/* ========================================
   Life Emergence - Apple Design Style
   Common Stylesheet
   ======================================== */

/* ---- CSS Reset & Base ---- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* Apple Color System */
  --apple-blue: #007AFF;
  --apple-green: #34C759;
  --apple-orange: #FF9500;
  --apple-red: #FF3B30;
  
  /* Gray Scale */
  --gray-1: #1d1d1f;
  --gray-2: #424245;
  --gray-3: #6e6e73;
  --gray-4: #86868b;
  --gray-5: #aeaeb2;
  --gray-6: #d2d2d7;
  --gray-7: #e5e5ea;
  --gray-8: #f2f2f7;
  --gray-9: #f5f5f7;
  
  /* Background */
  --bg-primary: #f5f5f7;
  --bg-glass: rgba(255, 255, 255, 0.72);
  
  /* Typography */
  --font-sf: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 48px;
  --spacing-2xl: 64px;
  
  /* Border */
  --border-thin: 0.5px solid rgba(0, 0, 0, 0.12);
  --border-standard: 1px solid rgba(0, 0, 0, 0.08);
  
  /* Shadow */
  --shadow-subtle: 0 0.5px 1px rgba(0, 0, 0, 0.04),
                   0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.08),
                   0 1px 4px rgba(0, 0, 0, 0.04);
  --shadow-elevated: 0 8px 32px rgba(0, 0, 0, 0.12),
                     0 2px 8px rgba(0, 0, 0, 0.06);
  
  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-2xl: 24px;
  --radius-3xl: 32px;
  
  /* Layout */
  --max-width: 1200px;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-sf);
  color: var(--gray-1);
  background-color: var(--bg-primary);
  line-height: 1.5;
  letter-spacing: -0.01em;
  min-height: 100vh;
}

/* ---- Typography ---- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }

p {
  color: var(--gray-2);
  line-height: 1.6;
}

a {
  color: var(--apple-blue);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.7;
}

/* ---- Glass Effect ---- */
.glass {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: var(--border-thin);
  border-radius: var(--radius-lg);
}

/* ---- Navigation ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 0 var(--spacing-md);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: var(--border-thin);
  transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-subtle);
}

.navbar__brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-1);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.navbar__brand:hover {
  opacity: 1;
}

.navbar__logo {
  height: 32px;
  width: auto;
}

.navbar__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  list-style: none;
}

.navbar__link {
  color: var(--gray-2);
  font-size: 0.9rem;
  font-weight: 500;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  position: relative;
}

.navbar__link:hover {
  color: var(--gray-1);
  background: rgba(0, 0, 0, 0.04);
  opacity: 1;
}

.navbar__link.active {
  color: var(--apple-blue);
}

/* Apple Segmented Control */
.segmented-control {
  display: inline-flex;
  padding: 2px;
  background: var(--gray-8);
  border-radius: var(--radius-sm);
  gap: 2px;
}

.segmented-control__item {
  padding: 6px 16px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--gray-3);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
  border: none;
  background: transparent;
  font-family: var(--font-sf);
}

.segmented-control__item.active {
  background: white;
  color: var(--gray-1);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 12px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-sf);
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.2, 0.8, 0.2, 1);
  letter-spacing: -0.01em;
}

.btn--primary {
  background: var(--apple-blue);
  color: white;
}

.btn--primary:hover {
  background: #0066CC;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 122, 255, 0.3);
  opacity: 1;
}

.btn--secondary {
  background: var(--gray-8);
  color: var(--gray-1);
}

.btn--secondary:hover {
  background: var(--gray-7);
  opacity: 1;
}

.btn--ghost {
  background: transparent;
  color: var(--apple-blue);
}

.btn--ghost:hover {
  background: rgba(0, 122, 255, 0.08);
  opacity: 1;
}

/* ---- Cards ---- */
.card {
  background: white;
  border-radius: var(--radius-xl);
  border: var(--border-thin);
  box-shadow: var(--shadow-subtle);
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-medium);
}

.card__body {
  padding: var(--spacing-lg);
}

.card__title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--gray-1);
}

.card__text {
  color: var(--gray-3);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ---- Container ---- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ---- Section ---- */
.section {
  padding: var(--spacing-2xl) 0;
}

.section__header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section__title {
  margin-bottom: var(--spacing-sm);
}

.section__subtitle {
  font-size: 1.125rem;
  color: var(--gray-4);
  max-width: 600px;
  margin: 0 auto;
}

/* ---- Grid ---- */
.grid {
  display: grid;
  gap: var(--spacing-md);
}

.grid--2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid--3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid--4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ---- Footer ---- */
.footer {
  background: var(--gray-1);
  color: var(--gray-5);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-2xl);
}

.footer__content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
  margin-bottom: var(--spacing-sm);
}

.footer__description {
  color: var(--gray-4);
  font-size: 0.9rem;
  line-height: 1.6;
  max-width: 300px;
}

.footer__title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-5);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-md);
}

.footer__links {
  list-style: none;
}

.footer__links li {
  margin-bottom: var(--spacing-xs);
}

.footer__links a {
  color: var(--gray-4);
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

.footer__links a:hover {
  color: white;
  opacity: 1;
}

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-md);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer__content {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
  }
  
  .navbar {
    padding: 0 var(--spacing-sm);
  }
  
  .navbar__nav {
    gap: var(--spacing-xs);
  }
  
  .navbar__link {
    font-size: 0.85rem;
    padding: var(--spacing-xs) var(--spacing-xs);
  }
  
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
  }
  
  .footer__content {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .footer__bottom {
    flex-direction: column;
    gap: var(--spacing-sm);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .navbar__brand span {
    display: none;
  }
  
  .section__title {
    font-size: 1.75rem;
  }
}

/* ---- Animations ---- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

.animate-fade-in {
  animation: fadeIn 0.4s ease forwards;
}

/* Staggered animation */
.animate-delay-1 { animation-delay: 0.1s; opacity: 0; }
.animate-delay-2 { animation-delay: 0.2s; opacity: 0; }
.animate-delay-3 { animation-delay: 0.3s; opacity: 0; }
.animate-delay-4 { animation-delay: 0.4s; opacity: 0; }

/* ---- Utility ---- */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

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

.hidden { display: none; }
.visible { display: block; }