/* Global Styles for SIV Digital */
:root {
  /* Light Mode Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --text-primary: #1a1a1a;
  --text-secondary: #6c757d;
  --border-color: #e9ecef;
  --shadow: rgba(0, 0, 0, 0.1);
  
  /* Dark Mode Colors */
  --bg-primary-dark: #0a0a0a;
  --bg-secondary-dark: #1a1a1a;
  --bg-card-dark: rgba(255, 255, 255, 0.05);
  --text-primary-dark: #f0f0f0;
  --text-secondary-dark: #a8a8a8;
  --border-color-dark: rgba(255, 255, 255, 0.1);
  --shadow-dark: rgba(0, 0, 0, 0.5);
  
  /* Brand Colors */
  --siv-primary: #2d3748;
  --siv-accent: #4a5568;
  
  /* App Colors from Logos */
  --music-primary: #00f5ff;
  --music-secondary: #8a2be2;
  --music-gradient: linear-gradient(135deg, #00f5ff, #8a2be2);
  
  --diary-primary: #d2691e;
  --diary-secondary: #cd853f;
  --diary-gradient: linear-gradient(135deg, #d2691e, #cd853f);
  
  --data-primary: #1a237e;
  --data-secondary: #303f9f;
  --data-gradient: linear-gradient(135deg, #1a237e, #303f9f);
}

/* Dark mode theme */
[data-theme="dark"] {
  --bg-primary: var(--bg-primary-dark);
  --bg-secondary: var(--bg-secondary-dark);
  --bg-card: var(--bg-card-dark);
  --text-primary: var(--text-primary-dark);
  --text-secondary: var(--text-secondary-dark);
  --border-color: var(--border-color-dark);
  --shadow: var(--shadow-dark);
}

/* Light mode (default) */
[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --text-primary: #1a1a1a;
  --text-secondary: #6c757d;
  --border-color: #e9ecef;
  --shadow: rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Theme Toggle Button */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 50px;
  padding: 10px 20px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  box-shadow: 0 4px 15px var(--shadow);
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--shadow);
}

.theme-toggle .icon {
  font-size: 16px;
}

header {
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border-color);
  box-shadow: 0 2px 10px var(--shadow);
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--siv-primary);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.logo .highlight {
  background: linear-gradient(45deg, var(--music-primary), var(--data-primary), var(--diary-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

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

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(45deg, var(--music-primary), var(--data-primary));
  transition: width 0.3s ease;
}

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

.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 30% 70%, rgba(26, 35, 126, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 70% 30%, rgba(210, 105, 30, 0.1) 0%, transparent 50%),
              radial-gradient(circle at 50% 50%, rgba(0, 245, 255, 0.05) 0%, transparent 70%);
  opacity: 0.6;
}

.hero-content {
  max-width: 900px;
  padding: 3rem 2rem;
  z-index: 1;
}

.hero h1 {
  font-size: 4rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--siv-primary) 0%, var(--data-primary) 50%, var(--diary-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.hero .subtitle {
  font-size: 1.4rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: 2.5rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.cta-button {
  display: inline-block;
  padding: 1.2rem 3rem;
  background: linear-gradient(135deg, var(--siv-primary), var(--data-primary));
  color: white;
  text-decoration: none;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1.1rem;
  transition: all 0.3s ease;
  box-shadow: 0 8px 25px var(--shadow);
}

.cta-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 35px var(--shadow);
}

.app-grid {
  max-width: 1200px;
  margin: 5rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 2.5rem;
}

.app-card {
  background: var(--bg-card);
  border-radius: 24px;
  overflow: hidden;
  transition: all 0.4s ease;
  border: 1px solid var(--border-color);
  box-shadow: 0 8px 30px var(--shadow);
}

.app-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 20px 50px var(--shadow);
}

.app-icon {
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.app-icon img {
  width: 120px;
  height: 120px;
  object-fit: contain;
  border-radius: 16px;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.app-card h3 {
  padding: 2rem 2rem 1rem;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
}

.app-card p {
  padding: 0 2rem 2rem;
  color: var(--text-secondary);
  font-size: 1.1rem;
  line-height: 1.6;
}

.app-card .btn {
  display: block;
  margin: 0 2rem 2rem;
  padding: 1rem 2rem;
  text-align: center;
  text-decoration: none;
  border-radius: 12px;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
}

/* App-specific styling */
.app-card.music-theme {
  border-color: var(--music-primary);
}

.app-card.music-theme .app-icon {
  background: var(--music-gradient);
}

.app-card.music-theme .btn {
  background: var(--music-gradient);
  color: white;
}

.app-card.diary-theme {
  border-color: var(--diary-primary);
}

.app-card.diary-theme .app-icon {
  background: var(--diary-gradient);
}

.app-card.diary-theme .btn {
  background: var(--diary-gradient);
  color: white;
}

.app-card.data-theme {
  border-color: var(--data-primary);
}

.app-card.data-theme .app-icon {
  background: var(--data-gradient);
}

.app-card.data-theme .btn {
  background: var(--data-gradient);
  color: white;
}

/* Theme Modifiers */
.theme-music {
  --theme-primary: var(--music-primary);
  --theme-secondary: var(--music-secondary);
  --theme-gradient: var(--music-gradient);
}

.theme-diary {
  --theme-primary: var(--diary-primary);
  --theme-secondary: var(--diary-secondary);
  --theme-gradient: var(--diary-gradient);
}

.theme-data {
  --theme-primary: var(--data-primary);
  --theme-secondary: var(--data-secondary);
  --theme-gradient: var(--data-gradient);
}

/* Product Page Common */
.product-header {
  padding: 5rem 2rem 3rem;
  text-align: center;
  background: var(--bg-secondary);
  position: relative;
}

.product-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  opacity: 0.1;
}

.theme-music .product-header::before {
  background: var(--music-gradient);
}

.theme-diary .product-header::before {
  background: var(--diary-gradient);
}

.theme-data .product-header::before {
  background: var(--data-gradient);
}

.product-icon {
  width: 200px;
  height: 200px;
  margin: 0 auto 2.5rem;
  border-radius: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 20px 60px var(--shadow);
  position: relative;
  z-index: 1;
}

.product-icon img {
  width: 160px;
  height: 160px;
  object-fit: contain;
  border-radius: 24px;
}

.product-header h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 1;
}

.product-header p {
  font-size: 1.3rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.features {
  max-width: 1100px;
  margin: 5rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2.5rem;
}

.feature-card {
  background: var(--bg-card);
  padding: 2.5rem;
  border-radius: 20px;
  border: 1px solid var(--border-color);
  box-shadow: 0 8px 30px var(--shadow);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px var(--shadow);
}

.feature-card h3 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.6;
}

.download-section {
  text-align: center;
  padding: 5rem 2rem;
  background: var(--bg-secondary);
  margin-top: 3rem;
}

.download-section h2 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.download-btn {
  display: inline-block;
  padding: 1.2rem 2.5rem;
  border-radius: 15px;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.1rem;
  transition: all 0.3s ease;
  box-shadow: 0 8px 25px var(--shadow);
}

.download-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 35px var(--shadow);
}

.theme-music .download-btn {
  background: var(--music-gradient);
  color: white;
}

.theme-diary .download-btn {
  background: var(--diary-gradient);
  color: white;
}

.theme-data .download-btn {
  background: var(--data-gradient);
  color: white;
}

.privacy-container {
  max-width: 900px;
  margin: 4rem auto;
  padding: 3rem;
  background: var(--bg-card);
  border-radius: 20px;
  border: 1px solid var(--border-color);
  box-shadow: 0 8px 30px var(--shadow);
  line-height: 1.8;
}

.privacy-container h1, .privacy-container h2 {
  color: var(--text-primary);
  margin-bottom: 1.5rem;
}

.privacy-container p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

footer {
  background: var(--bg-secondary);
  padding: 4rem 2rem 3rem;
  text-align: center;
  border-top: 1px solid var(--border-color);
  margin-top: 4rem;
}

footer p {
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

footer a {
  color: var(--siv-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

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

/* About Page Styles */
.about-hero {
  padding: 5rem 2rem 4rem;
  text-align: center;
  background: var(--bg-secondary);
  position: relative;
}

.about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 80%, rgba(26, 35, 126, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, rgba(210, 105, 30, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 40% 40%, rgba(0, 245, 255, 0.05) 0%, transparent 70%);
}

.about-hero h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--siv-primary), var(--data-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  position: relative;
  z-index: 1;
}

.about-hero p {
  font-size: 1.3rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.about-content {
  max-width: 1000px;
  margin: 5rem auto;
  padding: 0 2rem;
  display: grid;
  gap: 3rem;
}

.about-section {
  background: var(--bg-card);
  padding: 3rem;
  border-radius: 20px;
  border: 1px solid var(--border-color);
  box-shadow: 0 8px 30px var(--shadow);
}

.about-section h2 {
  font-size: 2rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.about-section p {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.1rem;
}

.values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.value-card {
  padding: 2rem;
  background: var(--bg-secondary);
  border-radius: 16px;
  border: 1px solid var(--border-color);
}

.value-card h3 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.value-card p {
  color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 768px) {
  .theme-toggle {
    top: 15px;
    right: 15px;
    padding: 8px 16px;
    font-size: 12px;
  }

  .hero h1 {
    font-size: 2.8rem;
  }

  .hero .subtitle {
    font-size: 1.2rem;
  }

  .hero p {
    font-size: 1.1rem;
  }

  .nav-links {
    gap: 1rem;
    font-size: 0.9rem;
  }

  .logo {
    font-size: 1.5rem;
  }

  .app-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    margin: 3rem auto;
  }

  .app-card h3 {
    font-size: 1.4rem;
  }

  .about-hero h1 {
    font-size: 2.8rem;
  }

  .about-hero p {
    font-size: 1.1rem;
  }

  .product-header h1 {
    font-size: 2.8rem;
  }

  .product-icon {
    width: 160px;
    height: 160px;
  }

  .product-icon img {
    width: 120px;
    height: 120px;
  }

  .features {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .values-grid {
    grid-template-columns: 1fr;
  }

  nav {
    padding: 1rem 1rem;
  }

  .hero-content,
  .about-content,
  .features,
  .app-grid {
    padding: 0 1rem;
  }
}

@media (max-width: 480px) {
  .theme-toggle .text {
    display: none;
  }

  .theme-toggle {
    padding: 10px;
    border-radius: 50%;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

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

  .about-hero h1 {
    font-size: 2.2rem;
  }

  .nav-links {
    display: none;
  }
  
  .logo {
    margin: 0 auto;
  }

  nav {
    justify-content: center;
  }
}