/* =============================================
   Evolving Orgs — Main Stylesheet
   ============================================= */

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

:root {
  --color-bg: #fafaf8;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #6b6b6b;
  --color-accent: #2d5be3;
  --color-accent-hover: #1e45c8;
  --color-border: #e5e5e2;
  --color-rule: #d4d4d0;

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

  --size-xs: 0.75rem;
  --size-sm: 0.875rem;
  --size-base: 1rem;
  --size-lg: 1.125rem;
  --size-xl: 1.25rem;
  --size-2xl: 1.5rem;
  --size-3xl: 1.875rem;
  --size-4xl: 2.25rem;
  --size-5xl: 3rem;

  --max-width: 720px;
  --max-width-wide: 1080px;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--size-base);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  line-height: 1.2;
  font-weight: 600;
  letter-spacing: -0.01em;
}

h1 { font-size: var(--size-4xl); }
h2 { font-size: var(--size-3xl); }
h3 { font-size: var(--size-xl); }
h4 { font-size: var(--size-lg); }

p { margin-bottom: var(--space-4); }
p:last-child { margin-bottom: 0; }

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

strong { font-weight: 600; }

ul, ol {
  padding-left: var(--space-6);
  margin-bottom: var(--space-4);
}
li { margin-bottom: var(--space-2); }

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container--wide {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section {
  padding: var(--space-20) 0;
}

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

.section--dark {
  background-color: var(--color-text);
  color: #f0efeb;
}

hr.rule {
  border: none;
  border-top: 1px solid var(--color-rule);
  margin: var(--space-12) 0;
}

/* --- Nav --- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-4) 0;
}

.site-nav__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
}

.site-nav__brand {
  font-weight: 700;
  font-size: var(--size-base);
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.site-nav__brand:hover { text-decoration: none; }

.site-nav__links {
  display: flex;
  gap: var(--space-6);
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-nav__links a {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.15s;
}
.site-nav__links a:hover,
.site-nav__links a[aria-current="page"] {
  color: var(--color-text);
}

.site-nav__cta {
  font-size: var(--size-sm);
  font-weight: 600;
  color: var(--color-accent) !important;
}
.site-nav__cta:hover { color: var(--color-accent-hover) !important; }

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) 0;
  margin-top: var(--space-24);
}

.site-footer__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.site-footer__brand {
  font-weight: 700;
  font-size: var(--size-sm);
  color: var(--color-text);
  text-decoration: none;
}

.site-footer__links {
  display: flex;
  gap: var(--space-6);
  list-style: none;
  padding: 0;
  margin: 0;
}
.site-footer__links a {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  text-decoration: none;
}
.site-footer__links a:hover { color: var(--color-text); }

.site-footer__copy {
  font-size: var(--size-xs);
  color: var(--color-text-muted);
  width: 100%;
  margin-top: var(--space-4);
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 0.65rem 1.35rem;
  border-radius: 4px;
  font-size: var(--size-sm);
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s, color 0.15s, border-color 0.15s;
  text-decoration: none;
  border: 1.5px solid transparent;
  line-height: 1.4;
}

.btn--primary {
  background-color: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn--primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  text-decoration: none;
  color: #fff;
}

.btn--outline {
  background-color: transparent;
  color: var(--color-text);
  border-color: var(--color-text);
}
.btn--outline:hover {
  background-color: var(--color-text);
  color: var(--color-bg);
  text-decoration: none;
}

.btn--outline-light {
  background-color: transparent;
  color: #f0efeb;
  border-color: rgba(240,239,235,0.5);
}
.btn--outline-light:hover {
  background-color: rgba(240,239,235,0.1);
  text-decoration: none;
  color: #fff;
}

/* --- Hero --- */
.hero {
  padding: var(--space-24) 0 var(--space-20);
  border-bottom: 1px solid var(--color-border);
}

.hero__eyebrow {
  font-size: var(--size-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

.hero__headline {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: var(--space-6);
  max-width: 640px;
}

.hero__sub {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  max-width: 520px;
  margin-bottom: var(--space-8);
  line-height: 1.6;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* --- Prose sections --- */
.prose-section__label {
  font-size: var(--size-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.prose-section__heading {
  font-size: var(--size-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-6);
  max-width: 580px;
}

.prose-section__body {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  max-width: 580px;
  line-height: 1.7;
}

/* --- Article cards --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.card__label {
  font-size: var(--size-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.card__title {
  font-size: var(--size-lg);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.3;
  color: var(--color-text);
}

.card__body {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  flex: 1;
}

.card__link {
  font-size: var(--size-sm);
  font-weight: 600;
  color: var(--color-accent);
  text-decoration: none;
}
.card__link:hover { text-decoration: underline; }

/* --- Services grid --- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.service-item {
  border-top: 2px solid var(--color-accent);
  padding-top: var(--space-4);
}

.service-item__title {
  font-size: var(--size-base);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.service-item__body {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* --- Email signup --- */
.signup-section {
  background-color: var(--color-text);
  color: #f0efeb;
  padding: var(--space-20) 0;
}

.signup-section .container {
  text-align: center;
}

.signup-section__heading {
  font-size: var(--size-3xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
  color: #fff;
}

.signup-section__sub {
  font-size: var(--size-lg);
  color: rgba(240,239,235,0.7);
  margin-bottom: var(--space-8);
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.signup-form {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
  max-width: 480px;
  margin: 0 auto;
}

.signup-form input[type="text"],
.signup-form input[type="email"] {
  flex: 1;
  min-width: 180px;
  padding: 0.65rem 0.875rem;
  border: 1.5px solid rgba(240,239,235,0.25);
  border-radius: 4px;
  background: rgba(255,255,255,0.06);
  color: #f0efeb;
  font-size: var(--size-sm);
  font-family: var(--font-sans);
  outline: none;
  transition: border-color 0.15s;
}
.signup-form input::placeholder { color: rgba(240,239,235,0.4); }
.signup-form input:focus { border-color: rgba(240,239,235,0.6); }

.signup-form button {
  padding: 0.65rem 1.35rem;
  border-radius: 4px;
  background-color: var(--color-accent);
  color: #fff;
  border: none;
  font-size: var(--size-sm);
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font-sans);
  transition: background-color 0.15s;
}
.signup-form button:hover { background-color: var(--color-accent-hover); }

.signup-note {
  font-size: var(--size-xs);
  color: rgba(240,239,235,0.45);
  margin-top: var(--space-3);
}

/* --- Briefing block --- */
.briefing-block {
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: var(--space-8);
  margin-top: var(--space-8);
  background: var(--color-surface);
}

.briefing-block__eyebrow {
  font-size: var(--size-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

.briefing-block__title {
  font-size: var(--size-2xl);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-4);
}

.briefing-block__body {
  font-size: var(--size-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
  max-width: 520px;
}

.briefing-block__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}

.briefing-block__meta-item {
  font-size: var(--size-sm);
}
.briefing-block__meta-item strong {
  display: block;
  color: var(--color-text);
}
.briefing-block__meta-item span {
  color: var(--color-text-muted);
}

/* --- Diagram --- */
.diagram-wrap {
  margin: var(--space-8) 0;
  overflow-x: auto;
}

/* --- Page header --- */
.page-header {
  padding: var(--space-16) 0 var(--space-12);
  border-bottom: 1px solid var(--color-border);
}

.page-header__label {
  font-size: var(--size-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
}

.page-header__title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

.page-header__sub {
  font-size: var(--size-lg);
  color: var(--color-text-muted);
  max-width: 540px;
  line-height: 1.6;
}

/* --- Article list --- */
.article-list {
  list-style: none;
  padding: 0;
  margin: var(--space-8) 0 0;
}

.article-list__item {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-4);
  align-items: start;
}

.article-list__item:last-child {
  border-bottom: 1px solid var(--color-border);
}

.article-list__title {
  font-size: var(--size-xl);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-2);
  line-height: 1.3;
}

.article-list__title a {
  color: var(--color-text);
  text-decoration: none;
}
.article-list__title a:hover { color: var(--color-accent); text-decoration: none; }

.article-list__desc {
  font-size: var(--size-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.article-list__date {
  font-size: var(--size-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
  padding-top: 4px;
}

/* --- Article prose --- */
.article-prose {
  font-size: var(--size-lg);
  line-height: 1.75;
  max-width: 660px;
}

.article-prose h2 {
  font-size: var(--size-2xl);
  margin-top: var(--space-12);
  margin-bottom: var(--space-4);
}

.article-prose h3 {
  font-size: var(--size-xl);
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
}

.article-prose p {
  margin-bottom: var(--space-6);
}

.article-prose ul,
.article-prose ol {
  margin-bottom: var(--space-6);
}

.article-prose li {
  margin-bottom: var(--space-3);
}

.article-prose blockquote {
  border-left: 3px solid var(--color-accent);
  padding-left: var(--space-6);
  margin: var(--space-8) 0;
  color: var(--color-text-muted);
  font-style: italic;
}

/* --- Contact form --- */
.contact-form {
  max-width: 540px;
  margin-top: var(--space-8);
}

.form-group {
  margin-bottom: var(--space-6);
}

.form-group label {
  display: block;
  font-size: var(--size-sm);
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.65rem 0.875rem;
  border: 1.5px solid var(--color-border);
  border-radius: 4px;
  font-size: var(--size-base);
  font-family: var(--font-sans);
  background: var(--color-surface);
  color: var(--color-text);
  outline: none;
  transition: border-color 0.15s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-accent);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* --- Mobile nav toggle --- */
.site-nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.site-nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}

/* --- Responsive --- */
@media (max-width: 640px) {
  h1 { font-size: var(--size-3xl); }
  h2 { font-size: var(--size-2xl); }

  .hero { padding: var(--space-16) 0 var(--space-12); }

  /* Mobile nav */
  .site-nav__toggle { display: flex; }

  .site-nav__links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--space-4) var(--space-6);
    gap: var(--space-4);
    z-index: 99;
  }
  .site-nav__links.is-open { display: flex; }
  .site-nav__links a { font-size: var(--size-base); }

  .site-nav { position: relative; }

  /* Diagram scrolls horizontally */
  .diagram-wrap {
    -webkit-overflow-scrolling: touch;
  }

  .article-list__item {
    grid-template-columns: 1fr;
  }

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

  .briefing-block { padding: var(--space-6); }

  .briefing-block__meta { flex-direction: column; gap: var(--space-4); }

  .section { padding: var(--space-12) 0; }
}

@media (max-width: 480px) {
  .hero__headline { font-size: 1.75rem; }
  .hero__actions { flex-direction: column; }
  .hero__actions .btn { text-align: center; }
  .signup-form { flex-direction: column; }
  .signup-form input, .signup-form button { width: 100%; }
}