/* ============================================
   CircadianShield — Marketing Website Styles
   ============================================ */

/* --- Custom Properties --- */
:root {
  --color-bg: #0a0e27;
  --color-bg-light: #111538;
  --color-bg-card: #141937;
  --color-accent: #f59e0b;
  --color-accent-hover: #d97706;
  --color-accent-glow: rgba(245, 158, 11, 0.15);
  --color-text: #f0f0f0;
  --color-text-muted: #9ca3af;
  --color-text-dim: #6b7280;
  --color-border: #1e2448;
  --color-indigo: #6366f1;
  --color-indigo-muted: rgba(99, 102, 241, 0.15);
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", Menlo, monospace;
  --max-width: 1200px;
  --nav-height: 72px;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.25s ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  background-color: var(--color-bg);
  overflow-x: hidden;
  scrollbar-color: var(--color-border) var(--color-bg);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-stack);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  min-height: 100vh;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-hover);
}

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

ul,
ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  font-weight: 700;
}

/* --- Utility --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  box-sizing: border-box;
}

img, svg, video {
  max-width: 100%;
  height: auto;
}

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

.section {
  padding: 80px 0;
}

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

.section__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  margin-bottom: 16px;
}

.section__subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 640px;
}

.section__header {
  text-align: center;
  margin-bottom: 48px;
}

.section__header .section__subtitle {
  margin: 0 auto;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font-stack);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  line-height: 1;
}

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

.btn--primary:hover {
  background: var(--color-accent-hover);
  color: var(--color-bg);
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(245, 158, 11, 0.25);
}

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

.btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn--sm {
  padding: 10px 20px;
  font-size: 0.875rem;
}

.btn--lg {
  padding: 18px 36px;
  font-size: 1.125rem;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(10, 14, 39, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
}

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

.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

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

.nav__logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--color-accent), #f97316);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav__link {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition);
  position: relative;
}

.nav__link:hover,
.nav__link--active {
  color: var(--color-text);
}

.nav__link--active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
}

.nav__cta {
  margin-left: 8px;
}

/* Hamburger */
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

.nav__hamburger[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav__hamburger[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav__hamburger[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Hero --- */
.hero {
  padding-top: calc(var(--nav-height) + 80px);
  padding-bottom: 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(ellipse, rgba(245, 158, 11, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--color-accent-glow);
  border: 1px solid rgba(245, 158, 11, 0.2);
  border-radius: 100px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: 24px;
}

.hero__title {
  font-size: clamp(2.25rem, 6vw, 3.75rem);
  max-width: 800px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, var(--color-text) 40%, var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero__subtitle {
  font-size: clamp(1.0625rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 36px;
}

.hero__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.hero__image {
  max-width: 560px;
  margin: 0 auto;
  position: relative;
}

.hero__image img,
.hero__image svg {
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}

/* --- Problem Section --- */
.problem {
  text-align: center;
}

.problem__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: 32px;
  margin-top: 40px;
}

.problem__item {
  padding: 32px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.problem__icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 16px;
  background: rgba(239, 68, 68, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.problem__item h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.problem__item p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* --- How It Works --- */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
  gap: 32px;
  counter-reset: step;
}

.step {
  text-align: center;
  padding: 40px 24px;
  position: relative;
}

.step__number {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  background: var(--color-accent-glow);
  border: 2px solid var(--color-accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-accent);
}

.step h3 {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.step p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

/* --- Feature Cards --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(320px, 100%), 1fr));
  gap: 24px;
}

.feature-card {
  padding: 32px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: rgba(245, 158, 11, 0.3);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.feature-card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  background: var(--color-accent-glow);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.375rem;
}

.feature-card h3 {
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  line-height: 1.65;
}

/* --- Science Callout --- */
.callout {
  background: linear-gradient(135deg, var(--color-bg-card), var(--color-bg-light));
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.callout::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
}

.callout__tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-indigo);
  background: var(--color-indigo-muted);
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: 16px;
}

.callout h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 12px;
}

.callout p {
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto 24px;
}

/* --- Platform Badges --- */
.platforms {
  text-align: center;
}

.platforms__grid {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.platform-badge {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 32px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  min-width: 260px;
  text-decoration: none;
  transition: all var(--transition);
}

.platform-badge:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}

.platform-badge__icon {
  font-size: 2rem;
}

.platform-badge__text {
  text-align: left;
}

.platform-badge__label {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.platform-badge__name {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
}

/* --- Footer --- */
.footer {
  background: var(--color-bg-light);
  border-top: 1px solid var(--color-border);
  padding: 48px 0 32px;
}

.footer__inner {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 40px;
}

.footer__brand p {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-top: 12px;
  max-width: 280px;
}

.footer__col h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-dim);
  margin-bottom: 16px;
}

.footer__col ul li {
  margin-bottom: 10px;
}

.footer__col ul a {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

.footer__col ul a:hover {
  color: var(--color-text);
}

.footer__bottom {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-dim);
  font-size: 0.8125rem;
}

/* --- Features Page --- */
.feature-detail {
  padding: 48px 0;
  border-bottom: 1px solid var(--color-border);
}

.feature-detail:last-child {
  border-bottom: none;
}

.feature-detail__icon {
  width: 64px;
  height: 64px;
  background: var(--color-accent-glow);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 16px;
}

.feature-detail__content h2 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.feature-detail__content p {
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

.feature-detail__visual {
  display: none;
}

.feature-detail__list {
  list-style: none;
  padding: 0;
}

.feature-detail__list li {
  position: relative;
  padding-left: 24px;
  margin-bottom: 8px;
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}

.feature-detail__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0.6;
}

/* --- Science Page --- */
.science-section {
  padding: 48px 0;
  border-bottom: 1px solid var(--color-border);
}

.science-section:last-child {
  border-bottom: none;
}

.science-section h2 {
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.science-section p {
  color: var(--color-text-muted);
  line-height: 1.75;
  max-width: 800px;
  margin-bottom: 16px;
}

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

.science-callout-box {
  background: var(--color-bg-card);
  border-left: 3px solid var(--color-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 20px 24px;
  margin: 20px 0;
}

.science-callout-box p {
  margin-bottom: 0;
  font-style: italic;
  color: var(--color-text);
}

.science-ref {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
  font-style: normal;
  display: block;
  margin-top: 8px;
}

/* --- FAQ --- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

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

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-size: 1.0625rem;
  font-weight: 600;
  font-family: var(--font-stack);
  color: var(--color-text);
  transition: color var(--transition);
}

.faq-question:hover {
  color: var(--color-accent);
}

.faq-question__icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  margin-left: 16px;
  position: relative;
}

.faq-question__icon::before,
.faq-question__icon::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  background: var(--color-text-muted);
  border-radius: 1px;
  transition: transform var(--transition);
}

.faq-question__icon::before {
  width: 14px;
  height: 2px;
  transform: translate(-50%, -50%);
}

.faq-question__icon::after {
  width: 2px;
  height: 14px;
  transform: translate(-50%, -50%);
}

.faq-item[aria-expanded="true"] .faq-question__icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}

.faq-answer__inner {
  padding: 0 0 20px;
  color: var(--color-text-muted);
  line-height: 1.7;
  font-size: 0.9375rem;
}

.faq-item[aria-expanded="true"] .faq-answer {
  max-height: 500px;
}

/* --- Download Page --- */
.download-hero {
  text-align: center;
  padding-top: calc(var(--nav-height) + 60px);
  padding-bottom: 60px;
}

.download-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 32px;
  max-width: 800px;
  margin: 0 auto;
}

.download-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
}

.download-card--featured {
  border-color: var(--color-accent);
  position: relative;
}

.download-card--featured::before {
  content: "Available Now";
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-accent);
  color: var(--color-bg);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 16px;
  border-radius: 100px;
}

.download-card__icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.download-card h2 {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.download-card__version {
  color: var(--color-text-dim);
  font-size: 0.875rem;
  margin-bottom: 24px;
}

.download-card .btn {
  width: 100%;
  margin-bottom: 24px;
}

.download-card__reqs {
  text-align: left;
}

.download-card__reqs h4 {
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-dim);
  margin-bottom: 8px;
}

.download-card__reqs li {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  padding: 4px 0;
  padding-left: 20px;
  position: relative;
}

.download-card__reqs li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-size: 0.75rem;
}

/* --- Page Header (shared across subpages) --- */
.page-header {
  text-align: center;
  padding-top: calc(var(--nav-height) + 60px);
  padding-bottom: 40px;
}

.page-header__title {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: 12px;
}

.page-header__subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Responsive: Mobile --- */
@media (max-width: 768px) {
  .section {
    padding: 56px 0;
  }

  .nav__links {
    display: none;
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    z-index: 999;
  }

  .nav__links--open {
    display: flex;
  }

  .nav__cta {
    margin-left: 0;
  }

  .nav__hamburger {
    display: flex;
  }

  .hero {
    padding-top: calc(var(--nav-height) + 48px);
    padding-bottom: 48px;
  }

  .hero__title {
    font-size: clamp(1.75rem, 8vw, 2.5rem);
  }

  .hero__actions {
    flex-direction: column;
  }

  .hero__actions .btn {
    width: 100%;
    max-width: 320px;
  }

  .feature-detail {
    padding: 32px 0;
  }

  .footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer__brand {
    grid-column: 1 / -1;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .callout {
    padding: 32px 20px;
  }

  .download-cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 375px) {
  .container {
    padding: 0 16px;
  }

  .footer__inner {
    grid-template-columns: 1fr;
  }
}

/* --- Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-in {
  animation: fadeInUp 0.5s ease forwards;
  opacity: 0;
}

.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }
.animate-in:nth-child(5) { animation-delay: 0.4s; }
.animate-in:nth-child(6) { animation-delay: 0.5s; }

/* --- Language Switcher --- */
.nav__lang {
  display: flex;
  align-items: center;
  margin-left: 8px;
}

.nav__lang select {
  appearance: none;
  -webkit-appearance: none;
  background: var(--color-bg-card);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px 28px 6px 10px;
  font-size: 0.85rem;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: var(--transition);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%239ca3af' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.nav__lang select:hover,
.nav__lang select:focus {
  border-color: var(--color-accent);
  color: var(--color-text);
  outline: none;
}

/* RTL support for Arabic */
[dir="rtl"] .nav__links { direction: rtl; }
[dir="rtl"] .footer__inner { direction: rtl; }

@media (max-width: 768px) {
  .nav__lang {
    margin: 12px 0 0;
    justify-content: center;
  }
}