/* ===== CSS Custom Properties ===== */
:root {
  --color-primary: #007AFF;
  --color-primary-dark: #0056CC;
  --color-background: #FFFFFF;
  --color-background-alt: #F8F9FA;
  --color-text-primary: #1C1C1E;
  --color-text-secondary: #6B7280;
  --color-border: #E5E7EB;
  --color-header-bg: rgba(255, 255, 255, 0.9);
  --color-footer-bg: #1C1C1E;

  --font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 5rem;

  --max-width: 1200px;
  --border-radius: 16px;
  --border-radius-sm: 8px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.15);
}

/* Dark mode */
[data-theme="dark"] {
  --color-primary: #0A84FF;
  --color-primary-dark: #409CFF;
  --color-background: #000000;
  --color-background-alt: #1C1C1E;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #A1A1A6;
  --color-border: #38383A;
  --color-header-bg: rgba(0, 0, 0, 0.9);
  --color-footer-bg: #000000;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.6);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  -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 0.2s ease;
}

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

/* ===== Typography ===== */
h1, h2, h3 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text-primary);
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 1.75rem;
}

h3 {
  font-size: 1.25rem;
}

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

/* ===== Layout ===== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 1rem;
  font-weight: 600;
  color: white;
  background-color: var(--color-primary);
  border: none;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.btn:hover {
  background-color: var(--color-primary-dark);
  color: white;
  transform: translateY(-1px);
}

.btn-small {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.875rem;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
  border-radius: var(--border-radius-sm);
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.2s ease;
}

.theme-toggle:hover {
  background-color: var(--color-background-alt);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  display: none;
}

/* Show sun icon in dark mode (to switch to light) */
[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}

/* Show moon icon in light mode (to switch to dark) */
:root:not([data-theme="dark"]) .theme-toggle .icon-moon {
  display: block;
}

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

/* ===== Theme-aware images ===== */
.theme-light {
  display: block;
}

.theme-dark {
  display: none;
}

[data-theme="dark"] .theme-light {
  display: none;
}

[data-theme="dark"] .theme-dark {
  display: block;
}

.screenshot {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ===== App Store Badge ===== */
.app-store-link {
  display: inline-block;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.app-store-link:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}

.app-store-badge {
  height: 54px;
  width: auto;
}

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: var(--color-header-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

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

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

.logo-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-primary);
}

/* ===== Hero Section ===== */
.hero {
  padding: calc(64px + var(--spacing-2xl)) 0 var(--spacing-2xl);
  background: linear-gradient(180deg, var(--color-background-alt) 0%, var(--color-background) 100%);
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-xl);
  text-align: center;
}

.hero-text {
  max-width: 600px;
}

.hero-text h1 {
  margin-bottom: var(--spacing-md);
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-lg);
  color: var(--color-text-secondary);
}

/* ===== Device Mockup ===== */
.device-mockup {
  position: relative;
  background: linear-gradient(145deg, #2C2C2E 0%, #1C1C1E 100%);
  border-radius: 44px;
  padding: 12px;
  box-shadow: var(--shadow-xl);
}

.device-mockup.iphone {
  width: 280px;
}

.device-mockup.ipad {
  width: 420px;
  border-radius: 24px;
  padding: 10px;
}

.device-screen {
  background-color: #000;
  border-radius: 32px;
  overflow: hidden;
  aspect-ratio: 9 / 19.5;
}

.device-mockup.ipad .device-screen {
  border-radius: 16px;
  aspect-ratio: 4 / 3;
}

.device-mockup.ipad .screenshot {
  object-fit: fill;
}

.screenshot-placeholder {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--color-primary) 0%, #5856D6 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1rem;
  font-weight: 600;
}

.screenshot-placeholder span {
  opacity: 0.8;
}

/* ===== Key Features Section ===== */
.key-features {
  padding: var(--spacing-2xl) 0;
  background-color: var(--color-background);
}

.features-duo {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
}

.feature-card {
  background-color: var(--color-background-alt);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius);
  text-align: center;
}

.feature-card-large .feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  background-color: var(--color-primary);
  color: white;
  border-radius: 16px;
  margin-bottom: var(--spacing-md);
}

.feature-card h2 {
  margin-bottom: var(--spacing-sm);
}

/* ===== Features Grid Section ===== */
.features-grid-section {
  padding: var(--spacing-2xl) 0;
  background-color: var(--color-background-alt);
}

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

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

.feature-item {
  text-align: center;
  padding: var(--spacing-md);
}

.feature-icon-small {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background-color: rgba(0, 122, 255, 0.1);
  color: var(--color-primary);
  border-radius: 12px;
  margin-bottom: var(--spacing-sm);
}

.feature-item h3 {
  margin-bottom: var(--spacing-xs);
}

.feature-item p {
  font-size: 1rem;
}

/* ===== Screenshots Section ===== */
.screenshots-section {
  padding: var(--spacing-2xl) 0;
  background-color: var(--color-background);
  overflow: hidden;
}

.screenshots-gallery {
  display: flex;
  gap: var(--spacing-lg);
  overflow-x: auto;
  padding: var(--spacing-md) 0;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.screenshot-item {
  flex-shrink: 0;
  scroll-snap-align: center;
  text-align: center;
}

.screenshot-caption {
  margin-top: var(--spacing-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-secondary);
}

/* ===== Privacy Section ===== */
.privacy-section {
  padding: var(--spacing-2xl) 0;
  background-color: var(--color-background-alt);
}

.privacy-content {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

.privacy-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  background-color: rgba(0, 122, 255, 0.1);
  color: var(--color-primary);
  border-radius: 20px;
  margin-bottom: var(--spacing-md);
}

.privacy-content h2 {
  margin-bottom: var(--spacing-sm);
}

/* ===== Download Section ===== */
.download-section {
  padding: var(--spacing-2xl) 0;
  background: linear-gradient(135deg, var(--color-primary) 0%, #5856D6 100%);
  color: white;
}

.download-content {
  text-align: center;
}

.download-content h2 {
  color: white;
  margin-bottom: var(--spacing-xs);
}

.download-content p {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--spacing-lg);
}

/* ===== Footer ===== */
.site-footer {
  padding: var(--spacing-xl) 0;
  background-color: var(--color-footer-bg);
  color: rgba(255, 255, 255, 0.7);
}

.footer-content {
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: white;
}

.footer-copyright {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.5);
}

/* ===== Responsive Design ===== */

/* Tablet */
@media (min-width: 640px) {
  h1 {
    font-size: 3rem;
  }

  h2 {
    font-size: 2rem;
  }

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

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

  .device-mockup.iphone {
    width: 300px;
  }

  .device-mockup.ipad {
    width: 480px;
  }

  .screenshots-gallery {
    justify-content: center;
    flex-wrap: wrap;
  }
}

/* Desktop */
@media (min-width: 1024px) {
  h1 {
    font-size: 3.5rem;
  }

  .hero-content {
    flex-direction: row;
    text-align: left;
    justify-content: space-between;
  }

  .hero-text {
    flex: 1;
    max-width: 550px;
  }

  .hero-device {
    flex-shrink: 0;
  }

  .device-mockup.iphone {
    width: 320px;
  }

  .device-mockup.ipad {
    width: 540px;
  }

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

  .feature-item {
    text-align: left;
  }

  .feature-icon-small {
    margin-bottom: var(--spacing-md);
  }
}

/* Large screens */
@media (min-width: 1280px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

/* Hide scrollbar but keep functionality */
.screenshots-gallery::-webkit-scrollbar {
  display: none;
}

.screenshots-gallery {
  -ms-overflow-style: none;
  scrollbar-width: none;
}