/* CSS Custom Properties - Dark Mode (Default) */
:root {
  --color-bg: #1a1a1a;
  --color-bg-elevated: #242424;
  --color-text: #ffffff;
  --color-text-light: #b3b3b3;
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-border: #333333;
  --color-border-focus: #3b82f6;
  --color-placeholder: #808080;
  --color-success: #10b981;
  --color-error: #ef4444;
  --max-width: 900px;
  --spacing-xs: 1rem;
  --spacing-sm: 2rem;
  --spacing-md: 4rem;
  --spacing-lg: 6rem;
  --spacing-xl: 8rem;
  --transition-base: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-theme: 0.3s ease;
}

/* Light Mode - Respects system preference */
@media (prefers-color-scheme: light) {
  :root {
    --color-bg: #fafafa;
    --color-bg-elevated: #ffffff;
    --color-text: #1a1a1a;
    --color-text-light: #4a4a4a;
    --color-accent: #0066cc;
    --color-accent-hover: #0052a3;
    --color-border: #e5e5e5;
    --color-border-focus: #0066cc;
    --color-placeholder: #999;
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  font-size: 16px;
  letter-spacing: -0.01em;
  transition: background-color var(--transition-theme), color var(--transition-theme);
}

/* Site Header */
.site-header {
  padding: var(--spacing-xs) var(--spacing-xs);
  border-bottom: 1px solid var(--color-border);
  background-color: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color var(--transition-theme), border-color var(--transition-theme);
}

.site-header__link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-text);
  max-width: 1400px;
  margin: 0 auto;
  transition: opacity var(--transition-base);
}

.site-header__link:hover {
  opacity: 0.8;
}

.site-header__logo {
  width: 32px;
  height: 32px;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header__title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

@media (max-width: 768px) {
  .site-header {
    padding: 0.75rem var(--spacing-xs);
  }
  
  .site-header__logo {
    width: 28px;
    height: 28px;
  }
  
  .site-header__title {
    font-size: 1.125rem;
  }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

/* Layout */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-xs);
}

.main-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  align-items: start;
}

@media (min-width: 1024px) {
  .main-content {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
  }
}

.content-column {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  padding-top: var(--spacing-sm);
}

@media (min-width: 1024px) {
  .content-column {
    padding-top: var(--spacing-md);
  }
}

.carousel-column {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: var(--spacing-md);
}

@media (min-width: 1024px) {
  .carousel-column {
    align-items: center;
    padding-top: var(--spacing-lg);
  }
}

/* Hero Section */
.hero {
  padding: 0;
  text-align: left;
}

.hero__title {
  font-size: clamp(2.5rem, 8vw, 4rem);
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.03em;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.hero__title.visible {
  opacity: 1;
  transform: translateY(0);
}

.hero__tagline {
  font-size: clamp(1.25rem, 4vw, 1.5rem);
  font-weight: 400;
  color: var(--color-text-light);
  letter-spacing: -0.01em;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out 0.2s, transform 0.6s ease-out 0.2s;
}

.hero__tagline.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Explanation Section */
.explanation {
  padding: 0;
  text-align: left;
}

.explanation__text {
  font-size: clamp(1rem, 2.5vw, 1.125rem);
  line-height: 1.75;
  color: var(--color-text-light);
  max-width: 90%;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.explanation__text.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Carousel Section */
.carousel-section {
  padding: 0;
  margin: 0;
  position: relative;
  overflow: hidden;
  width: 100%;
}

.carousel-wrapper {
  position: relative;
  width: 100%;
  margin: 0 auto;
}

.carousel-container {
  width: 100%;
  overflow: visible;
  position: relative;
  perspective: 1000px;
  height: 650px;
  display: flex;
  align-items: center;
  justify-content: center;
}

@media (min-width: 1024px) {
  .carousel-container {
    height: 750px;
  }
}

.carousel-track {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
}

.carousel-item {
  position: absolute;
  width: min(240px, 35vw);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0;
  transform: translateX(0) translateZ(-200px) scale(0.7);
  filter: blur(8px);
  pointer-events: none;
}

@media (min-width: 1024px) {
  .carousel-item {
    width: min(280px, 20vw);
  }
}

.carousel-item.active {
  opacity: 1;
  transform: translateX(0) translateZ(0) scale(1);
  filter: blur(0);
  z-index: 10;
  pointer-events: auto;
}

.carousel-item.prev {
  opacity: 0.6;
  transform: translateX(-140px) translateZ(-150px) scale(0.8);
  filter: blur(4px);
  z-index: 5;
}

.carousel-item.next {
  opacity: 0.6;
  transform: translateX(140px) translateZ(-150px) scale(0.8);
  filter: blur(4px);
  z-index: 5;
}

.carousel-item.far-prev {
  opacity: 0.3;
  transform: translateX(-240px) translateZ(-250px) scale(0.6);
  filter: blur(12px);
  z-index: 1;
}

.carousel-item.far-next {
  opacity: 0.3;
  transform: translateX(240px) translateZ(-250px) scale(0.6);
  filter: blur(12px);
  z-index: 1;
}

.carousel-image {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
  object-fit: contain;
  border: 2px solid var(--color-border);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
  transition: all var(--transition-smooth);
  background-color: var(--color-bg-elevated);
  image-rendering: -webkit-optimize-contrast;
  image-rendering: crisp-edges;
  image-rendering: auto;
}

.carousel-item.active .carousel-image {
  border-color: var(--color-text-light);
  border-width: 2px;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.4);
}

@media (prefers-color-scheme: light) {
  .carousel-image {
    border: 2px solid rgba(0, 0, 0, 0.12);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    background-color: #ffffff;
  }
  .carousel-item.active .carousel-image {
    border-color: rgba(0, 0, 0, 0.2);
    border-width: 2px;
    box-shadow: 0 24px 64px rgba(0, 0, 0, 0.12);
  }
}

.carousel-item:hover .carousel-image {
  border-color: rgba(0, 0, 0, 0.1);
}

/* Carousel Navigation */
.carousel-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1rem;
  position: relative;
  z-index: 20;
}

.carousel-arrow {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background-color: var(--color-bg-elevated);
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  transition: all var(--transition-smooth);
  font-family: inherit;
  padding: 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.carousel-arrow:hover {
  background-color: var(--color-text);
  color: var(--color-bg);
  border-color: var(--color-text);
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

@media (prefers-color-scheme: light) {
  .carousel-arrow {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  }
  .carousel-arrow:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
  }
}

.carousel-arrow:active {
  transform: scale(0.98);
}

.carousel-arrow:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.2);
}

.carousel-arrow:disabled {
  opacity: 0.3;
  cursor: not-allowed;
  transform: none;
}

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  align-items: center;
}

.carousel-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-text);
  border: none;
  cursor: pointer;
  transition: all var(--transition-smooth);
  padding: 0;
  opacity: 0.25;
}

.carousel-dot.active {
  opacity: 1;
  width: 24px;
  border-radius: 4px;
  background-color: var(--color-text);
}

.carousel-dot:hover:not(.active) {
  opacity: 0.5;
  transform: scale(1.2);
}

.carousel-dot:focus {
  outline: none;
  opacity: 0.6;
}

/* Email Section */
.email-section {
  padding: 0;
  text-align: left;
}

.email-form {
  max-width: 100%;
  margin: 0;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.email-form.visible {
  opacity: 1;
  transform: translateY(0);
}

.email-input {
  width: 100%;
  padding: 0.875rem 1rem;
  font-size: 1rem;
  border: 1px solid var(--color-border);
  background-color: var(--color-bg-elevated);
  color: var(--color-text);
  margin-bottom: var(--spacing-xs);
  font-family: inherit;
  border-radius: 6px;
  transition: all var(--transition-base);
  outline: none;
}

.email-input:hover {
  border-color: var(--color-text-light);
}

.email-input:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

@media (prefers-color-scheme: light) {
  .email-input:focus {
    box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1);
  }
}

.email-input::placeholder {
  color: var(--color-placeholder);
  opacity: 0.7;
}

.email-submit {
  width: 100%;
  padding: 0.875rem 1rem;
  font-size: 1rem;
  background-color: var(--color-text);
  color: var(--color-bg);
  border: none;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  border-radius: 6px;
  transition: all var(--transition-base);
  margin-bottom: var(--spacing-xs);
  letter-spacing: -0.01em;
}

.email-submit:hover {
  background-color: var(--color-text-light);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

@media (prefers-color-scheme: light) {
  .email-submit:hover {
    background-color: #0a0a0a;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }
}

.email-submit:active {
  transform: translateY(0);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.email-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.email-consent {
  font-size: 0.875rem;
  color: var(--color-placeholder);
  line-height: 1.5;
}

.email-consent__link {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: all var(--transition-base);
}

.email-consent__link:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

.email-consent__link:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.form-message {
  margin-top: var(--spacing-xs);
  font-size: 0.875rem;
  min-height: 1.5rem;
  padding: 0.5rem 0;
  transition: all var(--transition-base);
}

.form-message.success {
  color: var(--color-text);
  font-weight: 500;
}

.form-message.error {
  color: var(--color-error);
  font-weight: 500;
}

/* Footer */
.footer {
  padding: var(--spacing-md) var(--spacing-xs);
  text-align: center;
  border-top: 1px solid var(--color-border);
  margin-top: var(--spacing-xl);
  max-width: 1400px;
  margin-left: auto;
  margin-right: auto;
  transition: border-color var(--transition-theme);
}

.footer__text {
  margin-bottom: 0.5rem;
}

.footer__link {
  color: var(--color-text-light);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: all var(--transition-base);
}

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

.footer__link:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.footer__copyright {
  font-size: 0.875rem;
  color: var(--color-placeholder);
  margin-top: 0.5rem;
}

/* Privacy Page */
.privacy {
  padding: var(--spacing-xl) 0;
  max-width: 700px;
  margin: 0 auto;
}

.privacy__title {
  font-size: clamp(2rem, 6vw, 3rem);
  margin-bottom: var(--spacing-xs);
  text-align: center;
}

.privacy__updated {
  text-align: center;
  color: var(--color-placeholder);
  font-size: 0.875rem;
  margin-bottom: var(--spacing-md);
}

.privacy__content {
  line-height: 1.7;
}

.privacy__content h2 {
  font-size: 1.5rem;
  margin-top: var(--spacing-md);
  margin-bottom: var(--spacing-xs);
}

.privacy__content h2:first-of-type {
  margin-top: 0;
}

.privacy__content p {
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
  line-height: 1.7;
}

.privacy__content ul {
  margin-bottom: var(--spacing-sm);
  padding-left: 1.5rem;
  color: var(--color-text);
  line-height: 1.7;
}

.privacy__content ul ul {
  margin-top: 0.5rem;
  margin-bottom: 0.5rem;
  padding-left: 1.5rem;
}

.privacy__content li {
  margin-bottom: 0.5rem;
}

.privacy__content a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: all var(--transition-base);
}

.privacy__content a:hover {
  color: var(--color-accent-hover);
  text-decoration-color: var(--color-accent-hover);
}

.privacy__content strong {
  font-weight: 600;
  color: var(--color-text);
}

.privacy__back {
  margin-top: var(--spacing-lg);
  text-align: center;
}

.privacy__link {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: opacity 0.2s ease;
}

.privacy__link:hover {
  opacity: 0.7;
}

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

/* Responsive Design */
@media (max-width: 1023px) {
  .main-content {
    grid-template-columns: 1fr;
  }

  .hero {
    text-align: center;
  }

  .explanation {
    text-align: center;
  }

  .email-section {
    text-align: center;
  }

  .carousel-container {
    height: 550px;
    perspective: 800px;
  }

  .carousel-item {
    width: min(220px, 40vw);
  }

  .carousel-item.prev {
    transform: translateX(-100px) translateZ(-100px) scale(0.75);
  }

  .carousel-item.next {
    transform: translateX(100px) translateZ(-100px) scale(0.75);
  }

  .carousel-item.far-prev {
    transform: translateX(-180px) translateZ(-150px) scale(0.5);
  }

  .carousel-item.far-next {
    transform: translateX(180px) translateZ(-150px) scale(0.5);
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-xs: 0.75rem;
    --spacing-sm: 1.5rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
  }

  main {
    padding: var(--spacing-sm) var(--spacing-xs);
  }

  .carousel-container {
    height: 500px;
    perspective: 600px;
  }

  .carousel-item {
    width: min(200px, 45vw);
  }

  .carousel-item.prev {
    transform: translateX(-80px) translateZ(-80px) scale(0.7);
  }

  .carousel-item.next {
    transform: translateX(80px) translateZ(-80px) scale(0.7);
  }

  .carousel-item.far-prev,
  .carousel-item.far-next {
    opacity: 0;
  }

  .carousel-nav {
    gap: 1rem;
  }

  .carousel-arrow {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .carousel-container {
    height: 480px;
  }

  .carousel-item {
    width: min(180px, 50vw);
  }
}

/* No JavaScript Fallback */
.no-js .carousel-container {
  overflow-x: auto;
  height: auto;
  perspective: none;
}

.no-js .carousel-track {
  display: flex;
  flex-direction: row;
  gap: 1rem;
  overflow-x: auto;
  position: relative;
  transform-style: flat;
}

.no-js .carousel-item {
  position: relative;
  opacity: 1;
  transform: none;
  filter: none;
  flex: 0 0 auto;
  width: min(320px, 80vw);
}

.no-js .carousel-nav {
  display: none;
}

.no-js .carousel-dots {
  display: none;
}

.no-js .hero__title,
.no-js .hero__tagline,
.no-js .explanation__text,
.no-js .email-form {
  opacity: 1;
  transform: none;
}