.1rem;
  background: #fff;
}

.feature {
  background: var(--color-bg-card);
  padding: 1.2rem .9rem 1.2rem 1.2rem;
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  text-align: center;
  border: 1.7px solid #ecf2f7;
  color: var(--color-primary-dark);
  transition: box-shadow 0.22s, background 0.21s, transform 0.25s;
}

.feature:hover {
  background: #e6f0ff; /* a lighter blue highlight instead of yellow */
  box-shadow: var(--shadow-hover);
  transform: translateY(-5px) scale(1.015);
}

.feature-icon {
  font-size: 2.2rem;
  margin-bottom: .7rem;
  color: var(--color-accent);
  text-shadow: 1px 2px 8px #a0c4ff44;
}

.feature h3 {
  line-height: 1.3;
  margin-bottom: 0.5rem;
}

.feature p {
  line-height: 1.5;
}

/* PREVIEW SECTION */
.preview {
  padding: 2.3rem 1.1rem;
  background: #fcfcfa;
  text-align: center;
  border-top: 1.5px solid #e2eaf9;
}

.preview h2 {
  line-height: 1.3;
  margin-bottom: 2rem;
}

.topics-preview {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1.2rem;
  margin: 2rem 0;
}

.topic-card {
  background: #fbfdfa;
  padding: 1em;
  border-radius: var(--radius);
  box-shadow: 2px 3px 12px #27476c11;
  border: 1.5px solid #e3ebf5;
  color: var(--color-primary-dark);
  transition: background 0.24s, box-shadow 0.24s, transform 0.23s;
}

.topic-card:hover {
  background: #ddeaff; /* lighter blue hover */
  transform: translateY(-3px) scale(1.02);
  box-shadow: var(--shadow-hover);
}

.topic-card h3 {
  line-height: 1.3;
  margin-bottom: 0.6rem;
}

.topic-card p {
  line-height: 1.5;
}

.secondary-button {
  background: none;
  color: var(--color-primary-dark);
  border: 2px solid var(--color-primary);
  padding: .6rem 1.4rem;
  border-radius: 12px;
  font-weight: 500;
  transition: background 0.14s, color 0.15s;
  margin-top: .7em;
  cursor: pointer;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.secondary-button:hover {
  background: var(--color-primary);
  color: #f0f7ff;
}

/* FOOTER */
.footer {
  background: var(--color-bg-footer);
  color: var(--color-text-footer);
  padding: 2rem 2rem 1.2rem 2rem;
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 2rem;
}

.footer-logo h2 {
  color: var(--color-accent);
  margin-bottom: 0.5rem;
  font-weight: 600;
  letter-spacing: .7px;
}

.footer-logo p {
  line-height: 1.5;
}

.footer-links h3,
.footer-social h3 {
  color: var(--color-accent);
}

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

.footer-links li {
  margin: 0.2rem 0;
}

.footer-links a {
  color: var(--color-accent);
  transition: color .18s;
  padding: 0.25rem 0;
  display: inline-block;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.footer-links a:hover {
  color: #fff;
}

.social-icons {
  display: flex;
  gap: 1rem;
  margin-top: 0.5rem;
}

.social-icon {
  min-height: 44px;
  min-width: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.social-icon svg {
  stroke: var(--color-accent);
  transition: stroke 0.18s;
  width: 24px;
  height: 24px;
}

.social-icon:hover svg {
  stroke: #f0f7ff;
}

.footer-bottom {
  text-align: center;
  margin-top: 2rem;
  font-size: 0.95rem;
  border-top: 1px solid #252b35;
  padding-top: 1rem;
  color: #a0c4ff;
  line-height: 1.5;
}

/* ANIMATIONS & RESPONSIVE */
.topic-card,
.feature,
.content-section {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.48s cubic-bezier(.4,1.1,.5,1);
}

.topic-card.visible, 
.feature.visible, 
.content-section.visible {
  opacity: 1;
  transform: translateY(0);
}

body.no-scroll { 
  overflow: hidden; 
}

/* RESPONSIVE NAV & SECTIONS */
@media (max-width: 1024px) {
  .features, 
  .footer-content {
    flex-direction: column;
  }
  
  .hero {
    flex-direction: column;
    padding: 2.5rem 1rem;
  }
  
  .features {
    padding: 2rem 1rem;
    gap: 1.2rem;
  }
  
  .preview {
    padding: 2rem 1rem;
  }
}

@media (max-width: 768px) {
  .mobile-menu-btn { 
    display: flex; 
  }
  
  .header {
    padding: 0.75rem 1rem;
  }
  
  .logo h1 {
    font-size: 1.6rem;
    letter-spacing: 1px;
  }
  
  .nav {
    position: fixed;
    top: 0; 
    right: 0;
    height: 100vh;
    width: 80vw;
    max-width: 300px;
    background: var(--color-bg-header);
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    gap: 0;
    padding: 70px 0 0 0;
    transform: translateX(100%);
    transition: transform 0.33s, opacity 0.19s;
    z-index: 101;
    opacity: 0;
    visibility: hidden;
    box-shadow: -5px 0 15px rgba(0,0,0,0.1);
  }
  
  .nav.nav-open {
    transform: translateX(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav ul { 
    flex-direction: column; 
    gap: 0;
    width: 100%;
    padding: 0;
  }
  
  .nav a {
    font-size: 1.1rem;
    padding: 1rem 1.5rem;
    border-radius: 0;
    width: 100%;
    text-align: left;
    min-height: 44px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    border-left: none;
  }
  
  .nav a:hover,
  .nav a.active {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.2);
  }
  
  .hero {
    text-align: center;
    padding: 2rem 1rem;
    min-height: auto;
  }
  
  .hero-title {
    font-size: 2rem;
    margin-bottom: 1rem;
  }
  
  .hero-subtitle {
    font-size: 1.05rem;
    margin-bottom: 1.5rem;
  }
  
  .cta-button {
    width: 100%;
    max-width: 280px;
    padding: 0.75rem 1.5rem;
  }
  
  .hero-image {
    margin-top: 1.5rem;
    width: 100%;
  }
  
  .code-snippet {
    padding: 1rem;
    font-size: 0.9rem;
    margin-top: 1rem;
  }
  
  .features {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    padding: 1.5rem 1rem;
    gap: 1rem;
  }
  
  .feature {
    padding: 1rem;
  }
  
  .feature h3 {
    font-size: 1.1rem;
  }
  
  .preview {
    padding: 1.5rem 1rem;
  }
  
  .preview h2 {
    font-size: 1.6rem;
    margin-bottom: 1.5rem;
  }
  
  .topics-preview {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .topic-card {
    padding: 1rem;
  }
  
  .secondary-button {
    width: 100%;
    max-width: 280px;
  }
  
  .footer {
    padding: 1.5rem 1rem;
  }
  
  .footer-content {
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
  }
  
  .social-icons {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .header { 
    padding: 0.5rem 0.75rem;
  }
  
  .logo h1 {
    font-size: 1.4rem;
  }
  
  .nav {
    width: 90vw;
    padding: 60px 0 0 0;
  }
  
  .nav a {
    font-size: 1rem;
    padding: 0.75rem 1rem;
  }
  
  .hero {
    padding: 1.5rem 0.75rem;
  }
  
  .hero-title { 
    font-size: 1.6rem;
    line-height: 1.2;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .code-snippet {
    padding: 0.75rem;
    font-size: 0.85rem;
  }
  
  .features { 
    grid-template-columns: 1fr; 
    gap: 0.75rem;
    padding: 1.25rem 0.75rem;
  }
  
  .feature {
    padding: 0.75rem;
  }
  
  .feature-icon {
    font-size: 1.8rem;
  }
  
  .feature h3 {
    font-size: 1rem;
  }
  
  .preview {
    padding: 1.25rem 0.75rem;
  }
  
  .preview h2 {
    font-size: 1.4rem;
  }
  
  .topic-card {
    padding: 0.75rem;
  }
  
  .footer {
    padding: 1.25rem 0.75rem;
    font-size: 0.9rem;
  }
}

/* Touch-friendly improvements */
@media (max-width: 768px) {
  /* Disable hover effects on touch devices */
  .feature:hover,
  .topic-card:hover {
    transform: none;
    background: var(--color-bg-card);
  }
  
  /* Add active states for better touch feedback */
  .feature:active,
  .topic-card:active {
    transform: scale(0.98);
    transition: transform 0.1s;
  }
  
  .cta-button:active,
  .secondary-button:active {
    transform: scale(0.95);
    transition: transform 0.1s;
  }
}

/* Improved text readability on small screens */
@media (max-width: 480px) {
  body {
    line-height: 1.6;
  }
  
  .hero-title,
  .preview h2,
  .feature h3 {
    line-height: 1.3;
  }
  
  .hero-subtitle,
  .feature p,
  .topic-card p {
    line-height: 1.5;
  }
}