/* =========================================================
   Khushi Prashant Mehta — Portfolio v2
   Monochrome / Editorial-Minimal Design System
   (direction: off-white + near-black, one indigo accent,
    glyph-marked sections, big confident display type)
   ========================================================= */

:root {
  /* --- Color --- */
  --bg:           #FAFAF8;
  --surface:      #FFFFFF;
  --ink:          #111113;
  --ink-soft:     #55545C;
  --ink-faint:    #9A98A1;
  --line:         #E5E4E0;
  --line-strong:  #D4D2CC;
  --accent:       #3B4CFF;
  --accent-ink:   #FFFFFF;
  --accent-tint:  #ECEDFF;
  --accent-dim:   #2B37CC;

  /* --- Type --- */
  --font-display: "Instrument Sans", "Helvetica Neue", Arial, sans-serif;
  --font-body:    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono:    "JetBrains Mono", "SFMono-Regular", Menlo, monospace;

  /* --- Layout --- */
  --container: 1200px;
  --container-narrow: 760px;
  --radius: 4px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* =========================================================
   Reset
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, figure, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
::selection { background: var(--accent); color: var(--accent-ink); }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.75rem);
}

section { padding-block: clamp(4rem, 8vw, 7.5rem); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.08;
  text-wrap: balance;
}

/* --- Eyebrow / glyph marker system ---
   ▶ = intro / orientation copy
   ⁕ = featured / grouped content
   ↗ = outbound or action link
*/
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.1rem;
}

.section-heading {
  font-size: clamp(2rem, 3.4vw, 2.75rem);
  max-width: 740px;
}

.section-lede {
  margin-top: 1.1rem;
  max-width: 600px;
  color: var(--ink-soft);
  font-size: 1.05rem;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 2rem;
  flex-wrap: wrap;
  margin-bottom: clamp(2.25rem, 5vw, 3.75rem);
}

/* =========================================================
   Buttons
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.9em 1.6em;
  border-radius: var(--radius);
  transition: transform 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease), border-color 0.3s var(--ease);
  white-space: nowrap;
}
.btn svg { width: 15px; height: 15px; flex-shrink: 0; transition: transform 0.3s var(--ease); }

.btn-primary { background: var(--ink); color: var(--bg); }
.btn-primary:hover { background: var(--accent); transform: translateY(-2px); }

.btn-ghost { border: 1px solid var(--line-strong); color: var(--ink); }
.btn-ghost:hover { border-color: var(--ink); background: var(--ink); color: var(--bg); transform: translateY(-2px); }

.btn-sm { padding: 0.65em 1.1em; font-size: 0.82rem; }

/* Underline-reveal text link */
.link-reveal {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
}
.link-reveal::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.35s var(--ease);
}
.link-reveal:hover::after { transform: scaleX(1); transform-origin: left; }

/* =========================================================
   Header / Nav
   ========================================================= */
.site-header {
  position: fixed;
  inset-inline: 0;
  top: 0;
  z-index: 100;
  padding-block: 1.25rem;
  transition: background 0.4s var(--ease), box-shadow 0.4s var(--ease), padding 0.4s var(--ease), backdrop-filter 0.4s var(--ease);
}
.site-header.is-scrolled {
  background: rgba(250, 246, 248, 0.86);
  backdrop-filter: blur(14px) saturate(140%);
  box-shadow: 0 1px 0 var(--line);
  padding-block: 0.85rem;
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; }

.brand {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}
.brand .accent-glyph { color: var(--accent); }

.navbar-list { display: flex; align-items: center; gap: clamp(1.2rem, 2.2vw, 2rem); }

.navbar-link {
  position: relative;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--ink-soft);
  padding-block: 0.3rem;
  transition: color 0.3s var(--ease);
}
.navbar-link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.35s var(--ease);
}
.navbar-link:hover, .navbar-link.is-active { color: var(--ink); }
.navbar-link:hover::after, .navbar-link.is-active::after { transform: scaleX(1); transform-origin: left; }

.header-actions { display: flex; align-items: center; gap: 1rem; }

.nav-toggle-btn {
  display: none;
  width: 38px; height: 38px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  position: relative;
}
.nav-toggle-btn .line {
  position: absolute; left: 10px; right: 10px; height: 1px;
  background: var(--ink);
  transition: transform 0.35s var(--ease), opacity 0.35s var(--ease);
}
.nav-toggle-btn .line-1 { top: 15px; }
.nav-toggle-btn .line-2 { bottom: 15px; }
.nav-toggle-btn[aria-expanded="true"] .line-1 { transform: translateY(4px) rotate(45deg); }
.nav-toggle-btn[aria-expanded="true"] .line-2 { transform: translateY(-4px) rotate(-45deg); }

.overlay { display: none; }

/* =========================================================
   Hero
   ========================================================= */
.hero { padding-top: clamp(8rem, 15vw, 11rem); padding-bottom: clamp(3.5rem, 7vw, 5.5rem); }

.hero-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 2rem;
  flex-wrap: wrap;
}

.hero-location {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--ink-faint);
  letter-spacing: 0.02em;
}

.hero-figure {
  width: 92px; height: 92px;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  flex-shrink: 0;
}
.hero-figure img {
  width: 100%; height: 100%; object-fit: cover;
  filter: grayscale(1) contrast(1.05);
  transition: filter 0.5s var(--ease);
}
.hero-figure:hover img { filter: grayscale(0) contrast(1.02); }

.hero-title {
  margin-top: 1.4rem;
  font-size: clamp(2.9rem, 8.5vw, 6.8rem);
  font-weight: 600;
}
.hero-title .accent-word { color: var(--accent); font-style: italic; font-family: "Instrument Sans", sans-serif; }

.hero-subtitle {
  margin-top: 0.9rem;
  font-family: var(--font-mono);
  font-size: clamp(0.95rem, 1.6vw, 1.1rem);
  color: var(--ink-soft);
  letter-spacing: 0.01em;
}
.hero-subtitle span { color: var(--line-strong); padding-inline: 0.5em; }

.hero-text {
  margin-top: 1.75rem;
  max-width: 600px;
  font-size: 1.1rem;
  color: var(--ink-soft);
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 0.85rem; margin-top: 2.1rem; }

.hero-stats {
  display: flex;
  gap: clamp(1.5rem, 4vw, 3rem);
  margin-top: 3.25rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line);
}
.hero-stat-num { font-family: var(--font-display); font-size: 1.6rem; font-weight: 600; display: block; }
.hero-stat-label { font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-faint); margin-top: 0.25rem; }

/* =========================================================
   About
   ========================================================= */
.about { border-top: 1px solid var(--line); }
.about .container { display: grid; grid-template-columns: 0.4fr 1fr; gap: clamp(2rem, 5vw, 4rem); }
.about-copy p { color: var(--ink-soft); font-size: 1.08rem; }
.about-copy p + p { margin-top: 1.1rem; }
.about-copy strong { color: var(--ink); font-weight: 600; }

.fact-list { display: grid; gap: 1.3rem; align-content: start; }
.fact-item { padding-bottom: 1.3rem; border-bottom: 1px solid var(--line); }
.fact-item:last-child { border-bottom: none; }
.fact-label { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--ink-faint); margin-bottom: 0.35rem; }
.fact-value { font-size: 0.96rem; }
.fact-value span { display: block; color: var(--ink-faint); font-size: 0.84rem; margin-top: 0.15rem; }

/* =========================================================
   Expertise
   ========================================================= */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.expertise-card { background: var(--bg); padding: clamp(1.7rem, 3vw, 2.3rem); transition: background 0.3s var(--ease); }
.expertise-card:hover { background: var(--surface); }
.expertise-num { font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); margin-bottom: 1.4rem; }
.expertise-title { font-size: 1.12rem; margin-bottom: 0.65rem; }
.expertise-text { color: var(--ink-soft); font-size: 0.92rem; }

/* =========================================================
   Skills
   ========================================================= */
.skills { border-top: 1px solid var(--line); }
.skills-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: clamp(1.6rem, 3vw, 2.4rem) clamp(2rem, 4vw, 3.5rem); }
.skill-group-title { font-family: var(--font-mono); font-size: 0.85rem; color: var(--ink); margin-bottom: 0.9rem; padding-bottom: 0.65rem; border-bottom: 1px solid var(--line); text-transform: uppercase; letter-spacing: 0.03em; }
.tag-list { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag {
  font-size: 0.8rem;
  padding: 0.45em 0.9em;
  border-radius: 100px;
  border: 1px solid var(--line-strong);
  color: var(--ink-soft);
  background: var(--surface);
  transition: all 0.3s var(--ease);
}
.tag:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-tint); }

/* =========================================================
   Experience
   ========================================================= */
.experience-layout { display: grid; grid-template-columns: 1fr 1.5fr; gap: clamp(2.5rem, 5vw, 4rem); align-items: start; }

.timeline { position: relative; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 10px; bottom: 10px; width: 1px; background: var(--line); }
.timeline-item { position: relative; padding-left: 2.5rem; padding-bottom: 2.6rem; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot { position: absolute; left: 0; top: 6px; width: 15px; height: 15px; border-radius: 50%; background: var(--bg); border: 2px solid var(--ink-faint); }
.timeline-item.is-current .timeline-dot { background: var(--accent); border-color: var(--accent); }
.timeline-date { font-family: var(--font-mono); font-size: 0.76rem; color: var(--ink-faint); margin-bottom: 0.4rem; text-transform: uppercase; letter-spacing: 0.03em; }
.timeline-role { font-size: 1.12rem; margin-bottom: 0.15rem; }
.timeline-org { font-size: 0.9rem; color: var(--accent); font-weight: 600; margin-bottom: 0.7rem; }
.timeline-org span { color: var(--ink-faint); font-weight: 400; }
.timeline-list { display: grid; gap: 0.5rem; }
.timeline-list li { position: relative; padding-left: 1.05rem; color: var(--ink-soft); font-size: 0.94rem; }
.timeline-list li::before { content: "\2014"; position: absolute; left: 0; top: 0; color: var(--line-strong); font-size: 0.8em; }

.education-block { border: 1px solid var(--line); padding: clamp(1.7rem, 3vw, 2.2rem); position: sticky; top: 7rem; }
.education-heading { font-family: var(--font-mono); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--accent); margin-bottom: 1.5rem; }
.edu-item + .edu-item { margin-top: 1.5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); }
.edu-degree { font-family: var(--font-display); font-size: 1.05rem; font-weight: 600; }
.edu-school { font-size: 0.9rem; color: var(--accent); font-weight: 600; margin-top: 0.25rem; }
.edu-date { font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-faint); margin-top: 0.3rem; text-transform: uppercase; }

/* =========================================================
   Projects
   ========================================================= */
.projects-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }

.project-card {
  background: var(--bg);
  padding: clamp(1.6rem, 2.6vw, 2rem);
  display: flex;
  flex-direction: column;
  min-height: 270px;
  transition: background 0.3s var(--ease);
}
.project-card:hover { background: var(--surface); }

.project-top { display: flex; align-items: flex-start; justify-content: space-between; margin-bottom: 1.5rem; }
.project-index { font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); }
.project-link-arrow {
  width: 30px; height: 30px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  display: grid; place-items: center;
  transition: all 0.35s var(--ease);
  flex-shrink: 0;
}
.project-link-arrow svg { width: 13px; height: 13px; }
.project-card:hover .project-link-arrow { background: var(--ink); border-color: var(--ink); color: var(--bg); transform: rotate(45deg); }

.project-title { font-size: 1.1rem; margin-bottom: 0.6rem; }
.project-text { font-size: 0.9rem; color: var(--ink-soft); flex-grow: 1; }
.project-tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 1.2rem; }
.project-tags span { font-family: var(--font-mono); font-size: 0.7rem; padding: 0.3em 0.65em; background: var(--accent-tint); color: var(--accent-dim); }

/* =========================================================
   Contact
   ========================================================= */
.contact {
  background: var(--ink);
  color: var(--bg);
  margin-inline: clamp(1.25rem, 4vw, 2.75rem);
  padding: clamp(3rem, 7vw, 5.5rem) clamp(1.75rem, 6vw, 5rem);
}
.contact-inner { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }
.contact .eyebrow { color: var(--accent); }
.contact-heading { color: var(--bg); font-size: clamp(2rem, 4vw, 2.9rem); }
.contact-text { margin-top: 1.1rem; color: rgba(250, 246, 248, 0.68); max-width: 480px; font-size: 1.02rem; }
.contact-open-line {
  margin-top: 1.4rem;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  padding: 0.5em 1em;
  border: 1px solid rgba(250, 246, 248, 0.25);
  border-radius: 100px;
}
.contact-open-line::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: #3DDC84; flex-shrink: 0; }
.contact-actions { margin-top: 2rem; display: flex; flex-wrap: wrap; gap: 1rem; }
.contact .btn-primary { background: var(--accent); color: var(--bg); }
.contact .btn-primary:hover { background: #FAFAF8; color: var(--ink); }
.contact .btn-ghost { border-color: rgba(250, 246, 248, 0.3); color: var(--bg); }
.contact .btn-ghost:hover { border-color: var(--bg); background: var(--bg); color: var(--ink); }

.contact-links { display: grid; gap: 1.05rem; justify-items: start; }
.contact-link-row {
  display: flex; align-items: center; justify-content: space-between; gap: 0.9rem;
  font-size: 0.98rem; color: var(--bg);
  padding-bottom: 1.05rem;
  border-bottom: 1px solid rgba(250, 246, 248, 0.16);
  width: 100%;
}
.contact-link-row:last-child { border-bottom: none; padding-bottom: 0; }
.contact-link-row span:first-child { color: rgba(250, 246, 248, 0.5); font-family: var(--font-mono); font-size: 0.78rem; }

/* =========================================================
   Footer
   ========================================================= */
.site-footer { padding-block: 2.2rem; }
.site-footer .container { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-faint); }
.footer-socials { display: flex; gap: 1.5rem; }
.footer-socials a { transition: color 0.3s var(--ease); }
.footer-socials a:hover { color: var(--accent); }

/* =========================================================
   Reveal animation
   ========================================================= */
[data-reveal] { opacity: 0; transform: translateY(24px); transition: opacity 0.8s var(--ease), transform 0.8s var(--ease); }
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 1024px) {
  .expertise-grid { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: repeat(2, 1fr); }
  .experience-layout { grid-template-columns: 1fr; }
  .education-block { position: static; }
  .about .container { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
}

@media (max-width: 860px) {
  .navbar {
    position: fixed; inset: 0 0 0 auto; width: min(78vw, 340px);
    background: var(--bg);
    padding: 6rem 2rem 2rem;
    transform: translateX(100%);
    transition: transform 0.5s var(--ease);
    z-index: 90;
    box-shadow: -20px 0 60px -20px rgba(0,0,0,0.2);
  }
  .navbar[data-nav-open] { transform: translateX(0); }
  .navbar-list { flex-direction: column; align-items: flex-start; gap: 1.5rem; }
  .navbar-link { font-size: 1.05rem; }
  .nav-toggle-btn { display: block; }
  .header-actions .btn-primary.btn-sm { display: none; }
  .overlay {
    display: block; position: fixed; inset: 0;
    background: rgba(17,17,19,0.35);
    opacity: 0; pointer-events: none;
    transition: opacity 0.4s var(--ease);
    z-index: 80;
  }
  .overlay[data-overlay-active] { opacity: 1; pointer-events: auto; }
}

@media (max-width: 700px) {
  .expertise-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .contact-inner { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; row-gap: 1.2rem; }
}