/**
 * PCheckAI Premium Design System
 * CloudFlare Pages Support Site Styles
 * Material Design 3 based with premium aesthetics
 */

/* ============================================
   CSS Variables - Design Tokens
   ============================================ */
:root {
  /* Primary - Soft Rose/Blush */
  --color-primary-main: #E8A5B3;
  --color-primary-light: #FDF2F4;
  --color-primary-dark: #C4788A;
  
  /* Secondary - Soft Periwinkle Blue */
  --color-secondary-main: #A5B4E8;
  --color-secondary-light: #F2F4FD;
  --color-secondary-dark: #7889C4;
  
  /* Surface Colors */
  --color-surface-bg: #FAFBFD;
  --color-surface-card: #FFFFFF;
  --color-surface-glass: rgba(255, 255, 255, 0.85);
  
  /* Text Colors */
  --color-text-primary: #1A1B1F;
  --color-text-secondary: #5C5E66;
  --color-text-tertiary: #9498A0;
  --color-text-inverse: #FFFFFF;
  
  /* Border Colors */
  --color-border-default: #EBEDF0;
  --color-border-subtle: rgba(0, 0, 0, 0.04);
  
  /* Status Colors */
  --color-success: #5CB85C;
  --color-success-light: #E8F5E8;
  --color-warning: #F5A623;
  --color-error: #E85C5C;
  
  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #FFF5F7 0%, #F8F0FF 100%);
  --gradient-primary: linear-gradient(135deg, #E8A5B3 0%, #D4909F 100%);
  --gradient-secondary: linear-gradient(135deg, #A5B4E8 0%, #909FD4 100%);
  --gradient-premium: linear-gradient(135deg, #FDF2F4 0%, #F2F4FD 100%);
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 0.75rem;
  --space-lg: 1rem;
  --space-xl: 1.25rem;
  --space-2xl: 1.5rem;
  --space-3xl: 2rem;
  --space-4xl: 3rem;
  --space-5xl: 4rem;
  --space-6xl: 5rem;
  
  /* Border Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-jp: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", YuGothic, Meiryo, sans-serif;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 12px 24px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 4px 20px rgba(232, 165, 179, 0.25);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-jp), var(--font-sans);
  background: var(--color-surface-bg);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

/* ============================================
   Language-specific Font Adjustments
   ============================================ */
html[lang="en"] body {
  font-family: var(--font-sans);
  line-height: 1.5;
}

/* ============================================
   Layout Components
   ============================================ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

@media (min-width: 640px) {
  .container {
    padding: 0 var(--space-2xl);
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-3xl);
  }
}

/* ============================================
   Header
   ============================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--color-surface-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-subtle);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.header-logo img {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.header-logo span {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-primary);
  letter-spacing: -0.02em;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.header-nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

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

.language-switcher {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-surface-bg);
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border-default);
}

.language-switcher a {
  font-size: 0.75rem;
  font-weight: 600;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.language-switcher a.active {
  background: var(--color-primary-main);
  color: var(--color-text-inverse);
}

.language-switcher a:not(.active):hover {
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  padding-top: 64px;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 100%;
  background: radial-gradient(ellipse, rgba(232, 165, 179, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 50%;
  height: 80%;
  background: radial-gradient(ellipse, rgba(165, 180, 232, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4xl);
  align-items: center;
  padding: var(--space-5xl) 0;
  position: relative;
  z-index: 1;
}

@media (min-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr 1fr;
  }
}

.hero-content {
  max-width: 560px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  background: var(--color-surface-card);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: var(--space-xl);
  box-shadow: var(--shadow-sm);
}

.hero-badge svg {
  width: 14px;
  height: 14px;
  color: var(--color-success);
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--color-text-primary);
  margin-bottom: var(--space-lg);
}

.hero-title-accent {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-3xl);
}

.hero-disclaimer {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--radius-lg);
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-top: var(--space-xl);
}

.hero-disclaimer svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--color-text-tertiary);
}

/* Hero Visual */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-app-icon {
  width: 280px;
  height: 280px;
  border-radius: var(--radius-2xl);
  box-shadow: 
    0 25px 50px -12px rgba(232, 165, 179, 0.25),
    0 0 0 1px rgba(255, 255, 255, 0.5) inset;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

.hero-decorations {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.decoration-circle {
  position: absolute;
  border-radius: 50%;
  opacity: 0.5;
}

.decoration-circle-1 {
  width: 120px;
  height: 120px;
  background: rgba(232, 165, 179, 0.2);
  top: 10%;
  right: 10%;
  animation: pulse 4s ease-in-out infinite;
}

.decoration-circle-2 {
  width: 80px;
  height: 80px;
  background: rgba(165, 180, 232, 0.2);
  bottom: 20%;
  left: 5%;
  animation: pulse 4s ease-in-out infinite 1s;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.1); opacity: 0.3; }
}

/* ============================================
   App Store Buttons
   ============================================ */
.store-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.store-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-text-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  font-weight: 600;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
}

.store-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.store-button svg {
  width: 24px;
  height: 24px;
}

.store-button-secondary {
  background: var(--color-surface-card);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-default);
}

.store-button-secondary:hover {
  background: var(--color-surface-bg);
}

/* ============================================
   Features Section
   ============================================ */
.features {
  padding: var(--space-6xl) 0;
  background: var(--color-surface-bg);
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--space-4xl);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary-dark);
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  margin-bottom: var(--space-md);
}

.section-description {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}

@media (min-width: 640px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-card {
  background: var(--color-surface-card);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  border: 1px solid var(--color-border-subtle);
  transition: all var(--transition-normal);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-default);
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
  color: var(--color-text-inverse);
}

.feature-icon svg {
  width: 28px;
  height: 28px;
}

.feature-icon.secondary {
  background: var(--gradient-secondary);
}

.feature-icon.tertiary {
  background: linear-gradient(135deg, #C4A5E8 0%, #B090D4 100%);
}

.feature-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-sm);
}

.feature-description {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ============================================
   How It Works Section
   ============================================ */
.how-it-works {
  padding: var(--space-6xl) 0;
  background: var(--gradient-premium);
}

.steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
  counter-reset: step;
}

@media (min-width: 768px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
  }
}

.step {
  position: relative;
  text-align: center;
}

@media (min-width: 768px) {
  .step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 40px;
    right: -50%;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--color-border-default) 50%, transparent);
    z-index: 0;
  }
}

.step-number {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--color-surface-card);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-lg);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-md);
  position: relative;
  z-index: 1;
  border: 2px solid var(--color-primary-light);
}

.step-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.step-description {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  max-width: 280px;
  margin: 0 auto;
}

/* ============================================
   Learn Section
   ============================================ */
.learn {
  padding: var(--space-6xl) 0;
  background: var(--color-surface-bg);
}

.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

@media (min-width: 640px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.article-card {
  display: flex;
  align-items: flex-start;
  gap: var(--space-lg);
  padding: var(--space-xl);
  background: var(--color-surface-card);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-subtle);
  transition: all var(--transition-normal);
}

.article-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-default);
}

.article-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--color-primary-dark);
}

.article-icon svg {
  width: 24px;
  height: 24px;
}

.article-content {
  flex: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.article-category {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary-dark);
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-primary-light);
  border-radius: var(--radius-sm);
}

.article-readtime {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.article-readtime svg {
  width: 12px;
  height: 12px;
}

.article-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-xs);
}

.article-subtitle {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* ============================================
   Stats Section
   ============================================ */
.stats {
  padding: var(--space-4xl) 0;
  background: var(--color-surface-card);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
}

@media (min-width: 640px) {
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.stat-item {
  text-align: center;
}

.stat-value {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  padding: var(--space-4xl) 0 var(--space-2xl);
  background: var(--color-text-primary);
  color: var(--color-text-tertiary);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-3xl);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer-brand {
  max-width: 300px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.footer-logo img {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-md);
}

.footer-logo span {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-text-inverse);
}

.footer-description {
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: var(--space-lg);
}

.footer-heading {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-inverse);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--space-sm);
}

.footer-links a {
  font-size: 0.875rem;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  padding-top: var(--space-2xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  align-items: center;
  text-align: center;
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

.footer-copyright {
  font-size: 0.8125rem;
}

.footer-disclaimer {
  font-size: 0.75rem;
  max-width: 600px;
  opacity: 0.8;
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out forwards;
}

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

/* Stagger animations */
.feature-card:nth-child(1) { animation-delay: 0.1s; }
.feature-card:nth-child(2) { animation-delay: 0.2s; }
.feature-card:nth-child(3) { animation-delay: 0.3s; }
.feature-card:nth-child(4) { animation-delay: 0.4s; }
.feature-card:nth-child(5) { animation-delay: 0.5s; }
.feature-card:nth-child(6) { animation-delay: 0.6s; }

/* ============================================
   Utility Classes
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.text-center { text-align: center; }
.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ============================================
   Mobile Menu Toggle (Hidden by default)
   ============================================ */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .header-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface-glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border-subtle);
  }
  
  .header-nav.open {
    display: flex;
  }
  
  .hero-app-icon {
    width: 200px;
    height: 200px;
  }
}