/* =============================================================================
   Stratus AI Limited — main.css
   ============================================================================= */

/* =============================================================================
   1. DESIGN TOKENS
   ============================================================================= */

:root {
  /* Colours */
  --bg:           #0A0A0F;
  --surface:      #13131A;
  --surface-2:    #1A1A24;
  --border:       #1E1E2E;
  --border-light: #2A2A3E;
  --accent:       #2563EB;
  --accent-light: #3B82F6;
  --text-primary: #F0F0F5;
  --text-secondary: #888899;
  --text-muted:   #3A3A50;
  --white:        #FFFFFF;

  /* Typography */
  --font:         'DM Sans', system-ui, -apple-system, sans-serif;
  --weight-regular: 400;
  --weight-medium:  500;
  --weight-semibold: 600;
  --weight-bold:  700;

  /* Spacing */
  --section-y:    clamp(64px, 10vw, 120px);
  --section-y-sm: clamp(40px, 6vw, 72px);
  --container:    1200px;
  --gutter:       clamp(20px, 4vw, 48px);

  /* Radius */
  --radius-sm:    4px;
  --radius:       8px;
  --radius-lg:    16px;

  /* Transitions */
  --transition:   0.2s ease;
  --transition-md: 0.35s ease;
}

/* =============================================================================
   2. RESET & BASE
   ============================================================================= */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: 17px;
  font-weight: var(--weight-regular);
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

ul, ol {
  list-style: none;
}

button, input, textarea, select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: none;
}

/* =============================================================================
   3. TYPOGRAPHY SCALE
   ============================================================================= */

.display {
  font-size: clamp(40px, 6vw, 80px);
  font-weight: var(--weight-bold);
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.heading-1 {
  font-size: clamp(32px, 4.5vw, 60px);
  font-weight: var(--weight-bold);
  line-height: 1.1;
  letter-spacing: -0.025em;
}

.heading-2 {
  font-size: clamp(24px, 3vw, 40px);
  font-weight: var(--weight-bold);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.heading-3 {
  font-size: clamp(18px, 2vw, 24px);
  font-weight: var(--weight-semibold);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.lead {
  font-size: clamp(17px, 1.8vw, 21px);
  font-weight: var(--weight-regular);
  line-height: 1.65;
  color: var(--text-secondary);
}

.label {
  font-size: 11px;
  font-weight: var(--weight-semibold);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

/* =============================================================================
   4. LAYOUT UTILITIES
   ============================================================================= */

.container {
  width: 100%;
  max-width: var(--container);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.container--narrow {
  max-width: 800px;
}

.container--wide {
  max-width: 1400px;
}

.section {
  padding-top: var(--section-y);
  padding-bottom: var(--section-y);
}

.section--sm {
  padding-top: var(--section-y-sm);
  padding-bottom: var(--section-y-sm);
}

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

.section--surface {
  background-color: var(--surface);
}

.section--border-top {
  border-top: 1px solid var(--border);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.gap-8  { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.gap-24 { gap: 24px; }
.gap-32 { gap: 32px; }
.gap-48 { gap: 48px; }

.mt-8   { margin-top: 8px; }
.mt-12  { margin-top: 12px; }
.mt-16  { margin-top: 16px; }
.mt-20  { margin-top: 20px; }
.mt-24  { margin-top: 24px; }
.mt-32  { margin-top: 32px; }
.mt-40  { margin-top: 40px; }
.mt-48  { margin-top: 48px; }
.mt-64  { margin-top: 64px; }

/* =============================================================================
   5. NAVIGATION
   ============================================================================= */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px 0;
  transition: background-color var(--transition-md), border-color var(--transition-md), padding var(--transition-md);
  border-bottom: 1px solid transparent;
}

.nav.is-scrolled {
  background-color: rgba(10, 10, 15, 0.96);
  border-bottom-color: var(--border);
  padding: 14px 0;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.nav__logo {
  font-size: 32px;
  font-weight: var(--weight-bold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-primary);
  flex-shrink: 0;
}

.nav__logo span {
  color: var(--accent);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav__link {
  font-size: 14px;
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition);
}

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

.nav__cta {
  font-size: 14px;
  font-weight: var(--weight-semibold);
  color: var(--text-primary);
  padding: 8px 18px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition), color var(--transition);
  flex-shrink: 0;
}

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

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  cursor: pointer;
}

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background-color: var(--text-primary);
  transition: transform var(--transition), opacity var(--transition);
}

.nav__hamburger.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}
.nav__hamburger.is-open span:nth-child(2) {
  opacity: 0;
}
.nav__hamburger.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* Mobile overlay menu */
.nav__mobile {
  display: none;
  position: fixed;
  inset: 0;
  background-color: var(--bg);
  z-index: 99;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.nav__mobile.is-open {
  display: flex;
}

.nav__mobile-link {
  font-size: clamp(24px, 5vw, 36px);
  font-weight: var(--weight-bold);
  color: var(--text-secondary);
  letter-spacing: -0.02em;
  padding: 8px 24px;
  transition: color var(--transition);
}

.nav__mobile-link:hover {
  color: var(--text-primary);
}

.nav__mobile-cta {
  margin-top: 24px;
  font-size: 16px;
  font-weight: var(--weight-semibold);
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 12px 32px;
  border-radius: var(--radius-sm);
}

/* =============================================================================
   6. HERO
   ============================================================================= */

.hero {
  padding-top: clamp(140px, 18vw, 200px);
  padding-bottom: var(--section-y);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse 80% 50% at 50% -10%, rgba(37, 99, 235, 0.14) 0%, transparent 70%);
  pointer-events: none;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 28px;
}

.hero__eyebrow::before {
  content: '';
  display: block;
  width: 24px;
  height: 1.5px;
  background-color: var(--accent);
}

.hero__title {
  font-size: clamp(40px, 6.5vw, 88px);
  font-weight: var(--weight-bold);
  line-height: 1.02;
  letter-spacing: -0.035em;
  max-width: 900px;
}

.hero__title em {
  font-style: normal;
  color: var(--accent);
}

.hero__sub {
  font-size: clamp(17px, 1.8vw, 21px);
  line-height: 1.65;
  color: var(--text-secondary);
  max-width: 580px;
  margin-top: 28px;
}

.hero__actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 44px;
}

/* Page hero (inner pages) */
.page-hero {
  padding-top: clamp(120px, 15vw, 180px);
  padding-bottom: clamp(48px, 6vw, 80px);
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(ellipse 60% 60% at 30% 0%, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.page-hero__title {
  max-width: 760px;
}

.page-hero__sub {
  max-width: 600px;
  margin-top: 20px;
}

/* =============================================================================
   7. BUTTONS
   ============================================================================= */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  font-weight: var(--weight-semibold);
  padding: 13px 24px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: all var(--transition);
  white-space: nowrap;
}

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

.btn--primary:hover {
  background-color: var(--accent-light);
  border-color: var(--accent-light);
}

.btn--outline {
  border-color: var(--border-light);
  color: var(--text-primary);
}

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

.btn--ghost {
  color: var(--text-secondary);
  padding-left: 0;
}

.btn--ghost:hover {
  color: var(--text-primary);
}

.btn__arrow {
  display: inline-block;
  transition: transform var(--transition);
}

.btn:hover .btn__arrow {
  transform: translateX(3px);
}

/* =============================================================================
   8. STAT / METRICS DISPLAY
   ============================================================================= */

.stats-bar {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: clamp(36px, 5vw, 60px) 0;
}

.stats-bar__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat__number {
  font-size: clamp(36px, 4.5vw, 56px);
  font-weight: var(--weight-bold);
  letter-spacing: -0.03em;
  color: var(--text-primary);
  line-height: 1;
}

.stat__number em {
  font-style: normal;
  color: var(--accent);
}

.stat__label {
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

/* =============================================================================
   9. CARDS
   ============================================================================= */

.card {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: clamp(24px, 3vw, 40px);
  transition: border-color var(--transition-md);
}

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

.card__icon {
  width: 44px;
  height: 44px;
  background-color: rgba(37, 99, 235, 0.12);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--accent);
  font-size: 20px;
}

.card__title {
  font-size: 18px;
  font-weight: var(--weight-semibold);
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.card__body {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-secondary);
}

/* Case study card */
.case-card {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-md), transform var(--transition-md);
}

.case-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.case-card__header {
  padding: 32px 36px 24px;
  border-bottom: 1px solid var(--border);
}

.case-card__sector {
  display: inline-block;
  font-size: 11px;
  font-weight: var(--weight-semibold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.case-card__title {
  font-size: clamp(18px, 2vw, 24px);
  font-weight: var(--weight-bold);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.case-card__body {
  padding: 24px 36px 32px;
}

.case-card__row {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.case-card__row:last-child {
  margin-bottom: 0;
}

.case-card__label {
  font-size: 11px;
  font-weight: var(--weight-semibold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding-top: 2px;
  flex-shrink: 0;
  width: 80px;
}

.case-card__text {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.case-card__outcome {
  color: var(--text-primary);
  font-weight: var(--weight-medium);
}

/* =============================================================================
   10. FEATURE / PROOF SECTIONS
   ============================================================================= */

.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(40px, 6vw, 80px);
  align-items: center;
}

.feature-row--reverse .feature-row__visual {
  order: -1;
}

.feature-row__visual {
  aspect-ratio: 4/3;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 13px;
  letter-spacing: 0.05em;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 28px;
}

.feature-list__item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.feature-list__dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 8px;
}

.feature-list__text {
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-secondary);
}

.section-intro {
  max-width: 620px;
  margin-bottom: clamp(40px, 5vw, 64px);
}

/* =============================================================================
   11. TRUST / TOOL BANDS
   ============================================================================= */

.trust-bar {
  padding: clamp(36px, 4vw, 56px) 0;
  border-top: 1px solid var(--border);
}

.trust-bar__label {
  text-align: center;
  margin-bottom: 32px;
}

.trust-bar__logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px 32px;
}

.trust-badge {
  display: inline-flex;
  align-items: center;
  padding: 10px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

/* =============================================================================
   12. FORMS
   ============================================================================= */

.form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form__field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form__label {
  font-size: 13px;
  font-weight: var(--weight-medium);
  color: var(--text-secondary);
  letter-spacing: 0.02em;
}

.form__input,
.form__textarea {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 15px;
  color: var(--text-primary);
  transition: border-color var(--transition);
  outline: none;
}

.form__input::placeholder,
.form__textarea::placeholder {
  color: var(--text-muted);
}

.form__input:focus,
.form__textarea:focus {
  border-color: var(--accent);
}

.form__textarea {
  min-height: 140px;
  resize: vertical;
}

.form__submit {
  align-self: flex-start;
}

/* =============================================================================
   13. DIVIDERS & DECORATIVE
   ============================================================================= */

.divider {
  width: 100%;
  height: 1px;
  background-color: var(--border);
}

.accent-rule {
  width: 40px;
  height: 2px;
  background-color: var(--accent);
  margin-bottom: 24px;
}

.number-label {
  font-size: 72px;
  font-weight: var(--weight-bold);
  letter-spacing: -0.04em;
  color: var(--text-muted);
  line-height: 1;
  margin-bottom: 16px;
}

/* =============================================================================
   14. FOOTER
   ============================================================================= */

.footer {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  padding: clamp(48px, 6vw, 80px) 0 0;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: clamp(40px, 5vw, 64px);
}

.footer__brand {
  font-size: 13px;
  font-weight: var(--weight-bold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.footer__tagline {
  font-size: 14px;
  line-height: 1.65;
  color: var(--text-secondary);
  max-width: 280px;
}

.footer__heading {
  font-size: 11px;
  font-weight: var(--weight-semibold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer__link {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color var(--transition);
}

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

.footer__bottom {
  border-top: 1px solid var(--border);
  padding: 20px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer__copy {
  font-size: 13px;
  color: var(--text-muted);
}

/* =============================================================================
   15. CTA SECTION
   ============================================================================= */

.cta-section {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: clamp(64px, 10vw, 120px) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(37, 99, 235, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

.cta-section__title {
  max-width: 640px;
  margin: 0 auto;
}

.cta-section__sub {
  max-width: 480px;
  margin: 20px auto 0;
}

.cta-section__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 40px;
}

/* =============================================================================
   16. PROCESS STEPS
   ============================================================================= */

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  position: relative;
}

.steps::before {
  content: '';
  position: absolute;
  top: 28px;
  left: calc(100% / 6);
  right: calc(100% / 6);
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border), var(--border), transparent);
  pointer-events: none;
}

.step {
  padding: clamp(24px, 3vw, 40px);
  position: relative;
}

.step__number {
  width: 56px;
  height: 56px;
  border: 1px solid var(--border-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: var(--weight-bold);
  color: var(--accent);
  margin-bottom: 24px;
  background-color: var(--bg);
  position: relative;
  z-index: 1;
}

.step__title {
  font-size: 18px;
  font-weight: var(--weight-semibold);
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.step__body {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-secondary);
}

/* =============================================================================
   17. CALENDLY PLACEHOLDER
   ============================================================================= */

.calendly-placeholder {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  min-height: 640px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  color: var(--text-muted);
  text-align: center;
  padding: 48px;
}

.calendly-placeholder__icon {
  font-size: 48px;
  margin-bottom: 8px;
}

.calendly-placeholder__title {
  font-size: 18px;
  font-weight: var(--weight-semibold);
  color: var(--text-secondary);
}

.calendly-placeholder__note {
  font-size: 13px;
  color: var(--text-muted);
  font-family: monospace;
  background-color: var(--surface-2);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

/* =============================================================================
   18. FADE-IN ANIMATION
   ============================================================================= */

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* =============================================================================
   19. RESPONSIVE
   ============================================================================= */

@media (max-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .steps::before {
    display: none;
  }

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

  .footer__grid > *:first-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .nav__links,
  .nav__cta {
    display: none;
  }

  .nav__hamburger {
    display: flex;
  }

  .grid-3,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .stats-bar__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px 16px;
  }

  .feature-row {
    grid-template-columns: 1fr;
  }

  .feature-row--reverse .feature-row__visual {
    order: 0;
  }

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

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

  .footer__grid > *:first-child {
    grid-column: auto;
  }

  .footer__bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .stats-bar__grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero__actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .cta-section__actions {
    flex-direction: column;
    align-items: stretch;
  }
}