/* ============================================================
   Khairul Islam — DevOps Engineer Portfolio
   Design tokens
   ============================================================ */
:root {
  --bg: #0B0D10;
  --surface: #14171B;
  --surface-raised: #1B1F24;
  --border: #262B31;
  --text-primary: #EDEFF1;
  --text-secondary: #98A0A8;
  --text-muted: #676F78;
  --accent: #4FB3FF;
  --accent-dim: rgba(79, 179, 255, 0.12);
  --accent-line: rgba(79, 179, 255, 0.35);

  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  --space-24: 96px;

  --radius: 8px;
  --radius-sm: 5px;
  --max-width: 1180px;
  --content-width: 700px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

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

::selection { background: var(--accent-dim); color: var(--text-primary); }

/* Focus states — visible everywhere */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #06121D;
  padding: 10px 16px;
  z-index: 1000;
  font-weight: 600;
  border-radius: 0 0 6px 0;
}
.skip-link:focus { left: 0; }

/* Layout helpers */
.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}
.prose { max-width: var(--content-width); }

section { padding: var(--space-24) 0; border-top: 1px solid var(--border); }
section:first-of-type { border-top: none; }

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-6);
  margin-bottom: var(--space-12);
  flex-wrap: wrap;
}
.section-head h2 {
  font-size: clamp(1.5rem, 1.2rem + 1vw, 2rem);
  margin: 0;
  letter-spacing: -0.01em;
}
.section-num {
  font-family: var(--font-mono);
  color: var(--text-muted);
  font-size: 0.85rem;
}
.section-lede {
  color: var(--text-secondary);
  max-width: 620px;
  margin: var(--space-2) 0 0;
}

h1, h2, h3, h4 { font-weight: 600; letter-spacing: -0.01em; }
p { color: var(--text-secondary); margin: 0 0 var(--space-4); }

/* ============================================================
   Header / Nav
   ============================================================ */
header.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 13, 16, 0.85);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: 0.98rem;
}
.brand-mark {
  width: 30px;
  height: 30px;
  border: 1px solid var(--accent-line);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent);
}
nav.primary-nav { display: flex; align-items: center; gap: var(--space-8); }
nav.primary-nav a {
  font-size: 0.92rem;
  color: var(--text-secondary);
  transition: color 0.15s var(--ease);
}
nav.primary-nav a:hover { color: var(--text-primary); }
.nav-cta {
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--text-primary) !important;
  font-size: 0.88rem;
  transition: border-color 0.15s var(--ease), background 0.15s var(--ease);
}
.nav-cta:hover { border-color: var(--accent-line); background: var(--accent-dim); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  color: var(--text-primary);
  cursor: pointer;
}

.mobile-sheet {
  display: none;
  position: fixed;
  inset: 64px 0 0 0;
  background: var(--bg);
  z-index: 99;
  padding: var(--space-8) var(--space-6);
  overflow-y: auto;
}
.mobile-sheet.open { display: block; }
.mobile-sheet a {
  display: block;
  padding: var(--space-4) 0;
  font-size: 1.15rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}

/* ============================================================
   Hero
   ============================================================ */
.hero {
  padding: var(--space-24) 0 var(--space-16);
  border-top: none;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: var(--space-16);
  align-items: center;
}
.eyebrow {
  font-family: var(--font-mono);
  color: var(--accent);
  font-size: 0.85rem;
  margin-bottom: var(--space-4);
}
.hero h1 {
  font-size: clamp(2.4rem, 1.9rem + 2vw, 3.4rem);
  line-height: 1.08;
  margin: 0 0 var(--space-3);
}
.hero .role {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}
.hero .role .sep { color: var(--text-muted); margin: 0 8px; }
.hero .statement {
  max-width: 540px;
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-8);
}
.cta-row { display: flex; gap: var(--space-4); flex-wrap: wrap; margin-bottom: var(--space-8); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: transform 0.15s var(--ease), background 0.15s var(--ease), border-color 0.15s var(--ease);
}
.btn-primary {
  background: var(--accent);
  color: #06121D;
  border: 1px solid var(--accent);
}
.btn-primary:hover { background: #6cc0ff; }
.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--accent-line); background: var(--accent-dim); }

.social-row { display: flex; gap: var(--space-6); }
.social-row a {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: color 0.15s var(--ease);
}
.social-row a:hover { color: var(--accent); }
.social-row svg { width: 16px; height: 16px; }

/* Hero pipeline diagram */
.pipeline-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-6);
}
.pipeline-card .pipeline-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}
.pipeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.pipeline-node {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px 0;
  position: relative;
}
.pipeline-node:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 13px;
  top: 34px;
  width: 1px;
  height: 22px;
  background: var(--border);
}
.pipeline-dot {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 1px solid var(--accent-line);
  background: var(--accent-dim);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  flex-shrink: 0;
}
.pipeline-label { font-size: 0.92rem; color: var(--text-primary); }
.pipeline-sub { font-size: 0.78rem; color: var(--text-muted); font-family: var(--font-mono); }

/* ============================================================
   Capability grid
   ============================================================ */
.cap-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.cap-tile {
  background: var(--surface);
  padding: var(--space-6);
  transition: background 0.15s var(--ease);
}
.cap-tile:hover { background: var(--surface-raised); }
.cap-tile h3 {
  font-size: 0.98rem;
  margin: 0 0 6px;
}
.cap-tile p { font-size: 0.86rem; margin: 0; color: var(--text-muted); }

.tag-row { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-6); }
.tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 5px 10px;
  border-radius: 999px;
}

/* ============================================================
   About
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: var(--space-16);
  align-items: start;
}
.about-photo {
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
}
.about-photo img { width: 100%; height: 100%; object-fit: cover; }

.principle-list { margin-top: var(--space-8); display: grid; gap: var(--space-4); }
.principle {
  display: grid;
  grid-template-columns: 20px 1fr;
  gap: var(--space-3);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}
.principle:last-child { border-bottom: none; }
.principle-mark { color: var(--accent); font-family: var(--font-mono); }
.principle h4 { margin: 0 0 4px; font-size: 0.98rem; }
.principle p { margin: 0; font-size: 0.9rem; }

/* ============================================================
   Experience
   ============================================================ */
.exp-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-8);
}
.exp-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-6);
  border-bottom: 1px solid var(--border);
}
.exp-head h3 { margin: 0 0 4px; font-size: 1.15rem; }
.exp-head .exp-role { color: var(--accent); font-size: 0.92rem; }
.exp-head .exp-dates {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  white-space: nowrap;
}
.exp-list { display: grid; gap: var(--space-3); margin: 0; padding: 0; list-style: none; }
.exp-list li {
  display: grid;
  grid-template-columns: 20px 1fr;
  gap: var(--space-3);
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.55;
}
.exp-list li::before {
  content: "›";
  color: var(--accent);
  font-family: var(--font-mono);
}

/* ============================================================
   Projects
   ============================================================ */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-6);
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.project-card .proj-index {
  font-family: var(--font-mono);
  color: var(--text-muted);
  font-size: 0.78rem;
}
.project-card h3 { margin: 0; font-size: 1.05rem; }
.project-card p { font-size: 0.92rem; margin: 0; }

/* ============================================================
   Resume
   ============================================================ */
.resume-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-8);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
}
.resume-panel h3 { margin: 0 0 6px; }
.resume-panel p { margin: 0; max-width: 480px; }

.edu-cert-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  margin-top: var(--space-8);
}
.edu-cert-grid h4 {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  text-transform: none;
  margin: 0 0 var(--space-3);
}
.edu-cert-grid ul { list-style: none; margin: 0; padding: 0; display: grid; gap: var(--space-2); }
.edu-cert-grid li {
  font-size: 0.95rem;
  color: var(--text-primary);
  padding: var(--space-3);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}
.edu-cert-grid li span { display: block; font-size: 0.82rem; color: var(--text-muted); margin-top: 2px; }

/* ============================================================
   Contact / Footer
   ============================================================ */
.contact-section { text-align: left; }
.contact-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-16);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-8);
  flex-wrap: wrap;
}
.contact-panel h2 { margin: 0 0 var(--space-2); font-size: 1.8rem; }
.contact-panel p { margin: 0; }
.contact-links { display: flex; flex-direction: column; gap: var(--space-3); align-items: flex-start; }
.contact-links a {
  font-size: 0.98rem;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: color 0.15s var(--ease);
}
.contact-links a:hover { color: var(--accent); }

footer.site-footer {
  border-top: 1px solid var(--border);
  padding: var(--space-8) 0;
}
.footer-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ============================================================
   Reveal on scroll (subtle, respects reduced-motion via media query above)
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
.reveal.in-view { opacity: 1; transform: translateY(0); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: var(--space-8); }
  .about-grid { grid-template-columns: 1fr; }
  .about-photo { max-width: 220px; }
  nav.primary-nav { display: none; }
  .nav-toggle { display: grid; place-items: center; }
  .contact-panel { flex-direction: column; align-items: flex-start; }
  .edu-cert-grid { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
  section { padding: var(--space-16) 0; }
  .hero { padding-top: var(--space-16); }
  .resume-panel { flex-direction: column; align-items: flex-start; }
}