/* ==========================================================================
   Aman Kumar Pandey — Technology Stack Styles
   Editorial, evidence-backed design system matching portfolio standards.
   ========================================================================== */

:root {
  color-scheme: dark;
  --bg: #030303;
  --surface: #0a0a0a;
  --surface-2: #121212;
  --text: #f5f5f5;
  --muted: #b0b0b0;
  --faint: #737373;
  --line: #262626;
  --line-soft: #1c1c1c;
  --strong: #404040;
  --focus: #ffffff;
  --panel-strong-bg: #111111;
  --panel-strong-text: #ffffff;
  --panel-strong-muted: #a0a0a0;
  --invert: #ffffff;
  --invert-text: #000000;
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.45);
  --radius: 3px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  --container: 1200px;
}

[data-theme="light"] {
  color-scheme: light;
  --bg: #ffffff;
  --surface: #f8f9fa;
  --surface-2: #f1f3f5;
  --text: #0d0d0d;
  --muted: #495057;
  --faint: #6c757d;
  --line: #e2e4e7;
  --line-soft: #ebeef1;
  --strong: #ced4da;
  --focus: #000000;
  --panel-strong-bg: #0d0d0d;
  --panel-strong-text: #ffffff;
  --panel-strong-muted: #b0b0b0;
  --invert: #000000;
  --invert-text: #ffffff;
  --shadow: 0 12px 30px rgba(0, 0, 0, 0.07);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

p, h1, h2, h3, h4 {
  margin: 0;
}

h1, h2, h3, h4 {
  font-family: var(--sans);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text);
}

.hero h1 {
  font-size: clamp(2.2rem, 4.8vw, 3.8rem);
  max-width: 800px;
}

.section-head h2,
.index h2 {
  font-size: clamp(1.6rem, 2.8vw, 2.3rem);
  max-width: 650px;
  line-height: 1.2;
}

.mono {
  font-family: var(--mono);
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 10px;
}

a {
  color: inherit;
  text-decoration: none;
}

:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 3px;
}

.shell {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.skip-link {
  position: fixed;
  left: 20px;
  top: 20px;
  z-index: 100;
  transform: translateY(-160%);
  background: var(--invert);
  color: var(--invert-text);
  padding: 10px 18px;
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: transform 160ms ease;
}

.skip-link:focus-visible {
  transform: translateY(0);
}

.top-line {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: transparent;
  z-index: 70;
  pointer-events: none;
}

.top-line span {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--text);
  transform-origin: left;
}

/* Site Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 0.84rem;
  font-weight: 700;
  border: 1px solid var(--line);
  padding: 6px 12px;
  border-radius: var(--radius);
}

.brand:hover {
  border-color: var(--text);
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  font-size: 0.9rem;
  color: var(--muted);
  transition: color 160ms ease;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--text);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  padding: 6px 10px;
  background: transparent;
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.04em;
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease;
}

.theme-toggle:hover {
  border-color: var(--text);
}

.theme-dot {
  width: 7px;
  height: 7px;
  border-radius: 999px;
  background: var(--text);
  box-shadow: 0 0 8px var(--text);
  transition: transform 160ms ease, background-color 160ms ease;
}

.theme-label {
  color: var(--muted);
}

.menu-btn {
  display: none;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
  font-size: 0.82rem;
  font-family: var(--mono);
  cursor: pointer;
}

.mobile-nav {
  display: none;
  padding: 10px 24px 18px;
  border-top: 1px solid var(--line);
}

.mobile-nav.open {
  display: block;
}

.mobile-nav a {
  display: block;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.94rem;
}

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

/* Hero Section */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.7fr);
  gap: 56px;
  padding: 56px 0 44px;
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  font-size: 1.05rem;
  color: var(--muted);
  margin-top: 18px;
  max-width: 650px;
}

.hero-aside {
  display: grid;
  gap: 16px;
  align-content: end;
}

.stat-block {
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.stat-block strong {
  display: block;
  font-size: 0.92rem;
  color: var(--text);
  margin: 3px 0;
}

.stat-block p {
  color: var(--muted);
  font-size: 0.82rem;
}

/* Quick Index */
.index {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(260px, 0.8fr);
  gap: 48px;
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--line);
}

.index-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 24px;
}

.index-grid a {
  border-top: 1px solid var(--line);
  padding: 10px 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: color 160ms ease;
}

.index-grid a span {
  color: var(--faint);
}

.index-grid a:hover {
  color: var(--text);
}

/* Sections */
.section {
  padding: 56px 0;
  border-bottom: 1px solid var(--line);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(260px, 0.75fr);
  gap: 40px;
  align-items: start;
  margin-bottom: 28px;
}

.section-head > p {
  color: var(--muted);
  font-size: 0.92rem;
  padding-top: 0.2rem;
}

.stack-grid {
  display: grid;
  gap: 18px;
}

.stack-grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.stack-grid.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.stack-card, .practice-grid article {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 24px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: border-color 160ms ease, transform 160ms ease;
}

.stack-card:hover, .practice-grid article:hover {
  border-color: var(--strong);
  transform: translateY(-2px);
}

.stack-card.featured {
  background: var(--panel-strong-bg);
  color: var(--panel-strong-text);
  border-color: var(--line);
}

.card-kicker {
  display: flex;
  justify-content: space-between;
  color: var(--faint);
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}

.featured .card-kicker {
  color: var(--panel-strong-muted);
}

.stack-card h3 {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.stack-card p {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.55;
  margin-bottom: 14px;
}

.featured p {
  color: var(--panel-strong-muted);
}

.evidence {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--faint);
  border-top: 1px solid var(--line);
  padding-top: 10px;
  margin-top: 12px;
}

.card-links {
  display: flex;
  gap: 12px;
  margin-top: 12px;
}

.card-links a {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--text);
  text-transform: uppercase;
}

.featured .card-links a {
  color: #ffffff;
}

/* Tool Table */
.tool-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
}

.tool-row {
  display: grid;
  grid-template-columns: 180px 1fr 1fr;
  gap: 16px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--line);
  font-size: 0.86rem;
  align-items: center;
}

.tool-row:last-child {
  border-bottom: 0;
}

.tool-row.header {
  background: var(--surface-2);
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--faint);
  letter-spacing: 0.08em;
  font-weight: 600;
}

.tool-row strong {
  color: var(--text);
}

.tool-row span {
  color: var(--muted);
}

/* Security Layout */
.security-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 24px;
}

.security-card {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 26px;
  border-radius: var(--radius);
}

.security-card h3 {
  font-size: 1.25rem;
  margin: 10px 0;
}

.security-card p {
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

.chip-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 18px 0;
}

.chip-list span {
  font-family: var(--mono);
  font-size: 0.7rem;
  border: 1px solid var(--line);
  padding: 4px 8px;
  border-radius: var(--radius);
  color: var(--muted);
}

.primary-link {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text);
  text-transform: uppercase;
  font-weight: 600;
}

.principles {
  display: grid;
  gap: 12px;
}

.principles > div {
  border: 1px solid var(--line);
  background: var(--surface);
  padding: 18px;
  border-radius: var(--radius);
}

.principles span {
  display: block;
  color: var(--faint);
  margin-bottom: 4px;
}

.principles strong {
  display: block;
  font-size: 0.95rem;
  color: var(--text);
}

.principles p {
  color: var(--muted);
  font-size: 0.84rem;
  margin-top: 4px;
}

/* Practice Grid */
.practice-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.practice-grid article span {
  display: block;
  color: var(--faint);
  margin-bottom: 8px;
}

.practice-grid h3 {
  font-size: 1.15rem;
  margin-bottom: 6px;
}

.practice-grid p {
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.55;
}

/* Site Footer */
.site-footer {
  padding: 32px 0 40px;
  border-top: 1px solid var(--line);
}

.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  color: var(--faint);
  font-size: 0.84rem;
}

.footer-grid strong {
  display: block;
  color: var(--text);
  font-size: 0.88rem;
}

.footer-grid > div:first-child span {
  display: block;
  margin-top: 2px;
}

.footer-grid > div:last-child {
  text-align: right;
}

.footer-grid a {
  display: inline-block;
  margin-top: 4px;
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.78rem;
}

/* Responsive */
@media (max-width: 1024px) {
  .nav-links {
    display: none;
  }
  .menu-btn {
    display: block;
  }
  .stack-grid.three {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .security-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero, .index, .section-head {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .stack-grid.two, .stack-grid.three, .practice-grid {
    grid-template-columns: 1fr;
  }
  .index-grid {
    grid-template-columns: 1fr;
  }
  .tool-row {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  .footer-grid {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
  .footer-grid > div:last-child {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
  }
}