/* =========================================================
   Muhammad Azam — Portfolio
   "Frost" design system: cool slate/blue palette, glass cards
   ========================================================= */

:root {
  /* Frost palette — light */
  --bg: #f3f7fc;
  --bg-soft: #e9f1f9;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --border: rgba(16, 42, 67, 0.10);
  --border-strong: rgba(16, 42, 67, 0.18);

  --text: #0f2438;
  --text-muted: #4d6478;
  --text-faint: #7f93a3;

  --primary: #2563eb;
  --primary-dark: #1742a8;
  --primary-soft: #e5edfd;
  --accent: #0891b2;
  --accent-soft: #dff5f8;

  --success: #15803d;
  --success-soft: #e4f6ea;
  --warning: #b45309;
  --warning-soft: #fdf1e0;

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;

  --shadow-sm: 0 1px 2px rgba(16, 42, 67, 0.06);
  --shadow: 0 8px 24px -8px rgba(16, 42, 67, 0.16);
  --shadow-lg: 0 24px 60px -20px rgba(16, 42, 67, 0.28);

  --container: 1180px;
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  color-scheme: light;
}

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

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1100px 520px at 85% -10%, #dbe9fb 0%, transparent 60%),
    radial-gradient(900px 480px at -10% 20%, #e2f3f5 0%, transparent 55%),
    var(--bg);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  line-height: 1.55;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 0.5em; font-weight: 700; letter-spacing: -0.01em; }
p { margin: 0 0 1em; color: var(--text-muted); }
ul { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 20px;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5em;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 10px 24px -8px rgba(37, 99, 235, 0.55);
}
.btn-primary:hover { box-shadow: 0 14px 28px -8px rgba(37, 99, 235, 0.65); }

.btn-ghost {
  background: var(--surface);
  border-color: var(--border-strong);
  color: var(--text);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }

.btn-block { width: 100%; }
.btn-sm { min-height: 38px; padding: 0 16px; font-size: 0.85rem; }

/* ---------- Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(243, 247, 252, 0.78);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--text);
}
.brand-mark {
  width: 34px; height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.85rem; font-weight: 800;
  flex-shrink: 0;
}
.nav-links {
  display: none;
  align-items: center;
  gap: 28px;
  font-weight: 500;
  font-size: 0.94rem;
}
.nav-links a { color: var(--text-muted); transition: color 0.15s ease; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--primary); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.nav-actions .btn { display: none; }

.nav-toggle {
  display: inline-flex;
  align-items: center; justify-content: center;
  width: 44px; height: 44px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  cursor: pointer;
}
.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 18px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  position: relative;
  transition: transform 0.2s ease, opacity 0.2s ease;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }
.nav-toggle[aria-expanded="true"] span { background: transparent; }
.nav-toggle[aria-expanded="true"] span::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span::after { transform: translateY(-6px) rotate(-45deg); }

.mobile-menu {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 12px 20px 20px;
  border-top: 1px solid var(--border);
  background: rgba(243, 247, 252, 0.96);
}
.mobile-menu.is-open { display: flex; }
.mobile-menu a {
  padding: 12px 6px;
  font-weight: 600;
  color: var(--text);
  border-radius: var(--radius-sm);
}
.mobile-menu a:hover { background: var(--surface); color: var(--primary); }
.mobile-menu .btn { margin-top: 8px; }

/* ---------- Sections ---------- */
.section { padding: 56px 0; }
.section-head { max-width: 640px; margin-bottom: 32px; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 10px;
}
.eyebrow::before {
  content: "";
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

/* ---------- Hero ---------- */
.hero { padding: 56px 0 40px; }
.hero-grid {
  display: grid;
  gap: 32px;
  align-items: center;
}
.hero h1 {
  font-size: clamp(2rem, 6vw, 3.2rem);
  margin-bottom: 0.4em;
}
.hero .lede { font-size: 1.08rem; max-width: 54ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 10px 18px;
  margin-top: 28px; font-size: 0.88rem; color: var(--text-faint);
}
.hero-meta span { display: inline-flex; align-items: center; gap: 8px; }
.hero-meta i { color: var(--primary); }

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
}
.hero-card h3 { font-size: 0.95rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-faint); margin-bottom: 14px; }
.stat-row { display: flex; justify-content: space-between; padding: 10px 0; border-top: 1px solid var(--border); }
.stat-row:first-of-type { border-top: none; }
.stat-row dt { color: var(--text-muted); font-size: 0.88rem; }
.stat-row dd { margin: 0; font-weight: 700; }

/* ---------- Stack strip ---------- */
.stack-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.83rem;
  font-weight: 600;
  color: var(--text-muted);
}
.tag i { color: var(--primary); font-size: 0.8em; }

/* ---------- Project cards ---------- */
.project-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}
.project-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--border-strong); }
.project-card-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.project-card h3 { font-size: 1.25rem; margin-bottom: 4px; }
.project-card .status-pill { flex-shrink: 0; }
.project-card .tags { display: flex; flex-wrap: wrap; gap: 6px; margin: 4px 0 2px; }
.project-card .tags .tag { padding: 4px 10px; font-size: 0.74rem; }
.project-card-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: auto; padding-top: 6px; }

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.status-live { background: var(--success-soft); color: var(--success); }
.status-note { background: var(--warning-soft); color: var(--warning); }

/* ---------- Timeline (experience) ---------- */
.timeline { display: flex; flex-direction: column; gap: 0; }
.timeline-item {
  position: relative;
  padding: 4px 0 28px 28px;
  border-left: 2px solid var(--border);
}
.timeline-item:last-child { border-left-color: transparent; padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute; left: -7px; top: 6px;
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--primary);
}
.timeline-item .role { font-weight: 700; font-size: 1.02rem; }
.timeline-item .meta { font-size: 0.85rem; color: var(--text-faint); margin-bottom: 8px; }
.timeline-item ul { display: flex; flex-direction: column; gap: 6px; }
.timeline-item li { color: var(--text-muted); font-size: 0.93rem; position: relative; padding-left: 16px; }
.timeline-item li::before { content: "—"; position: absolute; left: 0; color: var(--text-faint); }

/* ---------- Contact ---------- */
.contact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}
.contact-grid { display: grid; grid-template-columns: 1fr; gap: 14px; margin-top: 20px; }
.contact-link {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-solid);
  font-weight: 600;
  font-size: 0.92rem;
  min-height: 44px;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.contact-link:hover { border-color: var(--primary); transform: translateY(-2px); }
.contact-link i {
  width: 38px; height: 38px;
  border-radius: 10px;
  background: var(--primary-soft);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.contact-link small { display: block; font-weight: 500; color: var(--text-faint); font-size: 0.76rem; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
  margin-top: 40px;
}
.footer-row {
  display: flex; flex-direction: column; gap: 14px;
  align-items: flex-start;
  font-size: 0.85rem;
  color: var(--text-faint);
}
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer-links a:hover { color: var(--primary); }

/* ---------- Case study pages ---------- */
.cs-hero { padding: 40px 0 8px; }
.cs-back {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.85rem; font-weight: 600; color: var(--text-muted);
  margin-bottom: 20px;
}
.cs-back:hover { color: var(--primary); }
.cs-title-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 10px; }
.cs-hero h1 { font-size: clamp(1.8rem, 5vw, 2.7rem); margin-bottom: 6px; }
.cs-summary { font-size: 1.05rem; max-width: 68ch; }
.cs-demo-bar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 22px 0 10px;
  backdrop-filter: blur(10px);
}
.cs-demo-bar .note {
  font-size: 0.85rem;
  color: var(--text-muted);
  flex: 1 1 260px;
}
.cs-note {
  display: flex; gap: 12px;
  background: var(--warning-soft);
  border: 1px solid rgba(180, 83, 9, 0.2);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 22px 0;
  font-size: 0.9rem;
  color: #7c3d09;
}
.cs-note i { flex-shrink: 0; margin-top: 2px; }
.cs-note strong { display: block; margin-bottom: 4px; color: #7c3d09; }

.cs-block { padding: 34px 0; border-top: 1px solid var(--border); }
.cs-block:first-of-type { border-top: none; }
.cs-block h2 {
  font-size: 1.5rem;
  display: flex; align-items: center; gap: 10px;
  margin-bottom: 18px;
}
.cs-block h2 .num {
  width: 30px; height: 30px;
  border-radius: 9px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 0.82rem;
  display: inline-flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.cs-two-col { display: grid; grid-template-columns: 1fr; gap: 32px; }

.stack-tags { display: flex; flex-wrap: wrap; gap: 10px; }

.result-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 6px; }
.result-tile {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
}
.result-tile .num { font-size: 1.5rem; font-weight: 800; color: var(--primary); display: block; }
.result-tile .label { font-size: 0.82rem; color: var(--text-faint); }

.cs-links { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- Architecture diagram (CSS/SVG driven, no external images) ---------- */
.diagram {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  overflow-x: auto;
}
.diagram-flow {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 260px;
}
.diagram-row { display: flex; gap: 10px; flex-wrap: wrap; }
.diagram-step {
  flex: 1 1 200px;
  background: var(--primary-soft);
  border: 1px solid rgba(37, 99, 235, 0.25);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.diagram-step.accent { background: var(--accent-soft); border-color: rgba(8, 145, 178, 0.25); }
.diagram-step .step-label { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-faint); font-weight: 700; }
.diagram-step .step-title { font-weight: 700; font-size: 0.95rem; margin-top: 2px; }
.diagram-step .step-desc { font-size: 0.82rem; color: var(--text-muted); margin-top: 4px; }
.diagram-arrow { align-self: center; color: var(--text-faint); font-size: 1.1rem; }
.diagram-arrow.down { transform: rotate(90deg); align-self: flex-start; margin-left: 20px; }

.pipeline-img {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

/* ---------- Resume page ---------- */
.resume-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px;
  text-align: center;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}
.resume-card .icon {
  width: 68px; height: 68px;
  margin: 0 auto 18px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.6rem;
}
.resume-highlights {
  display: grid; grid-template-columns: 1fr; gap: 12px;
  margin-top: 28px; text-align: left;
}
.resume-highlights li {
  display: flex; gap: 10px;
  font-size: 0.92rem; color: var(--text-muted);
  padding: 12px 14px;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}
.resume-highlights i { color: var(--success); margin-top: 3px; }

/* ---------- Breakpoints ---------- */
@media (min-width: 480px) {
  .project-grid { grid-template-columns: repeat(2, 1fr); }
  .result-grid { grid-template-columns: repeat(4, 1fr); }
  .diagram-row { flex-wrap: nowrap; }
  .contact-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 768px) {
  .nav-links { display: flex; }
  .nav-actions .btn { display: inline-flex; }
  .nav-toggle { display: none; }
  .mobile-menu { display: none !important; }

  .hero-grid { grid-template-columns: 1.15fr 0.85fr; }
  .cs-two-col { grid-template-columns: 1.3fr 0.7fr; }
  .footer-row { flex-direction: row; align-items: center; justify-content: space-between; }
}

@media (min-width: 1024px) {
  .project-grid { grid-template-columns: repeat(3, 1fr); }
  .section { padding: 72px 0; }
  .hero { padding: 76px 0 56px; }
}