/* ============================================
   CIVITAS Landing Page — Styles
   Design system: bochum-smartcity.de
   ============================================ */

/* --- Design Tokens --- */
:root {
  --color-primary: #0AB4FF;
  --color-primary-dark: #0093D6;
  --color-accent: #0AB4FF;
  --color-green: #66F38D;
  --color-bg: #FFFFFF;
  --color-bg-alt: #F6F6F6;
  --color-bg-code: #0d1b2a;
  --color-text: #000000;
  --color-text-body: #313131;
  --color-text-secondary: #757575;
  --color-border: #e0e0e0;
  --color-card-bg: #FFFFFF;
  --color-card-hover: #f8f9fb;

  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", Menlo, Consolas, monospace;

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.10);
  --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-card-hover: 0 8px 28px rgba(10, 180, 255, 0.18);

  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-smooth: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- 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-stack);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text-body);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* --- Layout --- */
.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-4xl) 0;
}

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

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  max-width: 640px;
  margin-bottom: var(--space-3xl);
  line-height: 1.6;
}

.tier-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-primary);
}

.tier-title--internal {
  margin-top: var(--space-3xl);
  color: var(--color-text-secondary);
  border-bottom-color: var(--color-border);
}

.card--internal {
  opacity: 0.8;
  border-style: dashed;
}

.card--internal:hover {
  opacity: 1;
  border-style: solid;
}

/* --- Header / Hero --- */
.site-header {
  background: var(--color-primary);
  padding: var(--space-3xl) 0 var(--space-3xl);
  position: relative;
  overflow: hidden;
}

.site-header::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(102, 243, 141, 0.10) 0%, transparent 70%);
  pointer-events: none;
}

.header-inner {
  position: relative;
  z-index: 1;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.header-logo-img {
  height: 48px;
  width: auto;
  flex-shrink: 0;
}

.header-title {
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  color: #000;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.header-line-img {
  display: block;
  margin-top: var(--space-lg);
  width: 231px;
  height: auto;
}

/* --- Card Grid --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition:
    box-shadow var(--transition-smooth),
    border-color var(--transition-smooth),
    transform var(--transition-smooth);
  text-decoration: none;
  color: inherit;
}

.card:hover {
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-accent);
  transform: translateY(-3px);
  color: inherit;
}

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

.card:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

.card-icon {
  width: 48px;
  height: 48px;
  margin-bottom: var(--space-md);
  flex-shrink: 0;
}

.card-icon svg {
  width: 100%;
  height: 100%;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 650;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  line-height: 1.3;
}

.card-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
  flex: 1;
  margin-bottom: var(--space-md);
}

.card-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

/* --- API Quick Start --- */
.api-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.api-card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.api-card-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
  padding: var(--space-md) var(--space-lg) 0;
}

.api-code {
  background: var(--color-bg-code);
  color: #e0e0e0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.65;
  padding: var(--space-md) var(--space-lg);
  overflow-x: auto;
  margin: var(--space-sm) 0 0;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
}

.api-code code {
  white-space: pre;
}

.api-comment {
  color: #6b7b8d;
}

.api-note {
  background: rgba(10, 180, 255, 0.06);
  border-left: 3px solid var(--color-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: var(--space-md) var(--space-lg);
  font-size: 0.9rem;
  color: var(--color-text-body);
  line-height: 1.55;
}

/* --- Repository Grid --- */
.repo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-lg);
}

.repo-card {
  display: flex;
  flex-direction: column;
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  text-decoration: none;
  color: inherit;
  transition:
    box-shadow var(--transition-smooth),
    border-color var(--transition-smooth),
    transform var(--transition-smooth);
}

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

.repo-card:hover .repo-link {
  color: var(--color-primary-dark);
}

.repo-card:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

.repo-icon {
  width: 32px;
  height: 32px;
  color: var(--color-primary-dark);
  margin-bottom: var(--space-md);
}

.repo-title {
  font-size: 1.05rem;
  font-weight: 650;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.repo-desc {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  flex: 1;
  margin-bottom: var(--space-md);
}

.repo-link {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

/* --- Footer --- */
.site-footer {
  background: var(--color-primary);
  color: var(--color-text-body);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.footer-text {
  display: flex;
  flex-direction: column;
}

.footer-text strong {
  font-size: 1rem;
  color: var(--color-text);
}

.footer-text span {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md) var(--space-xl);
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--color-text-body);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-text);
}

.footer-links a:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 2px;
  border-radius: 2px;
}

.footer-inline-link {
  color: var(--color-text-body);
}

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

.footer-copy {
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
}

/* --- FROST Detail Page --- */
.header-back {
  font-size: 0.95rem;
  color: var(--color-text);
  font-weight: 600;
  white-space: nowrap;
  flex-shrink: 0;
  margin-right: var(--space-lg);
  text-decoration: none;
}

.header-back:hover {
  color: var(--color-primary-dark);
}

.header-back:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--space-lg);
  margin-bottom: var(--space-xl);
}

.stat-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.1;
}

.stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
}

.api-endpoint {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: var(--color-bg-alt);
  padding: 2px 8px;
  border-radius: 4px;
  word-break: break-all;
}

.walkthrough-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  margin-bottom: var(--space-lg);
}

.walkthrough-title {
  font-size: 1.1rem;
  font-weight: 650;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.walkthrough-desc {
  font-size: 0.9rem;
  color: var(--color-text-body);
  line-height: 1.55;
  margin-bottom: var(--space-md);
}

.walkthrough-details {
  margin-top: var(--space-md);
}

.walkthrough-details summary {
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  padding: var(--space-sm) 0;
}

.walkthrough-details summary:hover {
  color: var(--color-primary-dark);
}

.walkthrough-meta {
  font-size: 0.78rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-sm);
  font-style: italic;
}

.walkthrough-list {
  padding-left: var(--space-xl);
  font-size: 0.9rem;
  color: var(--color-text-body);
  line-height: 2;
}

.walkthrough-list code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: var(--color-bg-alt);
  padding: 1px 5px;
  border-radius: 3px;
}

.live-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--space-md);
  margin-bottom: var(--space-md);
}

.live-item {
  background: rgba(10, 180, 255, 0.04);
  border: 1px solid rgba(10, 180, 255, 0.15);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
}

.live-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-xs);
}

.live-value {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.1;
}

.live-unit {
  display: block;
  font-size: 0.72rem;
  color: var(--color-text-secondary);
  margin-top: 2px;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .section {
    padding: var(--space-3xl) 0;
  }

  .site-header {
    padding: var(--space-3xl) 0 var(--space-2xl);
  }

  .header-brand {
    flex-direction: column;
    gap: var(--space-md);
  }

  .header-logo {
    width: 48px;
    height: 48px;
  }

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

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

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

  .footer-links {
    gap: var(--space-sm) var(--space-lg);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-md);
  }

  .section {
    padding: var(--space-2xl) 0;
  }

  .site-header {
    padding: var(--space-2xl) 0 var(--space-xl);
  }

  .section-title {
    font-size: 1.5rem;
  }

  .card {
    padding: var(--space-lg);
  }

  .api-code {
    font-size: 0.72rem;
    padding: var(--space-sm) var(--space-md);
  }

  .header-tagline {
    font-size: 1rem;
  }
}

/* --- Accessibility: Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* --- Print Styles --- */
@media print {
  .site-header {
    background: #fff;
    color: #000;
    border-bottom: 2px solid var(--color-primary);
  }

  .header-title {
    color: var(--color-primary);
  }

  .header-org,
  .header-tagline {
    color: var(--color-text-body);
  }

  .site-footer {
    background: #fff;
    color: #000;
    border-top: 2px solid var(--color-primary);
  }

  .card,
  .repo-card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ccc;
  }
}