/* ============================================
   TheBusinessExperts.com — Design Tokens
   ============================================ */

:root {
  /* Type Scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);

  /* Spacing (4px base) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Fonts */
  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Work Sans', 'Helvetica Neue', sans-serif;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
}

/* ============================================
   Light Mode (default)
   ============================================ */
:root, [data-theme="light"] {
  --color-bg:             #faf9f6;
  --color-surface:        #f5f3ef;
  --color-surface-2:      #efeee9;
  --color-surface-offset: #f0ede8;
  --color-divider:        #e0ddd6;
  --color-border:         #d4d0c8;

  --color-text:           #1e293b;
  --color-text-muted:     #64748b;
  --color-text-faint:     #94a3b8;
  --color-text-inverse:   #faf9f6;

  --color-primary:        #0d9488;
  --color-primary-hover:  #0a7c72;
  --color-primary-active: #07635b;
  --color-primary-highlight: #ccfbf1;

  --shadow-sm: 0 1px 2px rgba(30, 41, 59, 0.05);
  --shadow-md: 0 4px 12px rgba(30, 41, 59, 0.08);
  --shadow-lg: 0 12px 32px rgba(30, 41, 59, 0.1);
}

/* ============================================
   Dark Mode
   ============================================ */
[data-theme="dark"] {
  --color-bg:             #131820;
  --color-surface:        #1a2030;
  --color-surface-2:      #1e2638;
  --color-surface-offset: #1c2333;
  --color-divider:        #2a3344;
  --color-border:         #334155;

  --color-text:           #e2e8f0;
  --color-text-muted:     #94a3b8;
  --color-text-faint:     #64748b;
  --color-text-inverse:   #1e293b;

  --color-primary:        #2dd4bf;
  --color-primary-hover:  #5eead4;
  --color-primary-active: #14b8a6;
  --color-primary-highlight: #1a3a36;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:             #131820;
    --color-surface:        #1a2030;
    --color-surface-2:      #1e2638;
    --color-surface-offset: #1c2333;
    --color-divider:        #2a3344;
    --color-border:         #334155;
    --color-text:           #e2e8f0;
    --color-text-muted:     #94a3b8;
    --color-text-faint:     #64748b;
    --color-text-inverse:   #1e293b;
    --color-primary:        #2dd4bf;
    --color-primary-hover:  #5eead4;
    --color-primary-active: #14b8a6;
    --color-primary-highlight: #1a3a36;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.5);
  }
}

/* ============================================
   Layout
   ============================================ */
.container {
  width: 100%;
  max-width: var(--content-wide);
  margin: 0 auto;
  padding-inline: var(--space-6);
}

.container--narrow {
  max-width: var(--content-default);
}

/* ============================================
   Header
   ============================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 90%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  transition: box-shadow 0.3s ease;
}

.header--scrolled {
  box-shadow: var(--shadow-sm);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-4);
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}

.header__logo-text {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 400;
  letter-spacing: -0.01em;
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.header__nav-link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 400;
  letter-spacing: 0.01em;
}

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

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  background: transparent;
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

/* Mobile nav */
.header__mobile-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
}

@media (max-width: 768px) {
  .header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-divider);
    padding: var(--space-6);
    gap: var(--space-4);
  }

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

  .header__mobile-toggle {
    display: flex;
  }
}

/* ============================================
   Hero
   ============================================ */
.hero {
  padding-block: clamp(var(--space-20), 12vw, var(--space-32));
  text-align: center;
}

.hero__badge {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-6);
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 400;
  color: var(--color-text);
  line-height: 1.08;
  max-width: 16ch;
  margin: 0 auto var(--space-6);
  letter-spacing: -0.02em;
}

.hero__subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 52ch;
  margin: 0 auto var(--space-8);
  line-height: 1.7;
}

.hero__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
  letter-spacing: 0.01em;
}

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

.hero__cta .arrow {
  transition: transform var(--transition-interactive);
}

.hero__cta:hover .arrow {
  transform: translateX(4px);
}

/* Decorative line */
.hero__divider {
  width: 48px;
  height: 1px;
  background: var(--color-primary);
  margin: 0 auto var(--space-6);
  opacity: 0.5;
}

/* ============================================
   Section Common
   ============================================ */
.section {
  padding-block: clamp(var(--space-12), 8vw, var(--space-24));
}

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

.section__label {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
}

.section__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: var(--space-8);
  letter-spacing: -0.01em;
}

/* ============================================
   Companies Section
   ============================================ */
.companies-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
  max-width: 900px;
  margin: 0 auto;
}

@media (max-width: 640px) {
  .companies-grid {
    grid-template-columns: 1fr;
  }
}

.company-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  text-decoration: none;
  color: var(--color-text);
  transition: box-shadow var(--transition-interactive),
              border-color var(--transition-interactive),
              transform 0.3s ease;
}

.company-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.company-card__name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 400;
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

.company-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.company-card__link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-weight: 500;
}

.company-card__link .arrow {
  transition: transform var(--transition-interactive);
}

.company-card:hover .company-card__link .arrow {
  transform: translateX(4px);
}

/* ============================================
   Approach Section
   ============================================ */
.approach {
  max-width: var(--content-narrow);
  margin: 0 auto;
}

.approach__item {
  margin-bottom: var(--space-8);
}

.approach__item:last-child {
  margin-bottom: 0;
}

.approach__heading {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.approach__text {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.75;
}

/* ============================================
   Expertise Section
   ============================================ */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-1);
  max-width: 800px;
  margin: 0 auto;
}

@media (max-width: 640px) {
  .expertise-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.expertise-item {
  padding: var(--space-6);
  border-radius: var(--radius-md);
  text-align: center;
}

.expertise-item__title {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: 0.01em;
}

.expertise-item__line {
  width: 24px;
  height: 1px;
  background: var(--color-primary);
  margin: var(--space-3) auto 0;
  opacity: 0.4;
}

/* ============================================
   Insights Section
   ============================================ */
.insights-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

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

.insight-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-decoration: none;
  color: var(--color-text);
  transition: box-shadow var(--transition-interactive),
              border-color var(--transition-interactive),
              transform 0.3s ease;
}

.insight-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.insight-card__meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-bottom: var(--space-4);
}

.insight-card__meta span {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.insight-card__dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--color-text-faint);
}

.insight-card__title {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: var(--space-3);
  line-height: 1.4;
}

.insight-card__excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-12);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

.footer__top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--space-8);
}

.footer__brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  color: var(--color-text);
}

.footer__logo-text {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 400;
}

.footer__tagline {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  max-width: 36ch;
  line-height: 1.6;
}

.footer__links {
  display: flex;
  gap: var(--space-8);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
}

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

.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
}

.footer__copy {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer__attribution a {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
}

.footer__attribution a:hover {
  color: var(--color-primary);
}

/* ============================================
   Scroll Reveal Animation
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }
}