/* ==========================================================================
   Transform Text AI — Landing Page Styles
   Typography-first, minimal, Dieter Rams-inspired
   ========================================================================== */

/* --- Custom Properties --- */
:root {
  /* Colors */
  --color-text: #111;
  --color-bg: #FAFAFA;
  --color-accent: #0098EA;
  --color-accent-hover: #007bc4;
  --color-muted: #666;
  --color-border: #E0E0E0;
  --color-card-bg: #FFF;
  --color-placeholder-bg: #F0F0F0;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-size-hero: clamp(2.5rem, 5vw, 4rem);
  --font-size-section: clamp(1.75rem, 3vw, 2.5rem);
  --font-size-body: clamp(1rem, 1.5vw, 1.125rem);
  --font-size-small: 0.875rem;
  --font-size-nav: 0.9375rem;
  --line-height-tight: 1.15;
  --line-height-body: 1.7;

  /* Spacing */
  --section-padding: clamp(80px, 10vw, 120px);
  --content-max-width: 720px;
  --nav-height: 64px;

  /* Transitions */
  --transition-fast: 0.2s ease;
}

/* --- Base --- */
body {
  font-family: var(--font-family);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-text);
  background-color: var(--color-bg);
}

/* --- Layout --- */
.container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: var(--section-padding) 0;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  transition: background-color var(--transition-fast), box-shadow var(--transition-fast);
}

.nav--scrolled {
  background-color: rgba(250, 250, 250, 0.95);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  box-shadow: 0 1px 0 var(--color-border);
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 960px;
}

.nav__logo {
  font-size: var(--font-size-nav);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav__cta {
  font-size: var(--font-size-small);
  font-weight: 600;
  color: var(--color-accent);
  padding: 8px 20px;
  border: 1.5px solid var(--color-accent);
  border-radius: 6px;
  transition: opacity var(--transition-fast);
}

.nav__cta:hover {
  opacity: 0.75;
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  font-weight: 600;
  font-size: var(--font-size-body);
  border-radius: 8px;
  padding: 14px 32px;
  transition: opacity var(--transition-fast);
  cursor: pointer;
  border: none;
}

.btn:hover {
  opacity: 0.8;
}

.btn--primary {
  background-color: var(--color-accent);
  color: #FFF;
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

/* --- Hero --- */
.hero {
  padding-top: calc(var(--nav-height) + var(--section-padding));
  text-align: center;
}

.hero__headline {
  font-size: var(--font-size-hero);
  font-weight: 800;
  line-height: var(--line-height-tight);
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}

.hero__subheadline {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--color-muted);
  line-height: 1.6;
  max-width: 560px;
  margin: 0 auto 40px;
}

.hero__buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Section Headings --- */
.section-headline {
  font-size: var(--font-size-section);
  font-weight: 700;
  line-height: var(--line-height-tight);
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-subheadline {
  color: var(--color-muted);
  margin-bottom: 48px;
}

/* Centered section headers */
.text-center {
  text-align: center;
}

/* --- What It Does — Style Cards --- */
.style-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 48px;
}

.style-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
}

.style-card__icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: block;
}

.style-card__label {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.style-card__desc {
  color: var(--color-muted);
  font-size: var(--font-size-small);
  line-height: 1.6;
}

/* --- Why We Built It --- */
.why p {
  color: var(--color-muted);
  margin-bottom: 20px;
  max-width: 600px;
}

.why p:last-child {
  margin-bottom: 0;
}

/* --- How It Works — GIF Placeholder --- */
.gif-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: var(--color-placeholder-bg);
  border: 2px dashed var(--color-border);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-muted);
  font-size: var(--font-size-body);
  margin-top: 48px;
}

/* --- Steps --- */
.steps-list {
  margin-top: 48px;
  display: grid;
  gap: 32px;
}

.step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 24px;
  align-items: start;
}

.step__number {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
  color: var(--color-accent);
  letter-spacing: -0.03em;
}

.step__text {
  padding-top: 4px;
}

.step__title {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 4px;
}

.step__desc {
  color: var(--color-muted);
  font-size: var(--font-size-small);
}

/* --- Pricing --- */
.pricing-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-top: 48px;
}

.pricing-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
  position: relative;
}

.pricing-card--featured {
  border-color: var(--color-accent);
  border-width: 2px;
}

.pricing-card__badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-accent);
  color: #FFF;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 20px;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.pricing-card__amount {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}

.pricing-card__unit {
  font-size: var(--font-size-small);
  color: var(--color-muted);
  font-weight: 500;
}

.pricing-card__credits {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 12px;
}

.pricing-note {
  text-align: center;
  color: var(--color-muted);
  font-size: var(--font-size-small);
  margin-top: 32px;
}

/* --- Footer --- */
.footer {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer__wordmark {
  font-weight: 700;
  font-size: var(--font-size-nav);
  margin-bottom: 8px;
}

.footer__links {
  margin-bottom: 16px;
}

.footer__links a {
  color: var(--color-accent);
  font-size: var(--font-size-small);
  transition: opacity var(--transition-fast);
}

.footer__links a:hover {
  opacity: 0.75;
}

.footer__copy {
  color: var(--color-muted);
  font-size: var(--font-size-small);
}

.footer__tagline {
  color: var(--color-muted);
  font-size: var(--font-size-small);
  margin-top: 8px;
}

/* ==========================================================================
   Responsive — Desktop (768px+)
   ========================================================================== */
@media (min-width: 768px) {
  .style-cards {
    grid-template-columns: repeat(3, 1fr);
  }

  .pricing-cards {
    grid-template-columns: repeat(4, 1fr);
  }

  .step {
    grid-template-columns: 80px 1fr;
  }

  .step__number {
    font-size: 3rem;
  }
}