/* IBM Carbon Design System — SaaS Chatbots */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400&family=IBM+Plex+Sans:wght@300;400;600&display=swap');

/* ─── Carbon Tokens ─── */
:root {
  --cds-background: #ffffff;
  --cds-layer-01: #f4f4f4;
  --cds-layer-02: #e0e0e0;
  --cds-layer-hover: #e8e8e8;
  --cds-text-primary: #161616;
  --cds-text-secondary: #525252;
  --cds-text-placeholder: #6f6f6f;
  --cds-text-disabled: #8d8d8d;
  --cds-border-subtle: #c6c6c6;
  --cds-border-strong: #8d8d8d;
  --cds-button-primary: #0f62fe;
  --cds-button-primary-hover: #0353e9;
  --cds-button-primary-active: #002d9c;
  --cds-link-primary: #0f62fe;
  --cds-link-primary-hover: #0043ce;
  --cds-focus: #0f62fe;
  --cds-support-error: #da1e28;
  --cds-support-success: #24a148;
  --cds-support-warning: #f1c21b;
  --cds-nav-bg: #161616;
  --cds-nav-text: #c6c6c6;
  --cds-nav-text-hover: #ffffff;
  --cds-tag-blue-bg: #edf5ff;
  --cds-tag-blue-text: #0f62fe;
  --space-2: 2px;
  --space-4: 4px;
  --space-8: 8px;
  --space-12: 12px;
  --space-16: 16px;
  --space-24: 24px;
  --space-32: 32px;
  --space-40: 40px;
  --space-48: 48px;
  --space-64: 64px;
  --space-80: 80px;
  --space-96: 96px;
  --space-160: 160px;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'IBM Plex Sans', 'Helvetica Neue', Arial, sans-serif;
  font-weight: 400;
  color: var(--cds-text-primary);
  background: var(--cds-background);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--cds-link-primary);
  text-decoration: none;
}
a:hover {
  color: var(--cds-link-primary-hover);
  text-decoration: underline;
}

/* ─── Container / Grid ─── */
.container {
  width: 100%;
  max-width: 1584px;
  margin: 0 auto;
  padding: 0 var(--space-16);
}
@media (min-width: 672px) { .container { padding: 0 var(--space-32); } }

/* ─── Navigation ─── */
.site-nav {
  background: var(--cds-nav-bg);
  height: var(--space-48);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid #262626;
}
.site-nav .container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  text-decoration: none;
}
.nav-brand-icon {
  width: 20px;
  height: 20px;
  background: var(--cds-button-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.nav-brand-icon svg { display: block; }
.nav-brand-text {
  font-size: 14px;
  font-weight: 600;
  color: #ffffff;
  letter-spacing: 0.16px;
}
.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 0;
  height: 100%;
}
.nav-links li { height: 100%; }
.nav-links a {
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 var(--space-16);
  font-size: 14px;
  font-weight: 400;
  color: var(--cds-nav-text);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.1s, border-color 0.1s;
  letter-spacing: 0.16px;
}
.nav-links a:hover { color: var(--cds-nav-text-hover); text-decoration: none; }
.nav-links a.active { color: #ffffff; border-bottom-color: var(--cds-button-primary); }
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-8);
}
.nav-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: #ffffff;
  margin: 4px 0;
  transition: 0.2s;
}
@media (max-width: 671px) {
  .nav-links { display: none; }
  .nav-hamburger { display: block; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--space-48);
    left: 0;
    right: 0;
    background: var(--cds-nav-bg);
    height: auto;
    border-top: 1px solid #262626;
  }
  .nav-links.open li { width: 100%; height: var(--space-48); }
  .nav-links.open a { border-bottom: 1px solid #262626; padding: 0 var(--space-16); }
}

/* ─── Hero ─── */
.hero {
  background: var(--cds-background);
  padding: var(--space-80) 0 var(--space-64);
  border-bottom: 1px solid var(--cds-layer-02);
}
.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-48);
}
.hero-eyebrow {
  font-size: 12px;
  font-weight: 400;
  color: var(--cds-button-primary);
  letter-spacing: 0.32px;
  text-transform: uppercase;
  margin-bottom: var(--space-16);
}
.hero-headline {
  font-size: clamp(2rem, 5vw, 3.75rem);
  font-weight: 300;
  line-height: 1.17;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-24);
  max-width: 800px;
}
.hero-subhead {
  font-size: 16px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--cds-text-secondary);
  max-width: 640px;
  margin-bottom: var(--space-40);
}
.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-16);
  align-items: center;
}
.hero-stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2);
  background: var(--cds-layer-02);
  width: 100%;
  max-width: 640px;
}
.hero-stat {
  background: var(--cds-layer-01);
  padding: var(--space-32) var(--space-24);
}
.hero-stat-number {
  font-family: 'IBM Plex Mono', Menlo, monospace;
  font-size: 2.63rem;
  font-weight: 400;
  color: var(--cds-text-primary);
  line-height: 1.19;
  margin-bottom: var(--space-8);
}
.hero-stat-label {
  font-size: 12px;
  font-weight: 400;
  color: var(--cds-text-secondary);
  letter-spacing: 0.32px;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-8);
  height: var(--space-48);
  padding: 0 63px 0 15px;
  font-family: 'IBM Plex Sans', sans-serif;
  font-size: 14px;
  font-weight: 400;
  letter-spacing: 0.16px;
  border: 1px solid transparent;
  border-radius: 0;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.1s;
  white-space: nowrap;
  position: relative;
}
.btn-primary {
  background: var(--cds-button-primary);
  color: #ffffff;
}
.btn-primary:hover {
  background: var(--cds-button-primary-hover);
  color: #ffffff;
  text-decoration: none;
}
.btn-primary:active { background: var(--cds-button-primary-active); }
.btn-secondary {
  background: #393939;
  color: #ffffff;
  padding: 0 48px 0 15px;
}
.btn-secondary:hover { background: #4c4c4c; color: #ffffff; text-decoration: none; }
.btn-ghost {
  background: transparent;
  color: var(--cds-button-primary);
  border-color: var(--cds-button-primary);
  padding: 0 15px;
}
.btn-ghost:hover { background: var(--cds-tag-blue-bg); color: var(--cds-button-primary); text-decoration: none; }
.btn-sm { height: var(--space-40); font-size: 14px; padding: 0 40px 0 15px; }
.btn svg { flex-shrink: 0; }

/* ─── Feature Section ─── */
.section {
  padding: var(--space-64) 0;
}
.section-alt { background: var(--cds-layer-01); }
.section-dark {
  background: var(--cds-nav-bg);
  color: #ffffff;
}
.section-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.32px;
  text-transform: uppercase;
  color: var(--cds-button-primary);
  margin-bottom: var(--space-16);
}
.section-dark .section-label { color: #78a9ff; }
.section-headline {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 300;
  line-height: 1.25;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-16);
  max-width: 720px;
}
.section-dark .section-headline { color: #f4f4f4; }
.section-subhead {
  font-size: 16px;
  line-height: 1.5;
  color: var(--cds-text-secondary);
  max-width: 600px;
  margin-bottom: var(--space-48);
}
.section-dark .section-subhead { color: #c6c6c6; }

/* ─── Card Grid ─── */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  background: var(--cds-layer-02);
}
@media (min-width: 672px) { .card-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1056px) { .card-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1312px) { .card-grid.grid-4 { grid-template-columns: repeat(4, 1fr); } }

.card {
  background: var(--cds-background);
  padding: var(--space-32) var(--space-24);
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
  border-bottom: 4px solid transparent;
  transition: background 0.1s, border-color 0.1s;
  text-decoration: none;
  color: inherit;
}
.section-alt .card { background: var(--cds-layer-01); }
.card:hover { background: var(--cds-layer-hover); border-bottom-color: var(--cds-button-primary); text-decoration: none; color: inherit; }
.card-icon {
  width: 32px;
  height: 32px;
  background: var(--cds-tag-blue-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-8);
  flex-shrink: 0;
}
.card-icon svg { color: var(--cds-button-primary); }
.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--cds-text-primary);
}
.card-body {
  font-size: 14px;
  font-weight: 400;
  line-height: 1.29;
  letter-spacing: 0.16px;
  color: var(--cds-text-secondary);
  flex: 1;
}
.card-arrow {
  align-self: flex-end;
  color: var(--cds-button-primary);
  margin-top: auto;
}

/* ─── Blog Post Card ─── */
.post-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  background: var(--cds-layer-02);
}
@media (min-width: 672px) { .post-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1056px) { .post-grid { grid-template-columns: repeat(3, 1fr); } }

.post-card {
  background: var(--cds-background);
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  transition: background 0.1s;
  border-bottom: 4px solid transparent;
}
.post-card:hover { background: var(--cds-layer-hover); border-bottom-color: var(--cds-button-primary); text-decoration: none; color: inherit; }
.post-card-meta {
  padding: var(--space-24) var(--space-24) var(--space-16);
  border-bottom: 1px solid var(--cds-layer-02);
  display: flex;
  align-items: center;
  gap: var(--space-8);
}
.post-card-category {
  font-size: 12px;
  font-weight: 400;
  color: var(--cds-button-primary);
  letter-spacing: 0.32px;
  text-transform: uppercase;
}
.post-card-date {
  font-size: 12px;
  color: var(--cds-text-secondary);
  letter-spacing: 0.32px;
  margin-left: auto;
}
.post-card-content {
  padding: var(--space-24);
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
}
.post-card-title {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--cds-text-primary);
}
.post-card-summary {
  font-size: 14px;
  line-height: 1.29;
  letter-spacing: 0.16px;
  color: var(--cds-text-secondary);
  flex: 1;
}
.post-card-footer {
  padding: var(--space-16) var(--space-24);
  border-top: 1px solid var(--cds-layer-02);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.post-card-read {
  font-size: 14px;
  font-weight: 600;
  color: var(--cds-button-primary);
  letter-spacing: 0.16px;
}
.post-card-time {
  font-size: 12px;
  color: var(--cds-text-secondary);
}

/* ─── Tags ─── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--space-4) var(--space-8);
  border-radius: 24px;
  font-size: 12px;
  font-weight: 400;
  background: var(--cds-tag-blue-bg);
  color: var(--cds-tag-blue-text);
  text-decoration: none;
}
.tag:hover { background: #d0e2ff; color: var(--cds-button-primary); text-decoration: none; }
.tag-list { display: flex; flex-wrap: wrap; gap: var(--space-8); }

/* ─── CTA Banner ─── */
.cta-banner {
  background: var(--cds-nav-bg);
  padding: var(--space-64) 0;
}
.cta-banner-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-32);
}
@media (min-width: 1056px) {
  .cta-banner-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}
.cta-banner-text h2 {
  font-size: clamp(1.5rem, 3vw, 2.63rem);
  font-weight: 300;
  line-height: 1.19;
  color: #f4f4f4;
  margin-bottom: var(--space-16);
}
.cta-banner-text p {
  font-size: 16px;
  line-height: 1.5;
  color: #c6c6c6;
  max-width: 560px;
}
.cta-banner-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-16);
  flex-shrink: 0;
}

/* ─── Article / Single Post ─── */
.article-header {
  background: var(--cds-background);
  padding: var(--space-64) 0 var(--space-48);
  border-bottom: 1px solid var(--cds-layer-02);
}
.article-breadcrumb {
  font-size: 12px;
  color: var(--cds-text-secondary);
  letter-spacing: 0.32px;
  margin-bottom: var(--space-24);
  display: flex;
  align-items: center;
  gap: var(--space-8);
}
.article-breadcrumb a { color: var(--cds-button-primary); text-decoration: none; }
.article-category {
  font-size: 12px;
  font-weight: 400;
  color: var(--cds-button-primary);
  letter-spacing: 0.32px;
  text-transform: uppercase;
  margin-bottom: var(--space-16);
}
.article-title {
  font-size: clamp(2rem, 4vw, 2.63rem);
  font-weight: 300;
  line-height: 1.19;
  color: var(--cds-text-primary);
  max-width: 800px;
  margin-bottom: var(--space-24);
}
.article-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-16);
  font-size: 12px;
  color: var(--cds-text-secondary);
  letter-spacing: 0.32px;
}
.article-meta-dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--cds-border-subtle);
}
.article-body {
  padding: var(--space-64) 0;
}
.article-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-64);
}
@media (min-width: 1056px) {
  .article-layout { grid-template-columns: 1fr 320px; }
}
.article-content {
  max-width: 720px;
}
.article-content h2 {
  font-size: 1.5rem;
  font-weight: 400;
  line-height: 1.33;
  color: var(--cds-text-primary);
  margin: var(--space-48) 0 var(--space-16);
}
.article-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--cds-text-primary);
  margin: var(--space-32) 0 var(--space-12);
}
.article-content p {
  font-size: 16px;
  line-height: 1.5;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-24);
}
.article-content ul, .article-content ol {
  padding-left: var(--space-24);
  margin-bottom: var(--space-24);
}
.article-content li {
  font-size: 16px;
  line-height: 1.5;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-8);
}
.article-content strong { font-weight: 600; }
.article-content code {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.88rem;
  letter-spacing: 0.16px;
  background: var(--cds-layer-01);
  padding: 2px 6px;
  color: var(--cds-text-primary);
}
.article-content pre {
  background: var(--cds-nav-bg);
  padding: var(--space-24);
  margin-bottom: var(--space-24);
  overflow-x: auto;
}
.article-content pre code {
  background: none;
  color: #f4f4f4;
  padding: 0;
  font-size: 0.88rem;
  letter-spacing: 0.16px;
  line-height: 1.43;
}
.article-content blockquote {
  border-left: 4px solid var(--cds-button-primary);
  padding: var(--space-16) var(--space-24);
  margin: var(--space-32) 0;
  background: var(--cds-layer-01);
}
.article-content blockquote p {
  font-size: 1.25rem;
  font-weight: 300;
  line-height: 1.4;
  color: var(--cds-text-primary);
  margin: 0;
}

/* ─── Sidebar ─── */
.sidebar {}
.sidebar-widget {
  background: var(--cds-layer-01);
  padding: var(--space-24);
  margin-bottom: var(--space-2);
}
.sidebar-widget-title {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.16px;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-16);
  padding-bottom: var(--space-12);
  border-bottom: 2px solid var(--cds-button-primary);
}
.sidebar-link-list { list-style: none; }
.sidebar-link-list li {
  padding: var(--space-8) 0;
  border-bottom: 1px solid var(--cds-layer-02);
  font-size: 14px;
  letter-spacing: 0.16px;
}
.sidebar-link-list li:last-child { border-bottom: none; }
.sidebar-link-list a { color: var(--cds-text-primary); text-decoration: none; }
.sidebar-link-list a:hover { color: var(--cds-link-primary); }

/* ─── Newsletter Widget ─── */
.newsletter-widget {
  background: var(--cds-nav-bg);
  padding: var(--space-24);
}
.newsletter-widget .sidebar-widget-title { color: #f4f4f4; border-color: var(--cds-button-primary); }
.newsletter-widget p { font-size: 14px; color: #c6c6c6; line-height: 1.29; margin-bottom: var(--space-16); letter-spacing: 0.16px; }
.newsletter-input {
  width: 100%;
  background: #262626;
  border: none;
  border-bottom: 2px solid #525252;
  color: #f4f4f4;
  font-family: 'IBM Plex Sans', sans-serif;
  font-size: 14px;
  height: var(--space-40);
  padding: 0 var(--space-16);
  outline: none;
  margin-bottom: var(--space-8);
  display: block;
  letter-spacing: 0.16px;
}
.newsletter-input:focus { border-bottom-color: var(--cds-focus); }
.newsletter-input::placeholder { color: #6f6f6f; }
.newsletter-btn {
  width: 100%;
  justify-content: center;
  padding: 0 var(--space-16);
}

/* ─── List / Blog Index ─── */
.page-header {
  background: var(--cds-background);
  padding: var(--space-64) 0 var(--space-48);
  border-bottom: 1px solid var(--cds-layer-02);
}
.page-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 300;
  line-height: 1.17;
  color: var(--cds-text-primary);
  margin-bottom: var(--space-16);
}
.page-desc {
  font-size: 16px;
  line-height: 1.5;
  color: var(--cds-text-secondary);
  max-width: 640px;
}

/* ─── Pagination ─── */
.pagination {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-48) 0;
}
.pagination a, .pagination span {
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--space-40);
  min-width: var(--space-40);
  padding: 0 var(--space-16);
  font-size: 14px;
  letter-spacing: 0.16px;
  background: var(--cds-layer-01);
  color: var(--cds-text-primary);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: background 0.1s, border-color 0.1s;
}
.pagination a:hover { background: var(--cds-layer-hover); text-decoration: none; }
.pagination .current { background: var(--cds-button-primary); color: #ffffff; }

/* ─── Footer ─── */
.site-footer {
  background: var(--cds-nav-bg);
  color: #c6c6c6;
  padding: var(--space-64) 0 var(--space-32);
  border-top: 1px solid #262626;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-48);
  margin-bottom: var(--space-48);
}
@media (min-width: 672px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 1056px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; } }
.footer-brand p {
  font-size: 14px;
  line-height: 1.29;
  letter-spacing: 0.16px;
  color: #8d8d8d;
  margin-top: var(--space-16);
  max-width: 280px;
}
.footer-col-title {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.32px;
  text-transform: uppercase;
  color: #f4f4f4;
  margin-bottom: var(--space-16);
}
.footer-links { list-style: none; }
.footer-links li { margin-bottom: var(--space-8); }
.footer-links a {
  font-size: 14px;
  letter-spacing: 0.16px;
  color: #c6c6c6;
  text-decoration: none;
}
.footer-links a:hover { color: #ffffff; text-decoration: none; }
.footer-bottom {
  border-top: 1px solid #262626;
  padding-top: var(--space-24);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-16);
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  letter-spacing: 0.32px;
  color: #8d8d8d;
}
.footer-bottom a { color: #8d8d8d; }
.footer-bottom a:hover { color: #c6c6c6; }

/* ─── Utility ─── */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
}
.divider {
  border: none;
  border-top: 1px solid var(--cds-layer-02);
  margin: var(--space-48) 0;
}
.text-center { text-align: center; }
.mt-16 { margin-top: var(--space-16); }
.mt-32 { margin-top: var(--space-32); }
.mt-48 { margin-top: var(--space-48); }
.mb-16 { margin-bottom: var(--space-16); }
.mb-32 { margin-bottom: var(--space-32); }
.flex-center { display: flex; justify-content: center; }