/* AI-DAC Official Website */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --stone-950: #0c0a09;
  --stone-900: #1c1917;
  --stone-800: #292524;
  --stone-700: #44403c;
  --stone-600: #57534e;
  --stone-500: #78716c;
  --stone-400: #a8a29e;
  --stone-300: #d6d3d1;
  --stone-200: #e7e5e3;
  --white-5: rgba(255, 255, 255, 0.05);
  --white-10: rgba(255, 255, 255, 0.1);
  --white-20: rgba(255, 255, 255, 0.2);
  --white-30: rgba(255, 255, 255, 0.3);
  --white-50: rgba(255, 255, 255, 0.5);
  --white-80: rgba(255, 255, 255, 0.8);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  background: var(--stone-950);
  color: var(--stone-300);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ============================================================================
   Hero
   ============================================================================ */

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  text-align: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
  mix-blend-mode: overlay;
  filter: grayscale(1);
}

.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0.8),
    rgba(0, 0, 0, 0.5),
    var(--stone-950)
  );
}

.hero-content {
  position: relative;
  z-index: 10;
  padding: 0 1.5rem;
}

.hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  background: var(--white-5);
  border: 1px solid var(--white-10);
  backdrop-filter: blur(12px);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--white-80);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(4rem, 12vw, 9rem);
  font-weight: 900;
  letter-spacing: -0.05em;
  color: #fff;
  margin-bottom: 1rem;
  line-height: 1;
}

.hero-tagline {
  font-size: clamp(1.1rem, 3vw, 1.5rem);
  color: var(--stone-300);
  font-weight: 300;
  max-width: 640px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-tagline strong {
  color: #fff;
  font-weight: 700;
}

.hero-scroll {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.hero-scroll-line {
  width: 1px;
  height: 3rem;
  background: linear-gradient(
    to bottom,
    transparent,
    var(--white-50),
    transparent
  );
}

.hero-scroll-text {
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--white-30);
}

/* ============================================================================
   Concept
   ============================================================================ */

.concept {
  padding: 8rem 0;
  background: var(--stone-950);
}

.concept-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4rem;
  align-items: center;
}

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

.concept-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  color: #fff;
  margin-bottom: 2rem;
}

.concept-title-accent {
  color: var(--stone-600);
}

.concept-desc {
  font-size: 1.1rem;
  color: var(--stone-400);
  line-height: 1.8;
  max-width: 28rem;
}

.concept-desc strong {
  color: #fff;
}

.concept-cards {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.concept-card {
  padding: 2rem;
  border-radius: 1rem;
  background: var(--white-5);
  border: 1px solid var(--white-5);
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.concept-card-icon {
  flex-shrink: 0;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  background: var(--white-10);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.concept-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.5rem;
}

.concept-card p {
  font-size: 0.875rem;
  color: var(--stone-400);
  line-height: 1.6;
}

/* ============================================================================
   Features
   ============================================================================ */

.features {
  padding: 8rem 0;
  background: var(--stone-900);
  border-top: 1px solid var(--white-5);
}

.section-header {
  text-align: center;
  margin-bottom: 5rem;
}

.section-header h2 {
  font-size: 1.875rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1rem;
}

.section-header p {
  color: var(--stone-400);
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

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

.feature-card {
  position: relative;
  padding: 2rem;
  border-radius: 1.5rem;
  background: var(--stone-950);
  border: 1px solid var(--white-10);
  overflow: hidden;
  transition: transform 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-card-icon {
  width: 3rem;
  height: 3rem;
  background: #fff;
  color: #000;
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
}

.feature-card h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 1rem;
}

.feature-card p {
  font-size: 0.875rem;
  color: var(--stone-400);
  line-height: 1.6;
}

/* ============================================================================
   How It Works
   ============================================================================ */

.how-it-works {
  padding: 8rem 0;
  background: var(--stone-950);
  position: relative;
  overflow: hidden;
}

.how-it-works-bg {
  position: absolute;
  top: 0;
  right: 0;
  width: 500px;
  height: 500px;
  background: var(--white-5);
  border-radius: 50%;
  filter: blur(120px);
  transform: translate(50%, -50%);
  pointer-events: none;
}

.how-it-works h2 {
  font-size: 1.875rem;
  font-weight: 700;
  text-align: center;
  color: #fff;
  margin-bottom: 5rem;
}

.steps {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.step {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
}

.step-indicator {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.step-icon {
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  border: 1px solid var(--white-20);
  background: var(--stone-900);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.1rem;
  box-shadow: 0 0 15px rgba(255, 255, 255, 0.1);
}

.step-line {
  width: 1px;
  height: 4rem;
  background: var(--white-10);
}

.step:last-child .step-line {
  display: none;
}

.step-content {
  padding-top: 0.5rem;
}

.step-num {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--stone-500);
  letter-spacing: 0.15em;
  margin-bottom: 0.5rem;
}

.step-content h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.5rem;
}

.step-content p {
  font-size: 0.875rem;
  color: var(--stone-400);
  line-height: 1.6;
}

/* ============================================================================
   CTA
   ============================================================================ */

.cta {
  padding: 6rem 1.5rem;
  background: #fff;
  text-align: center;
}

.cta h2 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 900;
  color: #000;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.cta p {
  color: var(--stone-600);
  font-size: 1.1rem;
  margin-bottom: 2.5rem;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: #000;
  color: #fff;
  padding: 1.25rem 2.5rem;
  border-radius: 9999px;
  font-size: 1.2rem;
  font-weight: 700;
  box-shadow: 0 25px 50px rgba(0, 0, 0, 0.25);
  transition: background 0.2s;
}

.cta-button:hover {
  background: var(--stone-800);
}

.cta-button svg {
  width: 1.25rem;
  height: 1.25rem;
}

/* ============================================================================
   Footer
   ============================================================================ */

.footer {
  padding: 3rem 1.5rem;
  background: #000;
  text-align: center;
  border-top: 1px solid var(--white-10);
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 2rem;
  font-size: 0.75rem;
  font-weight: 500;
}

.footer-links a {
  color: var(--stone-500);
  transition: color 0.2s;
}

.footer-links a:hover {
  color: #fff;
}

.footer-copyright {
  color: var(--stone-600);
  font-size: 0.75rem;
  line-height: 1.8;
}

/* ============================================================================
   Legal Pages (Privacy & Terms)
   ============================================================================ */

.legal-page {
  min-height: 100vh;
  background: var(--stone-950);
  color: var(--stone-300);
}

.legal-header {
  padding: 6rem 0 3rem;
  text-align: center;
  border-bottom: 1px solid var(--white-5);
}

.legal-header h1 {
  font-size: 2.5rem;
  font-weight: 900;
  color: #fff;
  margin-bottom: 0.5rem;
}

.legal-header p {
  color: var(--stone-500);
  font-size: 0.875rem;
}

.legal-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 3rem 1.5rem 6rem;
}

.legal-content h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
  margin-top: 3rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--white-5);
}

.legal-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--stone-200);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.legal-content p {
  margin-bottom: 1rem;
  line-height: 1.8;
  font-size: 0.9375rem;
}

.legal-content ul,
.legal-content ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.legal-content li {
  margin-bottom: 0.5rem;
  line-height: 1.7;
  font-size: 0.9375rem;
}

.legal-content a {
  color: var(--stone-200);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.legal-content a:hover {
  color: #fff;
}

.legal-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--stone-400);
  font-size: 0.875rem;
  margin-bottom: 2rem;
  transition: color 0.2s;
}

.legal-back:hover {
  color: #fff;
}

/* ============================================================================
   Utility
   ============================================================================ */

@media (max-width: 767px) {
  .hero-title {
    font-size: 3.5rem;
  }
}