/* ============================================
   KeyForge Labs — Global Styles
   Where Musical Fluency Is Forged.
   ============================================ */

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

:root {
  /* Brand palette */
  --kf-bg:          #0b0e14;
  --kf-bg-raised:   #111622;
  --kf-bg-card:     #161c2a;
  --kf-border:      #1e2738;
  --kf-text:        #e0e4ec;
  --kf-text-muted:  #8a93a8;
  --kf-teal:        #2dd4bf;
  --kf-indigo:      #6366f1;
  --kf-gradient:    linear-gradient(135deg, var(--kf-teal), var(--kf-indigo));
  --kf-gradient-h:  linear-gradient(90deg, var(--kf-teal), var(--kf-indigo));
  --kf-white:       #ffffff;

  /* Typography */
  --font-sans:  'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:  'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  /* Spacing scale */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  --space-5xl: 8rem;

  /* Layout */
  --max-width: 1120px;
  --nav-height: 72px;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--kf-bg);
  color: var(--kf-text);
  line-height: 1.7;
  min-height: 100vh;
}

a {
  color: var(--kf-teal);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--kf-white);
}

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

/* --- Typography --- */
h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.25;
  color: var(--kf-white);
}

h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.25rem); }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.5rem); }
h4 { font-size: 1.125rem; }

p {
  max-width: 640px;
}

.gradient-text {
  background: var(--kf-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.section {
  padding: var(--space-5xl) 0;
}

.section--alt {
  background-color: var(--kf-bg-raised);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(11, 14, 20, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--kf-border);
  z-index: 1000;
  transition: background 0.3s ease;
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--kf-white);
  text-decoration: none;
}

.nav__logo-icon {
  width: 32px;
  height: 32px;
  background: var(--kf-gradient);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--kf-bg);
  font-weight: 800;
}

.nav__logo-img {
  height: 28px;
  width: auto;
}

.hero__logo {
  max-width: 400px;
  height: auto;
  margin: 0 auto var(--space-xl);
  filter: brightness(1.3);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  list-style: none;
}

.nav__links a {
  color: var(--kf-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color 0.2s ease;
}

.nav__links a:hover,
.nav__links a.active {
  color: var(--kf-white);
}

.nav__links .btn--primary {
  color: var(--kf-bg);
}

.nav__links .btn--primary:hover {
  color: var(--kf-bg);
}

.nav__mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--kf-text);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--space-sm);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn--primary {
  background: var(--kf-gradient);
  color: var(--kf-bg);
}

.btn--primary:hover {
  opacity: 0.9;
  color: var(--kf-bg);
  transform: translateY(-1px);
}

.btn--secondary {
  background: transparent;
  color: var(--kf-text-muted);
  border: 1px solid var(--kf-border);
}

.btn--secondary:hover {
  border-color: var(--kf-teal);
  color: var(--kf-white);
}

.btn--ghost {
  background: transparent;
  color: var(--kf-teal);
  padding: 0.5rem 0;
}

.btn--ghost:hover {
  color: var(--kf-white);
}

.btn--ghost::after {
  content: ' →';
}

/* --- Hero --- */
.hero {
  padding-top: calc(var(--nav-height) + var(--space-5xl));
  padding-bottom: var(--space-5xl);
  text-align: center;
}

.hero h1 {
  margin-bottom: var(--space-lg);
}

.hero__subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--kf-text-muted);
  max-width: 560px;
  margin: 0 auto var(--space-sm);
  line-height: 1.7;
}

.hero__tagline {
  font-size: 0.95rem;
  color: var(--kf-text-muted);
  opacity: 0.7;
  margin-bottom: var(--space-2xl);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero__actions {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Cards --- */
.card {
  background: var(--kf-bg-card);
  border: 1px solid var(--kf-border);
  border-radius: 12px;
  padding: var(--space-xl);
  transition: border-color 0.2s ease;
}

.card:hover {
  border-color: var(--kf-teal);
}

/* --- Feature Grid --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.feature-card__icon {
  font-size: 1.5rem;
  margin-bottom: var(--space-md);
}

.feature-card h3 {
  margin-bottom: var(--space-sm);
}

.feature-card p {
  color: var(--kf-text-muted);
  font-size: 0.95rem;
}

/* --- Screenshot Showcase --- */
.screenshot-showcase {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-xl);
  align-items: start;
}

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

@media (max-width: 700px) {
  .screenshot-showcase--2col {
    grid-template-columns: 1fr;
  }
}

.screenshot-item {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--kf-border);
  background: var(--kf-bg-card);
}

.screenshot-item img {
  width: 100%;
  transition: transform 0.3s ease;
}

.screenshot-item:hover img {
  transform: scale(1.02);
}

.screenshot-item__caption {
  padding: var(--space-md) var(--space-lg);
  font-size: 0.85rem;
  color: var(--kf-text-muted);
}

/* --- Phone Frame --- */
.phone-frame {
  max-width: 280px;
  margin: 0 auto;
  border-radius: 28px;
  overflow: hidden;
  border: 2px solid var(--kf-border);
  background: var(--kf-bg-card);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.4);
}

.phone-frame img {
  width: 100%;
  display: block;
}

/* --- Desktop Frame --- */
.desktop-frame {
  border-radius: 12px;
  overflow: hidden;
  border: 2px solid var(--kf-border);
  background: var(--kf-bg-card);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.3);
}

.desktop-frame img {
  width: 100%;
  display: block;
}

/* --- Product Section --- */
.product-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.product-section--reverse {
  direction: rtl;
}

.product-section--reverse > * {
  direction: ltr;
}

.product-section__content h2 {
  margin-bottom: var(--space-sm);
}

.product-section__tagline {
  color: var(--kf-teal);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}

.product-section__content p {
  color: var(--kf-text-muted);
  margin-bottom: var(--space-lg);
}

.product-section__screenshots {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
}

/* --- Values / Pillars --- */
.values-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xl);
}

.value-card {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  flex: 0 1 300px;
  max-width: 340px;
}

.value-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
}

.value-card h3 {
  margin-bottom: var(--space-sm);
}

.value-card p {
  color: var(--kf-text-muted);
  font-size: 0.95rem;
  margin: 0 auto;
}

/* --- Manifesto Block --- */
.manifesto {
  text-align: center;
  padding: var(--space-5xl) 0;
}

.manifesto p {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--kf-text-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 2;
}

.manifesto p strong {
  color: var(--kf-white);
}

/* --- CTA Banner --- */
.cta-banner {
  text-align: center;
  padding: var(--space-5xl) 0;
  background: var(--kf-bg-raised);
  border-top: 1px solid var(--kf-border);
  border-bottom: 1px solid var(--kf-border);
}

.cta-banner h2 {
  margin-bottom: var(--space-sm);
}

.cta-banner p {
  color: var(--kf-text-muted);
  margin: 0 auto var(--space-xl);
  font-size: 1.1rem;
}

/* --- FAQ --- */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--kf-border);
  padding: var(--space-xl) 0;
}

.faq-item:first-child {
  border-top: 1px solid var(--kf-border);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--kf-white);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.25rem;
  color: var(--kf-text-muted);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item__answer {
  padding-top: var(--space-md);
  color: var(--kf-text-muted);
  font-size: 0.95rem;
  line-height: 1.8;
  max-width: 640px;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--kf-border);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-2xl);
}

.footer__brand p {
  color: var(--kf-text-muted);
  font-size: 0.85rem;
  margin-top: var(--space-sm);
  max-width: 280px;
}

.footer__links {
  display: flex;
  gap: var(--space-3xl);
}

.footer__col h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--kf-text-muted);
  margin-bottom: var(--space-md);
}

.footer__col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer__col a {
  color: var(--kf-text-muted);
  font-size: 0.9rem;
}

.footer__col a:hover {
  color: var(--kf-white);
}

.footer__bottom {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--kf-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--kf-text-muted);
}

.footer__legal {
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  font-size: 0.75rem;
  color: var(--kf-text-muted);
  opacity: 0.7;
  text-align: center;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.6;
}

/* --- Download Cards --- */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
  max-width: 900px;
  margin: 0 auto;
}

.download-card {
  text-align: center;
  padding: var(--space-2xl);
}

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

.download-card h3 {
  margin-bottom: var(--space-sm);
}

.download-card p {
  color: var(--kf-text-muted);
  font-size: 0.9rem;
  margin: 0 auto var(--space-lg);
}

/* --- About --- */
.about-content {
  max-width: 720px;
  margin: 0 auto;
}

.about-content h2 {
  margin-top: var(--space-3xl);
  margin-bottom: var(--space-md);
}

.about-content h2:first-child {
  margin-top: 0;
}

.about-content p {
  color: var(--kf-text-muted);
  margin-bottom: var(--space-lg);
  max-width: 100%;
}

.about-content p strong {
  color: var(--kf-white);
}

/* --- Divider --- */
.divider {
  width: 64px;
  height: 2px;
  background: var(--kf-gradient-h);
  border: none;
  margin: var(--space-3xl) auto;
}

/* --- Audience Grid --- */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-lg);
  text-align: center;
}

.audience-item {
  padding: var(--space-xl);
}

.audience-item__icon {
  font-size: 1.75rem;
  margin-bottom: var(--space-sm);
}

.audience-item h4 {
  margin-bottom: var(--space-xs);
}

.audience-item p {
  color: var(--kf-text-muted);
  font-size: 0.9rem;
  margin: 0 auto;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--kf-bg);
    border-bottom: 1px solid var(--kf-border);
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-lg);
  }

  .nav__links.open {
    display: flex;
  }

  .nav__mobile-toggle {
    display: block;
  }

  .product-section {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .product-section--reverse {
    direction: ltr;
  }

  .product-section__screenshots {
    order: -1;
  }

  .hero {
    padding-top: calc(var(--nav-height) + var(--space-3xl));
    padding-bottom: var(--space-3xl);
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .footer__inner {
    flex-direction: column;
  }

  .footer__links {
    flex-direction: column;
    gap: var(--space-xl);
  }

  .footer__bottom {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero__actions {
    flex-direction: column;
    align-items: center;
  }

  .phone-frame {
    max-width: 220px;
  }
}