/* ================================================================
   KnowledgeOps – Support Operations Research
   Design System & Stylesheet
   ================================================================ */

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

:root {
  /* Colors */
  --bg-primary: #F8F9FA;
  --text-primary: #0A2540;
  --text-secondary: #4A5568;
  --accent: #2FA6A0;
  --border: rgba(10, 37, 64, 0.08);
  --card-bg: #FFFFFF;
  --subtle-tint: rgba(47, 166, 160, 0.04);

  /* Typography */
  --font-base: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  /* Spacing */
  --max-width: 720px;
  --section-gap: 3.5rem;
  --element-gap: 1.5rem;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-base);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 1rem;
}

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 0.75em;
  color: var(--text-primary);
}

h1 {
  font-size: 1.625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 1.375rem;
  margin-top: 2.5rem;
}

h3 {
  font-size: 1.125rem;
  font-weight: 600;
}

p {
  margin-bottom: 1.25em;
  color: var(--text-secondary);
  font-size: 1.0625rem;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #238580;
}

ul, ol {
  margin-bottom: 1.5em;
  padding-left: 1.5em;
}

li {
  margin-bottom: 0.5em;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Header & Navigation */
header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  background: rgba(248, 249, 250, 0.95);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

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

nav {
  display: flex;
  gap: 1.75rem;
  align-items: center;
}

nav a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  position: relative;
  padding-bottom: 0.25rem;
  font-weight: 500;
}

nav a:hover {
  color: var(--text-primary);
}

nav a.active {
  color: var(--text-primary);
  font-weight: 600;
}

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

/* Main Layout */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
}

section {
  margin-bottom: var(--section-gap);
}

/* Hero Section */
.hero {
  margin-bottom: 4rem;
  position: relative;
}

.hero-label {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.hero h1 {
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.hero .subtitle {
  font-size: 1.25rem;
  line-height: 1.5;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-weight: 400;
}

.hero-content {
  display: grid;
  gap: 2.5rem;
  align-items: center;
}

.hero-visual {
  width: 100%;
  max-width: 480px;
  margin: 2rem auto 0;
}

/* CTA Buttons */
.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent);
  color: white;
  padding: 1rem 1.75rem;
  border-radius: 6px;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.2s ease;
  border: none;
  cursor: pointer;
  text-decoration: none;
  line-height: 1.4;
}

.cta:hover {
  background: #238580;
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(47, 166, 160, 0.3);
}

.cta-block {
  margin-top: 2rem;
}

.cta-reassurance {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-top: 0.875rem;
  font-style: italic;
}

/* Content Sections */
.section-title {
  font-size: 1.375rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
}

.profile-list {
  list-style: none;
  padding: 0;
}

.profile-list li {
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.75rem;
}

.profile-list li::before {
  content: '•';
  position: absolute;
  left: 0.5rem;
  color: var(--accent);
  font-weight: bold;
}

.benefits-list {
  list-style: none;
  padding: 0;
}

.benefits-list li {
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.75rem;
}

.benefits-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: bold;
}

.simple-list {
  list-style: none;
  padding: 0;
}

.simple-list li {
  padding-left: 1.5rem;
  position: relative;
  margin-bottom: 0.75rem;
}

.simple-list li::before {
  content: '–';
  position: absolute;
  left: 0.25rem;
  color: var(--text-secondary);
}

/* Founder Card */
.founder-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  margin-top: 3rem;
}

.founder-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.founder-card .title {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  font-weight: 500;
}

.founder-card p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.founder-card .contact {
  font-size: 0.9375rem;
  color: var(--accent);
  margin-top: 1.25rem;
  display: block;
  font-weight: 500;
}

/* Principles Grid */
.principles {
  display: grid;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.principle-item {
  padding: 1.25rem 1.5rem;
  background: var(--subtle-tint);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-primary);
}

/* Footer CTA Section */
.footer-cta {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2.5rem;
  margin-top: 4rem;
  text-align: left;
}

.footer-cta h2 {
  font-size: 1.375rem;
  margin-top: 0;
  margin-bottom: 1rem;
}

.footer-cta p {
  margin-bottom: 1.5rem;
}

/* Footer */
footer {
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  padding: 2.5rem 0;
  margin-top: 5rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.footer-nav {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.footer-contact {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-top: 1rem;
}

.footer-contact a {
  color: var(--accent);
  font-weight: 500;
}

.footer-copyright {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

/* Responsive Design */
@media (min-width: 768px) {
  h1 {
    font-size: 2rem;
  }

  .hero h1 {
    font-size: 2.25rem;
  }

  .hero .subtitle {
    font-size: 1.375rem;
  }

  nav {
    gap: 2rem;
  }

  .hero-content {
    grid-template-columns: 1fr 1fr;
  }

  .hero-visual {
    margin-top: 0;
  }

  .principles {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 767px) {
  .hero h1 {
    font-size: 1.625rem;
  }

  .hero .subtitle {
    font-size: 1.125rem;
  }

  nav {
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-end;
  }

  .header-inner {
    align-items: flex-start;
  }

  nav a {
    font-size: 0.875rem;
  }

  main {
    padding: 2rem 1.25rem 3rem;
  }

  .founder-card {
    padding: 1.5rem;
  }

  .footer-cta {
    padding: 2rem 1.5rem;
  }
}

/* SVG Styling */
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

.visual-accent {
  margin: 2.5rem 0;
  opacity: 0.7;
}

/* Utility Classes */
.text-secondary {
  color: var(--text-secondary);
}

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

.mt-large {
  margin-top: 3rem;
}

.mb-large {
  margin-bottom: 3rem;
}