/* =========================================================
   Rutvi Shetye — Personal Website
   Refined academic editorial aesthetic
   Palette: warm ivory · deep charcoal · muted slate blue
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500;1,600&family=Lora:ital,wght@0,400;0,500;1,400;1,500&family=DM+Mono:wght@300;400;500&display=swap');

:root {
  --bg:           #f7f4ee;
  --bg-alt:       #eeeae0;
  --bg-card:      #ffffff;
  --bg-hero:      #f0ece2;

  --text-primary:  #1a1715;
  --text-second:   #4a4540;
  --text-muted:    #8a8278;
  --text-light:    #b5afa6;

  --accent:        #3d5c7a;
  --accent-light:  #eaf0f6;
  --accent-mid:    #6a8aa8;
  --accent-warm:   #7a6248;
  --accent-warm-lt:#f0ebe3;

  --border:        #ddd8ce;
  --border-strong: #c2bbb0;

  --font-display:  'Playfair Display', Georgia, serif;
  --font-body:     'Lora', Georgia, serif;
  --font-ui:       'DM Mono', 'Courier New', monospace;

  --radius:    8px;
  --radius-sm: 4px;
  --transition: 0.22s ease;

  --shadow-sm: 0 1px 4px rgba(26,23,21,0.06);
  --shadow:    0 2px 12px rgba(26,23,21,0.09), 0 0 0 1px var(--border);
  --shadow-md: 0 4px 24px rgba(26,23,21,0.11), 0 0 0 1px var(--border-strong);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.82;
  min-height: 100vh;
  overflow-x: hidden;
}

h1,h2,h3,h4 { font-family: var(--font-display); font-weight: 600; line-height: 1.15; color: var(--text-primary); }
p            { color: var(--text-second); line-height: 1.85; }
img          { max-width: 100%; display: block; border-radius: var(--radius-sm); }
a            { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover      { color: var(--accent-warm); text-decoration: underline; text-underline-offset: 3px; }

/* ── Navigation ─────────────────────────────────────────── */
.nav {
  position: fixed; top:0; left:0; right:0; z-index:100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 2.75rem; height: 60px;
  background: rgba(247,244,238,0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-logo {
  font-family: var(--font-display); font-size: 1.1rem; font-weight: 600;
  color: var(--text-primary); text-decoration: none; letter-spacing: 0.01em;
}
.nav-logo:hover { color: var(--accent); text-decoration: none; }

.nav-links { display:flex; align-items:center; gap:0; list-style:none; }
.nav-links a {
  font-family: var(--font-ui); font-size: 0.68rem; letter-spacing: 0.13em;
  text-transform: uppercase; color: var(--text-muted);
  padding: 0.42rem 0.85rem; border-radius: var(--radius-sm);
  transition: all var(--transition); text-decoration: none;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); background: var(--accent-light); text-decoration: none; }

.nav-linkedin {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--font-ui); font-size: 0.67rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--text-muted) !important;
  border: 1px solid var(--border-strong) !important;
  padding: 0.36rem 0.85rem !important; border-radius: 20px;
  transition: all var(--transition) !important; text-decoration: none !important;
}
.nav-linkedin:hover { color: var(--accent) !important; border-color: var(--accent) !important; background: var(--accent-light) !important; text-decoration: none !important; }
.nav-linkedin svg { width: 13px; height: 13px; }

.nav-toggle { display:none; background:none; border:none; cursor:pointer; padding:0.4rem; flex-direction:column; gap:5px; }
.nav-toggle span { display:block; width:22px; height:1.5px; background:var(--text-primary); border-radius:1px; transition:all 0.3s; }

/* ── Layout ─────────────────────────────────────────────── */
.pt-nav { padding-top: 60px; }
.container        { max-width: 1100px; margin: 0 auto; padding: 0 2.5rem; }
.container-narrow { max-width: 820px; margin: 0 auto; padding: 0 2.5rem; }
.section          { padding: 5rem 0; }
.section-alt      { padding: 5rem 0; background: var(--bg-alt); }

/* ── Typography helpers ──────────────────────────────────── */
.label {
  display: block; font-family: var(--font-ui); font-size: 0.67rem;
  letter-spacing: 0.22em; text-transform: uppercase; color: var(--accent);
  margin-bottom: 0.6rem;
}
.section-title {
  font-size: clamp(1.9rem, 4.5vw, 3rem); font-weight: 600;
  color: var(--text-primary); line-height: 1.1;
}
.section-sub {
  margin-top: 0.55rem; font-size: 1rem; font-style: italic;
  color: var(--text-muted); font-family: var(--font-display); font-weight: 400;
}
.ruled { display:flex; align-items:center; gap:1rem; }
.ruled::after { content:''; flex:1; height:1px; background:var(--border); }
.rule       { height: 1px; background: var(--border); margin: 2rem 0; }
.rule-accent { width: 40px; height: 2px; background: var(--accent); margin: 0.9rem 0 0; opacity: 0.55; }

/* ── Cards ──────────────────────────────────────────────── */
.card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.75rem; box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), border-color var(--transition);
}
.card:hover { box-shadow: var(--shadow-md); border-color: var(--border-strong); }

/* ── Collapsible ─────────────────────────────────────────── */
.collapse-toggle {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; background: none; border: none; cursor: pointer;
  padding: 0.65rem 0; border-top: 1px solid var(--border);
  color: var(--text-muted); font-family: var(--font-ui);
  font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase;
  transition: color var(--transition); margin-top: 1rem; text-align: left;
}
.collapse-toggle:hover, .collapse-toggle.open { color: var(--accent); }
.collapse-arrow {
  width: 18px; height: 18px; border: 1px solid currentColor;
  border-radius: 50%; display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.collapse-arrow svg { width: 9px; height: 9px; transition: transform var(--transition); }
.collapse-toggle.open .collapse-arrow svg { transform: rotate(180deg); }
.collapse-body { max-height: 0; overflow: hidden; transition: max-height 0.48s cubic-bezier(0.4,0,0.2,1); }
.collapse-body.open { max-height: 9999px; }
.collapse-content {
  padding: 1rem 0 0.5rem 1.2rem;
  border-left: 2px solid var(--border-strong);
  margin-top: 0.2rem;
  font-size: 0.95rem; line-height: 1.85; color: var(--text-second);
}

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-family: var(--font-ui); font-size: 0.68rem; letter-spacing: 0.12em;
  text-transform: uppercase; padding: 0.58rem 1.15rem; border-radius: 20px;
  transition: all var(--transition); cursor: pointer; text-decoration: none;
}
.btn-primary { background: var(--accent); color: #fff; border: 1px solid var(--accent); }
.btn-primary:hover { background: #2e4a63; border-color: #2e4a63; color: #fff; text-decoration: none; }
.btn-outline { border: 1px solid var(--border-strong); color: var(--text-second); background: transparent; }
.btn-outline:hover { background: var(--bg-alt); border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn svg { width: 12px; height: 12px; }

/* ── Tags ────────────────────────────────────────────────── */
.tag {
  display: inline-block; font-family: var(--font-ui); font-size: 0.6rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  padding: 0.2rem 0.55rem; border-radius: 3px; margin: 0 0.2rem 0.2rem 0;
}
.tag-slate   { background: var(--accent-light); color: var(--accent); }
.tag-warm    { background: var(--accent-warm-lt); color: var(--accent-warm); }
.tag-neutral { background: var(--bg-alt); color: var(--text-muted); border: 1px solid var(--border); }

/* ── Footer ──────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border); padding: 2rem; text-align: center;
  font-family: var(--font-ui); font-size: 0.68rem; color: var(--text-muted);
  letter-spacing: 0.06em; background: var(--bg-alt);
}
footer a { color: var(--text-muted); text-decoration: none; }
footer a:hover { color: var(--accent); }

/* ── Animations ──────────────────────────────────────────── */
@keyframes fadeUp { from{opacity:0;transform:translateY(16px)} to{opacity:1;transform:translateY(0)} }
.animate-up   { animation: fadeUp 0.65s ease both; }
.animate-up-1 { animation: fadeUp 0.65s 0.1s ease both; }
.animate-up-2 { animation: fadeUp 0.65s 0.2s ease both; }
.animate-up-3 { animation: fadeUp 0.65s 0.3s ease both; }
.animate-up-4 { animation: fadeUp 0.65s 0.4s ease both; }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav { padding: 0 1.25rem; }
  .nav-links {
    position: fixed; top:60px; left:0; right:0;
    background: rgba(247,244,238,0.98); flex-direction:column;
    padding: 0.5rem; border-bottom: 1px solid var(--border);
    display: none; gap: 0;
  }
  .nav-links.open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 0.75rem 1rem; }
  .nav-toggle { display: flex; }
  .container, .container-narrow { padding: 0 1.25rem; }
  .section, .section-alt { padding: 3rem 0; }
}