@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

:root {
  --brand-bg: #0b1623;
  --brand-bg-alt: #101f32;
  --brand-surface: #15283f;
  --brand-surface-soft: rgba(21, 40, 63, 0.65);
  --brand-border: rgba(116, 142, 168, 0.18);
  --brand-text: #f3f7fc;
  --brand-text-soft: #a7b7c9;
  --brand-accent: #3db7ff;
  --brand-accent-strong: #00c0a3;
  --brand-gradient: linear-gradient(135deg, #3db7ff, #8f7bff 45%, #ff6ec9 85%);
  --font-body: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "SFMono-Regular", monospace;
  --shadow-soft: 0 12px 32px rgba(8, 19, 33, 0.32);
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --transition-base: 0.25s cubic-bezier(.4, .2, .2, 1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background: radial-gradient(circle at 0% 0%, rgba(61, 183, 255, 0.14), transparent 55%),
              radial-gradient(circle at 100% 100%, rgba(143, 123, 255, 0.1), transparent 60%),
              #040b14;
  color: var(--brand-text);
  min-height: 100vh;
  letter-spacing: 0.01em;
}

a {
  color: inherit;
}

a:hover,
a:focus {
  color: var(--brand-accent);
}

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

.container {
  width: min(1120px, 90vw);
  margin: 0 auto;
}

.site-header {
  background: rgba(4, 11, 20, 0.85);
  backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 0.85rem 0;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: var(--brand-text);
  font-weight: 600;
  font-size: 1.05rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--brand-gradient);
  display: grid;
  place-items: center;
  color: #08121f;
  font-weight: 800;
  font-size: 1rem;
  box-shadow: 0 10px 26px rgba(61, 183, 255, 0.4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--brand-text-soft);
  font-weight: 500;
  font-size: 0.92rem;
  letter-spacing: 0.02em;
  padding: 0.35rem 0;
  position: relative;
  transition: color var(--transition-base);
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.2rem;
  width: 100%;
  height: 2px;
  border-radius: 999px;
  background: var(--brand-gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.nav-links a:hover::after,
.nav-links a:focus::after,
.nav-links a.is-active::after {
  transform: scaleX(1);
}

.nav-links a:hover,
.nav-links a:focus,
.nav-links a.is-active {
  color: #fff;
}

.nav-toggle {
  display: none;
  border: none;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  padding: 0.5rem 0.6rem;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--brand-text);
  border-radius: 99px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.nav-toggle span + span {
  margin-top: 5px;
}

.page-content {
  padding: 4rem 0 5rem;
}

.section-title {
  font-size: clamp(2rem, 1.8rem + 1.5vw, 3rem);
  font-weight: 700;
  margin: 0 0 1rem;
  color: #fff;
}

.section-intro {
  max-width: 680px;
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--brand-text-soft);
  margin-bottom: 2.5rem;
}

.button-primary,
.button-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  border: none;
}

.button-primary {
  background: var(--brand-gradient);
  color: #08121f;
  box-shadow: 0 18px 42px rgba(61, 183, 255, 0.4);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--brand-text);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.button-primary:hover,
.button-secondary:hover {
  transform: translateY(-2px);
}

.page-section {
  margin-top: 5rem;
}

.card-grid {
  display: grid;
  gap: 1.75rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.feature-card,
.article-card,
.tool-card {
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.02));
  border: 1px solid var(--brand-border);
  border-radius: var(--radius-lg);
  padding: 1.8rem;
  box-shadow: var(--shadow-soft);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.feature-card:hover,
.article-card:hover,
.tool-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 22px 46px rgba(8, 19, 33, 0.55);
}

.feature-card h3,
.article-card h3,
.tool-card h3 {
  margin: 0;
  font-size: 1.2rem;
  color: #fff;
}

.feature-card p,
.article-card p,
.tool-card p {
  margin: 0;
  color: var(--brand-text-soft);
  line-height: 1.6;
}

.article-card time {
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(223, 235, 255, 0.7);
}

.article-card a {
  text-decoration: none;
}

.tool-card .tool-link {
  margin-top: auto;
  font-weight: 600;
  color: var(--brand-accent);
  text-decoration: none;
}

.site-footer {
  background: rgba(4, 11, 20, 0.92);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 2.5rem 0 2rem;
  margin-top: 4rem;
}

.site-footer p {
  margin: 0.4rem 0;
  color: var(--brand-text-soft);
  font-size: 0.9rem;
}

.site-footer a {
  color: var(--brand-accent);
  text-decoration: none;
}

.site-footer a:hover {
  color: #fff;
}

@media (max-width: 880px) {
  .nav-links {
    position: absolute;
    inset: calc(100% + 8px) 0 auto 0;
    background: rgba(4, 11, 20, 0.95);
    padding: 1rem 1.5rem;
    margin: 0;
    flex-direction: column;
    align-items: flex-start;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity var(--transition-base), transform var(--transition-base);
  }

  .nav-links[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-toggle {
    display: inline-flex;
    flex-direction: column;
    gap: 5px;
  }

  .site-nav {
    position: relative;
  }
}

@media (max-width: 640px) {
  .page-content {
    padding-top: 3rem;
  }

  .page-section {
    margin-top: 4rem;
  }
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}