/* ========================================
   AI Streamline Hub — Design System
   ======================================== */

/* --- CSS Variables --- */
:root {
  /* Navy palette */
  --navy-900: #0a1628;
  --navy-800: #0f2035;
  --navy-700: #152a42;
  --navy-600: #1b3550;
  --navy-500: #234568;
  --navy-400: #3a6b9f;
  --navy-300: #5a8ec4;
  --navy-200: #8bb5dc;
  --navy-100: #c4d9ed;
  --navy-50: #e8f0f8;

  /* Accent */
  --accent: #4ea8de;
  --accent-light: #7cc2e8;
  --accent-dark: #2d8bc4;

  /* Neutrals */
  --white: #ffffff;
  --gray-50: #f8f9fa;
  --gray-100: #f0f1f3;
  --gray-200: #dfe1e5;
  --gray-300: #c4c8ce;
  --gray-400: #9ca1ab;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Georgia', 'Times New Roman', serif;

  /* Spacing */
  --section-pad: 80px;
  --container-width: 1120px;
  --container-narrow: 760px;

  /* Transitions */
  --transition: 0.25s ease;
}

/* --- 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-sans);
  font-size: 17px;
  line-height: 1.7;
  color: var(--gray-700);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

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

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

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

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

.container--narrow {
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 24px;
}

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

.section--dark {
  background: var(--navy-900);
  color: var(--navy-50);
}

.section--light {
  background: var(--gray-50);
}

.section--navy {
  background: linear-gradient(135deg, var(--navy-900) 0%, var(--navy-700) 100%);
  color: var(--navy-50);
}

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

/* --- Typography --- */
h1, h2, h3, h4 {
  font-weight: 600;
  line-height: 1.25;
  color: var(--navy-900);
}

.section--dark h1, .section--dark h2, .section--dark h3,
.section--navy h1, .section--navy h2, .section--navy h3 {
  color: var(--white);
}

h1 { font-size: 2.75rem; margin-bottom: 20px; }
h2 { font-size: 2rem; margin-bottom: 16px; }
h3 { font-size: 1.35rem; margin-bottom: 12px; }
h4 { font-size: 1.1rem; margin-bottom: 8px; }

.subtitle {
  font-size: 1.2rem;
  color: var(--gray-500);
  max-width: 640px;
  margin-bottom: 40px;
}

.section--dark .subtitle, .section--navy .subtitle {
  color: var(--navy-200);
}

p + p { margin-top: 16px; }

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

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

.btn--primary:hover {
  background: var(--accent-dark);
  color: var(--white);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(78, 168, 222, 0.3);
}

.btn--outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}

.btn--outline:hover {
  background: var(--accent);
  color: var(--white);
}

.btn--white {
  background: var(--white);
  color: var(--navy-900);
}

.btn--white:hover {
  background: var(--navy-50);
  color: var(--navy-800);
  transform: translateY(-1px);
}

.btn--sm {
  padding: 10px 24px;
  font-size: 0.9rem;
}

.btn-group {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 22, 40, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: background var(--transition);
}

.nav__inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.nav__logo-text {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--white);
  letter-spacing: -0.02em;
}

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

.nav__links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav__links a {
  color: var(--navy-200);
  font-size: 0.92rem;
  font-weight: 500;
  text-decoration: none;
  transition: color var(--transition);
  position: relative;
}

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

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

.nav__cta {
  padding: 8px 20px !important;
  background: var(--accent) !important;
  color: var(--white) !important;
  border-radius: 5px !important;
  font-weight: 600 !important;
}

.nav__cta:hover {
  background: var(--accent-dark) !important;
}

/* Mobile nav toggle */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  transition: all var(--transition);
}

/* --- Hero --- */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(160deg, var(--navy-900) 0%, var(--navy-700) 60%, var(--navy-600) 100%);
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(78,168,222,0.08) 0%, transparent 70%);
}

.hero h1 {
  color: var(--white);
  font-size: 3rem;
  max-width: 720px;
  line-height: 1.2;
}

.hero .subtitle {
  font-size: 1.25rem;
  color: var(--navy-100);
  max-width: 600px;
  margin-top: 20px;
  margin-bottom: 36px;
}

/* --- Page Header (for inner pages) --- */
.page-header {
  padding: 140px 0 60px;
  background: linear-gradient(160deg, var(--navy-900) 0%, var(--navy-800) 100%);
  color: var(--white);
}

.page-header h1 {
  color: var(--white);
  font-size: 2.5rem;
}

.page-header .subtitle {
  color: var(--navy-200);
  margin-top: 12px;
}

/* --- Three Column Grid --- */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.grid-3__item h3 {
  margin-bottom: 12px;
}

.grid-3__item p {
  color: var(--gray-500);
  font-size: 0.97rem;
}

.section--dark .grid-3__item p,
.section--navy .grid-3__item p {
  color: var(--navy-200);
}

.grid-3__icon {
  width: 48px;
  height: 48px;
  background: rgba(78, 168, 222, 0.12);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--accent);
  font-size: 1.3rem;
}

/* --- Card --- */
.card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  padding: 32px;
  transition: all var(--transition);
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px rgba(78, 168, 222, 0.08);
  transform: translateY(-2px);
}

.card h3 {
  font-size: 1.15rem;
}

.card p {
  color: var(--gray-500);
  font-size: 0.95rem;
  margin-top: 8px;
}

.card__tag {
  display: inline-block;
  padding: 4px 12px;
  background: var(--navy-50);
  color: var(--navy-500);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 12px;
}

/* --- Resource Card --- */
.resource-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.resource-card h3 {
  font-size: 1.15rem;
}

.resource-card p {
  color: var(--gray-500);
  font-size: 0.95rem;
  flex-grow: 1;
}

/* --- Pillar Tag Colors --- */
.pillar--automation-gap { background: #e8f4f8; color: #1a7a8a; }
.pillar--control-illusion { background: #fef3e8; color: #b5651d; }
.pillar--how-work-happens { background: #f0e8f8; color: #6b3fa0; }
.pillar--ai-as-layer { background: #e8f8ec; color: #2d7a3e; }

/* --- Platforms Bar --- */
.platforms {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.platforms a {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--navy-200);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition);
}

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

/* --- About page --- */
.about-grid {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 48px;
  align-items: start;
}

.about-photo {
  width: 260px;
  height: 260px;
  border-radius: 12px;
  object-fit: cover;
  border: 3px solid var(--navy-100);
}

.focus-areas {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 24px;
}

.focus-area {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.95rem;
  color: var(--gray-600);
}

.focus-area::before {
  content: '→';
  color: var(--accent);
  font-weight: 600;
  flex-shrink: 0;
}

/* --- Advisory Areas --- */
.advisory-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 32px;
}

.advisory-item {
  padding: 28px;
  background: var(--gray-50);
  border-radius: 10px;
  border-left: 3px solid var(--accent);
}

.advisory-item h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.advisory-item p {
  font-size: 0.95rem;
  color: var(--gray-500);
}

/* --- Podcast Episode List --- */
.episode-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.episode {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 24px;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  transition: all var(--transition);
}

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

.episode__number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--navy-200);
  min-width: 60px;
  text-align: center;
}

.episode__info h3 {
  font-size: 1.05rem;
  margin-bottom: 4px;
}

.episode__info p {
  color: var(--gray-500);
  font-size: 0.9rem;
}

/* --- Newsletter CTA Section --- */
.newsletter-cta {
  text-align: center;
}

.newsletter-cta h2 {
  margin-bottom: 12px;
}

.newsletter-cta p {
  max-width: 560px;
  margin: 0 auto 32px;
}

/* --- Contact Form --- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.contact-info h3 {
  margin-bottom: 16px;
}

.contact-info p {
  color: var(--gray-500);
  margin-bottom: 24px;
}

.contact-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--gray-100);
  color: var(--gray-700);
  font-weight: 500;
}

.contact-link:hover {
  color: var(--accent);
}

.contact-form label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 6px;
  margin-top: 20px;
}

.contact-form label:first-child {
  margin-top: 0;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--gray-200);
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: border-color var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(78, 168, 222, 0.1);
}

.contact-form textarea {
  min-height: 140px;
  resize: vertical;
}

/* --- Footer --- */
.footer {
  background: var(--navy-900);
  color: var(--navy-300);
  padding: 60px 0 32px;
  border-top: 1px solid rgba(255,255,255,0.06);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer__brand p {
  color: var(--navy-300);
  font-size: 0.9rem;
  margin-top: 12px;
  max-width: 300px;
}

.footer h4 {
  color: var(--white);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.footer__links {
  list-style: none;
}

.footer__links li {
  margin-bottom: 10px;
}

.footer__links a {
  color: var(--navy-300);
  font-size: 0.9rem;
  transition: color var(--transition);
}

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

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

.footer__social {
  display: flex;
  gap: 20px;
}

.footer__social a {
  color: var(--navy-300);
}

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

/* --- Responsive --- */
@media (max-width: 968px) {
  .grid-3 { grid-template-columns: 1fr; gap: 28px; }
  .about-grid { grid-template-columns: 1fr; text-align: center; }
  .about-photo { margin: 0 auto; }
  .focus-areas { grid-template-columns: 1fr; }
  .advisory-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  h1 { font-size: 2.2rem; }
  .hero h1 { font-size: 2.4rem; }
}

@media (max-width: 768px) {
  :root { --section-pad: 56px; }

  .nav__links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(10, 22, 40, 0.98);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }

  .nav__links.open { display: flex; }
  .nav__toggle { display: flex; }

  .hero { padding: 120px 0 72px; }
  .hero h1 { font-size: 2rem; }
  .page-header { padding: 110px 0 48px; }
  .page-header h1 { font-size: 2rem; }

  .btn-group { flex-direction: column; align-items: flex-start; }
  .platforms { justify-content: center; }
  .footer__grid { grid-template-columns: 1fr; gap: 28px; }
  .footer__bottom { flex-direction: column; gap: 12px; text-align: center; }
  .episode { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
  body { font-size: 16px; }
  h1 { font-size: 1.8rem; }
  .hero h1 { font-size: 1.8rem; }
  .container { padding: 0 16px; }
}