/* ==========================================================================
   Srinivasa Rao Kaza — Personal Brand Site
   Design system: enterprise-grade, quiet, typography-led. No template noise.
   ========================================================================== */

:root {
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

  --max-w: 1180px;
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --tx: 160ms ease;

  --primary: #1a3764;
  --primary-strong: #0f2547;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eaf1ff;

  --bg: #ffffff;
  --bg-subtle: #f8fafc;
  --bg-muted: #eef2f7;
  --surface: #ffffff;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text-primary: #0f172a;
  --text-secondary: #45536b;
  --text-muted: #6b7994;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 6px 20px -8px rgba(15, 23, 42, 0.18);
  --shadow-lg: 0 20px 45px -20px rgba(15, 23, 42, 0.28);
}

html[data-theme="dark"] {
  --primary: #6ea1ff;
  --primary-strong: #a9c6ff;
  --accent: #5b9dff;
  --accent-hover: #86b7ff;
  --accent-soft: rgba(91, 157, 255, 0.14);

  --bg: #0a1120;
  --bg-subtle: #0e1729;
  --bg-muted: #141f36;
  --surface: #101a2e;
  --border: #1f2c47;
  --border-strong: #2c3c5e;
  --text-primary: #eef2f9;
  --text-secondary: #b7c2d6;
  --text-muted: #8593ac;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 30px -12px rgba(0, 0, 0, 0.55);
  --shadow-lg: 0 24px 60px -24px rgba(0, 0, 0, 0.65);
}

/* ---------- Reset & base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

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

img { max-width: 100%; display: block; }
a { color: var(--accent); }
h1, h2, h3, h4 { font-weight: 650; line-height: 1.2; letter-spacing: -0.01em; margin: 0; color: var(--text-primary); }
p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; }

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

.skip-link {
  position: absolute; left: 12px; top: -60px;
  background: var(--primary); color: #fff; padding: 10px 16px;
  border-radius: var(--r-sm); z-index: 200; transition: top var(--tx);
}
.skip-link:focus { top: 12px; }

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

/* ---------- Eyebrow / section headers ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; font-weight: 650; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 14px;
}
.eyebrow::before { content: ""; width: 18px; height: 2px; background: var(--accent); display: inline-block; border-radius: 2px; }

.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head h2 { font-size: clamp(1.6rem, 2.4vw, 2.1rem); margin-bottom: 14px; }
.section-head p { color: var(--text-secondary); font-size: 1.03rem; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head.center .eyebrow::before { display: none; }
.section-head-tight { margin-bottom: 24px; }

section { padding: 96px 0; border-bottom: 1px solid var(--border); }
section:last-of-type { border-bottom: none; }
.section-tight { padding: 64px 0; }
main section[id], #international { scroll-margin-top: 88px; }
.section-alt { background: var(--bg-subtle); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: var(--r-sm); font-size: 0.95rem; font-weight: 600;
  text-decoration: none; cursor: pointer; border: 1px solid transparent;
  transition: background var(--tx), color var(--tx), border-color var(--tx), transform var(--tx);
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-strong); }
.btn-secondary { background: transparent; color: var(--text-primary); border-color: var(--border-strong); }
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 8px 14px; font-size: 0.85rem; }
.btn svg { width: 16px; height: 16px; flex-shrink: 0; }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text-primary); font-weight: 700; flex-shrink: 0; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 9px; background: linear-gradient(145deg, var(--primary), var(--accent));
  color: #fff; display: flex; align-items: center; justify-content: center; font-size: 0.85rem; font-weight: 800;
  letter-spacing: -0.02em;
}
.brand-name { font-size: 1.02rem; white-space: nowrap; }
.brand-name span { display: block; font-size: 0.7rem; font-weight: 500; color: var(--text-muted); white-space: nowrap; }

.nav-links { display: flex; align-items: center; gap: 2px; flex-shrink: 0; }
.nav-link {
  color: var(--text-secondary); text-decoration: none; font-size: 0.85rem; font-weight: 500;
  padding: 7px 9px; border-radius: var(--r-sm); transition: color var(--tx), background var(--tx);
  white-space: nowrap;
}
.nav-link:hover { color: var(--text-primary); background: var(--bg-muted); }
.nav-link.active { color: var(--accent); }

.nav-actions { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.icon-btn {
  width: 38px; height: 38px; border-radius: 50%; border: 1px solid var(--border-strong);
  background: transparent; color: var(--text-secondary); display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: border-color var(--tx), color var(--tx);
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }
.icon-btn svg { width: 18px; height: 18px; }
.theme-icon-dark { display: none; }
html[data-theme="dark"] .theme-icon-light { display: none; }
html[data-theme="dark"] .theme-icon-dark { display: block; }

.menu-toggle { display: none; }

/* ---------- Hero ---------- */
.hero { padding: 76px 0 96px; border-bottom: 1px solid var(--border); position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: -20% -10% auto -10%; height: 420px;
  background: radial-gradient(60% 100% at 30% 0%, var(--accent-soft), transparent 70%);
  pointer-events: none;
}
.hero-grid {
  display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); gap: 56px; align-items: center; position: relative;
}
.hero-kicker {
  display: inline-flex; align-items: center; gap: 8px; font-size: 0.82rem; font-weight: 600;
  color: var(--accent); background: var(--accent-soft); border-radius: 999px; padding: 7px 14px; margin-bottom: 22px;
}
.hero h1 { font-size: clamp(2.2rem, 4vw, 3.2rem); margin-bottom: 16px; }
.hero-role { font-size: 1.1rem; color: var(--text-secondary); font-weight: 500; margin-bottom: 20px; }
.hero-intro { font-size: 1.05rem; color: var(--text-secondary); max-width: 560px; margin-bottom: 34px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 44px; }

.hero-stats { display: grid; grid-template-columns: repeat(3, auto); gap: 32px; }
.hero-stat strong { display: block; font-size: 1.5rem; color: var(--text-primary); font-weight: 700; }
.hero-stat span { font-size: 0.82rem; color: var(--text-muted); }

.hero-photo-wrap { display: flex; justify-content: center; position: relative; }
.hero-photo-frame {
  position: relative; width: min(370px, 100%); aspect-ratio: 4/5; border-radius: var(--r-lg);
  overflow: hidden; box-shadow: var(--shadow-lg); border: 1px solid var(--border);
  background: linear-gradient(160deg, var(--primary), var(--accent));
}
.hero-photo-frame img { width: 100%; height: 100%; object-fit: cover; }

/* ---------- Grids & cards ---------- */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-md);
  padding: 28px; transition: border-color var(--tx), box-shadow var(--tx), transform var(--tx);
}
.card:hover { border-color: var(--border-strong); box-shadow: var(--shadow-sm); }

.icon-tile {
  width: 46px; height: 46px; border-radius: var(--r-sm); background: var(--accent-soft); color: var(--accent);
  display: flex; align-items: center; justify-content: center; margin-bottom: 18px;
}
.icon-tile svg { width: 22px; height: 22px; }

/* About */
.capability-card { padding: 22px; display: flex; flex-direction: column; height: 100%; }
.capability-icon { width: 40px; height: 40px; margin-bottom: 14px; }
.capability-icon svg { width: 19px; height: 19px; }
.capability-card h3 { font-size: 0.96rem; margin-bottom: 6px; }
.capability-card p { font-size: 0.84rem; color: var(--text-secondary); line-height: 1.5; }

/* Chips */
.chip {
  display: inline-flex; align-items: center; font-size: 0.8rem; font-weight: 500; color: var(--text-secondary);
  background: var(--bg-muted); border: 1px solid var(--border); border-radius: 999px; padding: 5px 12px;
}

/* Expertise */
.expertise-card h3 { font-size: 1.05rem; margin-bottom: 10px; }
.expertise-card p { color: var(--text-secondary); font-size: 0.92rem; margin-bottom: 16px; }
.expertise-tags { display: flex; flex-wrap: wrap; gap: 8px; }

/* Certifications */
.section-compact { padding: 20px 0; }
.section-head-compact { margin-bottom: 8px; }
.section-head-compact .eyebrow { margin-bottom: 4px; }
.section-head-compact h2 { font-size: 1.1rem; }
.cert-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.cert-card-mini {
  display: flex; gap: 10px; align-items: flex-start; padding: 8px 14px;
  border: 1px solid var(--border); border-radius: var(--r-sm); background: var(--surface);
}
.cert-icon {
  width: 24px; height: 24px; min-width: 24px; min-height: 24px; max-width: 24px; max-height: 24px;
  border-radius: 6px; background: var(--accent-soft); color: var(--accent); overflow: hidden;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0; margin-top: 1px;
}
.cert-icon svg {
  width: 13px; height: 13px; max-width: 13px; max-height: 13px; min-width: 13px; min-height: 13px;
  display: block; flex-shrink: 0;
}
.cert-mini-issuer { font-weight: 650; font-size: 0.82rem; color: var(--text-primary); margin-bottom: 2px; }
.cert-mini-items { font-size: 0.73rem; color: var(--text-secondary); line-height: 1.4; }
.cert-footnote { margin-top: 6px; font-size: 0.76rem; color: var(--text-muted); text-align: center; }

/* Experience (subsections: Professional + International) */
.experience-sub { max-width: 960px; margin-top: 40px; }
.experience-sub:first-of-type { margin-top: 0; }
.experience-sub-wide { max-width: none; }
.experience-sub h3 { font-size: 1.2rem; margin-bottom: 10px; }
.experience-sub > p { color: var(--text-secondary); font-size: 1.03rem; max-width: 960px; }

/* International experience */
.intl-layout { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr); gap: 48px; align-items: center; margin-top: 32px; }
.world-map { position: relative; }
.world-map svg { width: 100%; height: auto; }
.world-map .pin { fill: var(--accent); }
.world-map .pin-ring { fill: none; stroke: var(--accent); stroke-width: 1.4; opacity: 0.5; }
.intl-list { display: grid; gap: 14px; }
.intl-item { display: flex; gap: 16px; align-items: flex-start; padding: 18px; border: 1px solid var(--border); border-radius: var(--r-md); background: var(--surface); }
.intl-flag {
  flex-shrink: 0; width: 38px; height: 38px; border-radius: var(--r-sm);
  background: var(--accent-soft); color: var(--accent); font-size: 0.72rem; font-weight: 700;
  letter-spacing: 0.03em; display: flex; align-items: center; justify-content: center;
}
.intl-item strong { display: block; font-size: 0.98rem; }
.intl-item .intl-duration { font-size: 0.8rem; color: var(--accent); font-weight: 600; }
.intl-item p { font-size: 0.86rem; color: var(--text-muted); margin-top: 2px; }

/* Knowledge Hub */
.khub-card {
  display: flex; flex-direction: column; height: 100%;
}
.khub-card .icon-tile { width: 52px; height: 52px; }
.khub-card .icon-tile svg { width: 26px; height: 26px; }
.khub-card h3 { font-size: 1.2rem; margin-bottom: 10px; }
.khub-card p { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 20px; flex-grow: 1; }
.khub-stats { display: flex; gap: 20px; margin-bottom: 22px; padding-top: 18px; border-top: 1px solid var(--border); }
.khub-stats div strong { display: block; font-size: 1.3rem; font-weight: 700; }
.khub-stats div span { font-size: 0.76rem; color: var(--text-muted); }

/* Architecture */
.arch-card .chip { margin-top: 4px; }
.arch-card h3 { font-size: 1.05rem; margin: 4px 0 10px; }
.arch-card p { color: var(--text-secondary); font-size: 0.92rem; margin-bottom: 16px; }

/* Projects */
.project-card { display: flex; flex-direction: column; }
.project-tag { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--accent); margin-bottom: 10px; }
.project-card h3 { font-size: 1.1rem; margin-bottom: 10px; }
.project-card p { color: var(--text-secondary); font-size: 0.92rem; margin-bottom: 18px; }
.project-links { margin-top: auto; display: flex; gap: 14px; }
.project-links a { font-size: 0.86rem; font-weight: 600; text-decoration: none; display: inline-flex; align-items: center; gap: 6px; }
.project-link-private { color: var(--text-secondary); }
.project-link-private:hover { color: var(--accent); }
.project-link-private svg { width: 14px; height: 14px; flex-shrink: 0; }
.section-disclaimer {
  margin-top: 36px; padding-top: 24px; border-top: 1px solid var(--border);
  max-width: 720px; margin-left: auto; margin-right: auto; text-align: center;
  font-size: 0.84rem; line-height: 1.6; color: var(--text-muted);
}
.section-disclaimer a { color: var(--text-muted); text-decoration: underline; }
.section-disclaimer a:hover { color: var(--accent); }

/* Insights */
.insight-card { position: relative; }
.badge-soon {
  display: inline-block; font-size: 0.7rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em;
  color: var(--text-muted); background: var(--bg-muted); border: 1px solid var(--border); border-radius: 999px;
  padding: 4px 10px; margin-bottom: 14px;
}
.insight-card h3 { font-size: 1.02rem; margin-bottom: 8px; color: var(--text-secondary); }
.insight-card p { font-size: 0.86rem; color: var(--text-muted); }

/* Contact */
.contact-grid { display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr); gap: 56px; }
.contact-card {
  display: flex; align-items: center; gap: 14px; padding: 18px 20px; border: 1px solid var(--border);
  border-radius: var(--r-md); text-decoration: none; color: var(--text-primary); margin-bottom: 14px; background: var(--surface);
  transition: border-color var(--tx), transform var(--tx);
}
.contact-card:hover { border-color: var(--accent); }
.contact-card strong { display: block; font-size: 0.95rem; }
.contact-card span { font-size: 0.82rem; color: var(--text-muted); }

.form-field { margin-bottom: 18px; }
.form-field label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 6px; }
.form-field input, .form-field textarea {
  width: 100%; padding: 12px 14px; border-radius: var(--r-sm); border: 1px solid var(--border-strong);
  background: var(--bg-subtle); color: var(--text-primary); font-family: inherit; font-size: 0.95rem;
  transition: border-color var(--tx); resize: vertical;
}
.form-field input:focus, .form-field textarea:focus { outline: none; border-color: var(--accent); }
.form-note { font-size: 0.8rem; color: var(--text-muted); margin-top: 10px; }
.form-status { font-size: 0.86rem; margin-top: 12px; display: none; }
.form-status.visible { display: block; }

/* Footer */
.footer { padding: 56px 0 32px; }
.footer-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 40px; flex-wrap: wrap; padding-bottom: 40px; }
.footer-cols { display: flex; gap: 64px; flex-wrap: wrap; }
.footer-col h4 { font-size: 0.88rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-primary); margin-bottom: 18px; }
.footer-col a { display: block; color: var(--text-secondary); text-decoration: none; font-size: 0.92rem; margin-bottom: 10px; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; padding-top: 28px; border-top: 1px solid var(--border); }
.footer-bottom p { font-size: 0.82rem; color: var(--text-muted); }
.footer-socials { display: flex; gap: 10px; }

/* Back to top */
.back-to-top {
  position: fixed; right: 24px; bottom: 24px; width: 44px; height: 44px; border-radius: 50%;
  background: var(--primary); color: #fff; display: flex; align-items: center; justify-content: center;
  border: none; cursor: pointer; box-shadow: var(--shadow-md); opacity: 0; pointer-events: none;
  transition: opacity var(--tx), transform var(--tx); z-index: 90;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top svg { width: 18px; height: 18px; }

/* ---------- Responsive ---------- */
/* Nav collapses earlier than the 980px content breakpoint below because 11 nav
   items no longer fit the horizontal bar past that width even after tightening
   link spacing/font-size — see assistant summary for the full explanation. */
@media (max-width: 1360px) {
  .nav-links { display: none; }
  .menu-toggle {
    display: flex; width: 38px; height: 38px; border-radius: var(--r-sm); border: 1px solid var(--border-strong);
    background: transparent; align-items: center; justify-content: center; cursor: pointer; color: var(--text-primary);
  }
  .menu-toggle svg { width: 20px; height: 20px; }
  .nav.menu-open .nav-links {
    display: flex; flex-direction: column; position: absolute; top: 68px; left: 0; right: 0; background: var(--surface);
    border-bottom: 1px solid var(--border); padding: 12px 24px 20px; gap: 4px; box-shadow: var(--shadow-md);
  }
}

@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-photo-wrap { order: -1; margin-bottom: 12px; }
  .hero-photo-frame { width: min(280px, 62%); }
  .intl-layout, .contact-grid { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-top { flex-direction: column; }
}

@media (max-width: 720px) {
  section { padding: 64px 0; }
  .hero { padding: 48px 0 64px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 20px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn { width: 100%; }
  .footer-cols { gap: 32px; }
  .section-compact { padding: 12px 0; }
  .section-head-compact { margin-bottom: 6px; }
  .cert-grid { grid-template-columns: 1fr; gap: 8px; }
  .cert-card-mini { padding: 7px 12px; }
}