/* ===================================================================
   Bliss Science Solutions — shared site styles
   Used by: /index.html, /Articles/index.html, /Articles/*.html
   This file mirrors the design tokens of the main site exactly.
   =================================================================== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --white:      #ffffff;
  --bg:         #EBF4F9;
  --border:     rgba(30,141,184,0.15);
  --text-muted: #5B8FA8;
  --text:       #0A3A52;
  --blue:       #1179A8;
  --blue-hover: #0A3A52;
  --blue-light: rgba(17,121,168,0.07);
  --font:       'Nunito Sans', sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  font-size: 16px;
  font-weight: 400;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 15% 0%,  rgba(168,216,234,0.35) 0%, transparent 55%),
    radial-gradient(ellipse 50% 40% at 85% 90%, rgba(91,175,207,0.2)  0%, transparent 55%);
  pointer-events: none;
  z-index: 0;
}

nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(235,244,249,0.88);
  backdrop-filter: blur(18px) saturate(1.4);
  -webkit-backdrop-filter: blur(18px) saturate(1.4);
  border-bottom: 1px solid rgba(255,255,255,0.7);
  box-shadow: 0 1px 0 var(--border);
  padding: 0 2.5rem;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.nav-links { display: flex; gap: 2rem; list-style: none; }

.nav-links a {
  font-size: 14px;
  font-weight: 400;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}

.nav-links a:hover,
.nav-links a.active { color: var(--text); }

.nav-links a.active { font-weight: 600; }

.btn {
  font-family: var(--font);
  font-size: 14px;
  font-weight: 600;
  padding: 11px 24px;
  border-radius: 4px;
  text-decoration: none;
  display: inline-block;
  transition: all 0.15s;
  cursor: pointer;
  border: none;
}

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

.btn-secondary {
  background: rgba(255,255,255,0.55);
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.7);
  backdrop-filter: blur(8px);
}
.btn-secondary:hover { background: rgba(255,255,255,0.85); }

/* ---------- shared page chrome: hero / section / footer ---------- */

.hero {
  position: relative;
  z-index: 1;
  padding: 5rem 2.5rem 4rem;
  max-width: 760px;
  margin-left: max(2.5rem, calc(50vw - 480px));
}

.hero .section-label { margin-bottom: 0.6rem; }

.hero h1 {
  font-size: clamp(1.9rem, 3.5vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.hero p {
  font-size: 17px;
  line-height: 1.75;
  color: var(--text-muted);
  font-weight: 300;
  max-width: 560px;
}

.section-container {
  max-width: 960px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
  padding: 0 2.5rem;
}

.section-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 0.4rem;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 2rem;
}

footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--border);
  padding: 1.5rem 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(235,244,249,0.7);
  backdrop-filter: blur(12px);
  margin-top: 4rem;
}

.footer-left { font-size: 14px; font-weight: 700; color: var(--text); }
.footer-right { font-size: 13px; color: var(--text-muted); }

.footer-links { display: flex; gap: 1.5rem; list-style: none; }

.footer-links a {
  font-size: 13px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
.footer-links a:hover { color: var(--text); }

/* ---------- article index: card grid ---------- */

.articles-section { padding: 1rem 0 5rem; }

.articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.article-card {
  background: rgba(255,255,255,0.55);
  backdrop-filter: blur(16px) saturate(1.3);
  -webkit-backdrop-filter: blur(16px) saturate(1.3);
  border: 1px solid rgba(255,255,255,0.75);
  box-shadow: 0 2px 20px rgba(17,121,168,0.07), inset 0 1px 0 rgba(255,255,255,0.9);
  border-radius: 6px;
  padding: 1.75rem;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: transform 0.15s, box-shadow 0.15s;
}

.article-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(17,121,168,0.13), inset 0 1px 0 rgba(255,255,255,0.9);
}

.article-card-meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.article-tag {
  color: var(--blue);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.article-dot { color: var(--border); }

.article-date,
.article-readtime { color: var(--text-muted); font-weight: 400; }

.article-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
  line-height: 1.4;
}

.article-card p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
  font-weight: 300;
}

.article-card-arrow {
  margin-top: auto;
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
}

.articles-empty {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 300;
  padding: 2rem 0;
}

/* ---------- single article page ---------- */

.article-hero {
  position: relative;
  z-index: 1;
  padding: 3.5rem 2.5rem 2.5rem;
  max-width: 720px;
  margin: 0 auto;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
  text-decoration: none;
  margin-bottom: 1.5rem;
}
.back-link:hover { color: var(--blue-hover); }

.article-hero h1 {
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text);
  letter-spacing: -0.02em;
  margin: 0.75rem 0 1rem;
}

.article-hero .article-card-meta { margin-bottom: 0; }

.article-wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 2.5rem 4rem;
  position: relative;
  z-index: 1;
}

.article-body {
  background: rgba(255,255,255,0.55);
  backdrop-filter: blur(16px) saturate(1.3);
  -webkit-backdrop-filter: blur(16px) saturate(1.3);
  border: 1px solid rgba(255,255,255,0.75);
  box-shadow: 0 2px 20px rgba(17,121,168,0.07), inset 0 1px 0 rgba(255,255,255,0.9);
  border-radius: 6px;
  padding: 2.5rem;
}

.article-body p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-muted);
  font-weight: 300;
  margin-bottom: 1.1rem;
}

.article-body h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
  margin: 1.75rem 0 0.75rem;
}

.article-body h2:first-child { margin-top: 0; }

.article-body ul,
.article-body ol {
  margin: 0 0 1.1rem 1.25rem;
  color: var(--text-muted);
  font-size: 15px;
  font-weight: 300;
  line-height: 1.8;
}

.article-body li { margin-bottom: 0.35rem; }

.article-body strong { color: var(--text); font-weight: 600; }

.article-body blockquote {
  border-left: 3px solid var(--blue);
  padding: 0.25rem 0 0.25rem 1.25rem;
  margin: 1.25rem 0;
  color: var(--text);
  font-weight: 400;
  font-style: italic;
}

.article-cta {
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.article-cta p { font-size: 14px; color: var(--text-muted); font-weight: 300; margin: 0; }

@media (max-width: 640px) {
  nav { padding: 0 1.25rem; height: 54px; }
  .nav-links { display: none; }

  .hero { padding: 3rem 1.25rem 2.5rem; margin-left: 0; max-width: 100%; }
  .hero h1 { font-size: 1.75rem; }
  .hero p { font-size: 15px; }

  .section-container { padding: 0 1.25rem; }
  .articles-grid { grid-template-columns: 1fr; }

  .article-hero { padding: 2rem 1.25rem 1.5rem; }
  .article-wrap { padding: 0 1.25rem 3rem; }
  .article-body { padding: 1.5rem; }

  footer { flex-direction: column; gap: 0.75rem; text-align: center; padding: 1.25rem; }
  .footer-links { justify-content: center; }
}