/* ========================================
   HabitCoach Landing Page - Global Styles
   ======================================== */

/* CSS Variables */
:root {
  /* Colors */
  --color-primary: #6366F1;
  --color-primary-dark: #4F46E5;
  --color-primary-light: #818CF8;
  --color-accent: #10B981;
  --color-accent-dark: #059669;

  --color-bg: #FFFFFF;
  --color-bg-alt: #F9FAFB;
  --color-bg-dark: #111827;

  --color-text: #111827;
  --color-text-secondary: #6B7280;
  --color-text-light: #9CA3AF;
  --color-text-inverse: #FFFFFF;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #6366F1 0%, #8B5CF6 100%);
  --gradient-hero: linear-gradient(180deg, #F9FAFB 0%, #FFFFFF 100%);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  --spacing-3xl: 6rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

  /* Typography */
  --font-family: 'Noto Sans TC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;

  /* Container */
  --container-max: 1200px;
  --container-padding: 1.5rem;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

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

/* ========================================
   Header
   ======================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-weight: 700;
  font-size: var(--font-size-xl);
  color: var(--color-text);
}

.header__logo-icon {
  font-size: 1.5rem;
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.header__nav-link {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.header__nav-link:hover {
  color: var(--color-primary);
}

/* Language Switcher */
.lang-switcher {
  position: relative;
}

.lang-switcher__btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--color-bg-alt);
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-switcher__btn:hover {
  border-color: var(--color-primary-light);
  color: var(--color-primary);
}

.lang-switcher__dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: var(--spacing-xs);
  background: var(--color-bg);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--transition-fast);
}

.lang-switcher:hover .lang-switcher__dropdown,
.lang-switcher__dropdown:focus-within {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-switcher__option {
  display: block;
  padding: var(--spacing-xs) var(--spacing-md);
  color: var(--color-text-secondary);
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.lang-switcher__option:hover {
  background: var(--color-bg-alt);
  color: var(--color-primary);
}

.lang-switcher__option.active {
  color: var(--color-primary);
  font-weight: 500;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
  padding: calc(4rem + var(--spacing-3xl)) 0 var(--spacing-3xl);
  background: var(--gradient-hero);
  overflow: hidden;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
}

.hero__content {
  max-width: 540px;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: rgba(99, 102, 241, 0.1);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
}

.hero__title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.7;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

/* Phone Mockup */
.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.phone-mockup {
  position: relative;
  width: 280px;
  height: 580px;
  background: linear-gradient(180deg, #1F2937 0%, #111827 100%);
  border-radius: 40px;
  padding: 12px;
  box-shadow: var(--shadow-xl), 0 0 0 1px rgba(255, 255, 255, 0.1) inset;
}

.phone-mockup::before {
  content: '';
  position: absolute;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 24px;
  background: #000;
  border-radius: 20px;
}

.phone-mockup__screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, #6366F1 0%, #8B5CF6 50%, #A78BFA 100%);
  border-radius: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: white;
  text-align: center;
  padding: var(--spacing-lg);
}

.phone-mockup__icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
}

.phone-mockup__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.phone-mockup__text {
  font-size: var(--font-size-sm);
  opacity: 0.9;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  font-weight: 600;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn--primary {
  background: var(--gradient-primary);
  color: var(--color-text-inverse);
  box-shadow: var(--shadow-md), 0 0 0 0 rgba(99, 102, 241, 0.5);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), 0 0 20px 0 rgba(99, 102, 241, 0.3);
  color: var(--color-text-inverse);
}

.btn--secondary {
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid rgba(0, 0, 0, 0.1);
}

.btn--secondary:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn--disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

/* ========================================
   Features Section
   ======================================== */
.features {
  padding: var(--spacing-3xl) 0;
  background: var(--color-bg);
}

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-2xl);
}

.section-header__title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.section-header__subtitle {
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
}

.feature-card {
  padding: var(--spacing-lg);
  background: var(--color-bg);
  border: 1px solid rgba(0, 0, 0, 0.05);
  border-radius: var(--radius-xl);
  transition: all var(--transition-base);
}

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

.feature-card__icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(99, 102, 241, 0.1);
  border-radius: var(--radius-lg);
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
}

.feature-card__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
}

.feature-card__desc {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.6;
}

/* ========================================
   Why Section
   ======================================== */
.why {
  padding: var(--spacing-3xl) 0;
  background: var(--color-bg-alt);
}

.why__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}

.why-card {
  padding: var(--spacing-xl);
  background: var(--color-bg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  text-align: center;
}

.why-card__icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
}

.why-card__title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.why-card__desc {
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ========================================
   Premium Section
   ======================================== */
.premium {
  padding: var(--spacing-3xl) 0;
  background: var(--color-bg);
}

.premium__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
  align-items: center;
}

.premium__content {
  max-width: 480px;
}

.premium__badge {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: linear-gradient(135deg, #FCD34D 0%, #F59E0B 100%);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: #78350F;
  margin-bottom: var(--spacing-md);
}

.premium__title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.premium__list {
  list-style: none;
  margin-bottom: var(--spacing-lg);
}

.premium__list-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-xs) 0;
  color: var(--color-text-secondary);
}

.premium__list-item::before {
  content: '✓';
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--color-accent);
  color: white;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: bold;
}

.premium__visual {
  display: flex;
  justify-content: center;
}

.premium-card {
  background: var(--gradient-primary);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  color: white;
  text-align: center;
  max-width: 320px;
  box-shadow: var(--shadow-xl);
}

.premium-card__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.premium-card__price {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  margin-bottom: var(--spacing-xs);
}

.premium-card__period {
  font-size: var(--font-size-sm);
  opacity: 0.8;
  margin-bottom: var(--spacing-lg);
}

.premium-card__features {
  list-style: none;
  text-align: left;
  margin-bottom: var(--spacing-lg);
}

.premium-card__features li {
  padding: var(--spacing-xs) 0;
  font-size: var(--font-size-sm);
}

.premium-card__features li::before {
  content: '✓ ';
  font-weight: bold;
}

/* ========================================
   CTA Section
   ======================================== */
.cta {
  padding: var(--spacing-3xl) 0;
  background: var(--color-bg-dark);
  color: var(--color-text-inverse);
  text-align: center;
}

.cta__title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.cta__subtitle {
  color: var(--color-text-light);
  margin-bottom: var(--spacing-lg);
  font-size: var(--font-size-lg);
}

/* ========================================
   Footer
   ======================================== */
.footer {
  padding: var(--spacing-xl) 0;
  background: var(--color-bg-dark);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer__copyright {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
}

.footer__links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer__link {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-text-inverse);
}

/* ========================================
   Legal Pages (Privacy & Terms)
   ======================================== */
.legal {
  padding: calc(4rem + var(--spacing-2xl)) 0 var(--spacing-3xl);
  min-height: 100vh;
}

.legal__header {
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.legal__title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
}

.legal__updated {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.legal__content {
  max-width: 800px;
}

.legal__content h2 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

.legal__content h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.legal__content p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

.legal__content ul, .legal__content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
  color: var(--color-text-secondary);
}

.legal__content li {
  margin-bottom: var(--spacing-xs);
  line-height: 1.7;
}

.legal__content a {
  color: var(--color-primary);
}

.legal__content a:hover {
  text-decoration: underline;
}

.legal__content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--spacing-lg);
}

.legal__content th,
.legal__content td {
  padding: var(--spacing-sm);
  text-align: left;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.legal__content th {
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-bg-alt);
}

.legal__content td {
  color: var(--color-text-secondary);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__content {
    max-width: 100%;
  }

  .hero__cta {
    justify-content: center;
  }

  .hero__visual {
    order: -1;
  }

  .phone-mockup {
    width: 240px;
    height: 500px;
  }

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

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

  .premium__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .premium__content {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.75rem;
    --font-size-2xl: 1.25rem;
  }

  .header__nav {
    gap: var(--spacing-sm);
  }

  .hero {
    padding-top: calc(4rem + var(--spacing-xl));
  }

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

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

  .footer__inner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .phone-mockup {
    width: 200px;
    height: 420px;
    border-radius: 32px;
  }

  .phone-mockup::before {
    width: 60px;
    height: 20px;
    top: 16px;
  }

  .phone-mockup__screen {
    border-radius: 24px;
  }

  .btn {
    width: 100%;
  }

  .hero__cta {
    flex-direction: column;
  }
}