/* ============================================================
   Charan Tej Gayapu — Portfolio
   Clinical Data Management • AI • Healthcare Analytics
   ============================================================ */

:root {
  --navy: #0A3D62;
  --navy-dark: #072C47;
  --navy-light: #1B5E8C;
  --teal: #00A8A8;
  --teal-light: #4DD0CE;
  --teal-dark: #007F7F;
  --bg: #F5F7FA;
  --bg-alt: #FFFFFF;
  --card: #FFFFFF;
  --card-glass: rgba(255, 255, 255, 0.75);
  --text: #1F2D3D;
  --text-muted: #5A6B7B;
  --border: #E2E8F0;
  --shadow: 0 4px 24px rgba(10, 61, 98, 0.08);
  --shadow-lg: 0 12px 40px rgba(10, 61, 98, 0.14);
  --radius: 16px;
  --font-head: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;
}

[data-theme="dark"] {
  --bg: #0B1622;
  --bg-alt: #101E2E;
  --card: #14263A;
  --card-glass: rgba(20, 38, 58, 0.75);
  --text: #E6EEF5;
  --text-muted: #93A7BA;
  --border: #1F3851;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  transition: background 0.3s, color 0.3s;
}
img { max-width: 100%; display: block; }
a { color: var(--teal); text-decoration: none; }
a:hover { color: var(--teal-dark); }
h1, h2, h3, h4 { font-family: var(--font-head); color: var(--text); line-height: 1.25; }

.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }
section { padding: 72px 0; }

/* ---------- Navbar ---------- */
.navbar {
  position: sticky; top: 0; z-index: 1000;
  background: var(--card-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1240px; margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand {
  font-family: var(--font-head); font-weight: 700; font-size: 1.15rem;
  color: var(--text); display: flex; align-items: center; gap: 10px; white-space: nowrap;
}
.brand-badge {
  width: 38px; height: 38px; border-radius: 10px; flex: none;
  background: linear-gradient(135deg, var(--navy), var(--teal));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; font-weight: 700;
}
.nav-links { display: flex; gap: 4px; list-style: none; flex-wrap: wrap; }
.nav-links a {
  display: block; padding: 8px 12px; border-radius: 8px;
  color: var(--text-muted); font-size: 0.86rem; font-weight: 500;
}
.nav-links a:hover { color: var(--teal); background: rgba(0, 168, 168, 0.08); }
.nav-links a.active { color: #fff; background: var(--teal); }
.nav-actions { display: flex; align-items: center; gap: 10px; }
.theme-toggle {
  border: 1px solid var(--border); background: var(--card); color: var(--text);
  width: 38px; height: 38px; border-radius: 10px; cursor: pointer; font-size: 1rem;
  display: flex; align-items: center; justify-content: center; transition: transform 0.2s;
}
.theme-toggle:hover { transform: rotate(20deg); }
.hamburger {
  display: none; border: 1px solid var(--border); background: var(--card); color: var(--text);
  width: 38px; height: 38px; border-radius: 10px; cursor: pointer; font-size: 1.1rem;
}

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(140deg, var(--navy-dark) 0%, var(--navy) 55%, var(--teal-dark) 100%);
  color: #fff; padding: 96px 0;
}
.hero::before, .hero::after {
  content: ""; position: absolute; border-radius: 50%; filter: blur(60px); opacity: 0.35;
  animation: float 9s ease-in-out infinite alternate;
}
.hero::before { width: 420px; height: 420px; background: var(--teal); top: -120px; right: -80px; }
.hero::after { width: 340px; height: 340px; background: var(--teal-light); bottom: -140px; left: -60px; animation-delay: 3s; }
@keyframes float { from { transform: translateY(0) scale(1); } to { transform: translateY(30px) scale(1.08); } }

.hero-grid {
  position: relative; z-index: 2;
  display: grid; grid-template-columns: 1.4fr 1fr; gap: 48px; align-items: center;
}
.hero h1 { color: #fff; font-size: clamp(2rem, 4.5vw, 3.1rem); margin: 10px 0 6px; }
.hero .eyebrow {
  display: inline-block; padding: 6px 14px; border-radius: 999px; font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.12); border: 1px solid rgba(255, 255, 255, 0.25);
  letter-spacing: 0.06em; text-transform: uppercase;
}
.hero .roles { color: var(--teal-light); font-weight: 600; font-size: 1.1rem; min-height: 1.7em; }
.hero p.summary { margin: 18px 0 28px; color: rgba(255, 255, 255, 0.88); max-width: 560px; }
.hero-photo {
  width: 260px; height: 260px; border-radius: 50%; margin: 0 auto;
  background: linear-gradient(135deg, var(--teal), var(--teal-light));
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-head); font-size: 4.5rem; font-weight: 700; color: var(--navy-dark);
  border: 6px solid rgba(255, 255, 255, 0.25); box-shadow: var(--shadow-lg);
}

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 12px; font-weight: 600; font-size: 0.92rem;
  border: none; cursor: pointer; transition: transform 0.2s, box-shadow 0.2s;
  font-family: var(--font-body);
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-primary { background: var(--teal); color: #fff; }
.btn-primary:hover { color: #fff; }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255, 255, 255, 0.5); }
.btn-outline:hover { border-color: var(--teal-light); color: var(--teal-light); }
.btn-dark { background: var(--navy); color: #fff; }
.btn-dark:hover { color: #fff; }
.btn-row { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- Page header (inner pages) ---------- */
.page-head {
  background: linear-gradient(140deg, var(--navy-dark), var(--navy) 60%, var(--teal-dark));
  color: #fff; padding: 64px 0 56px; text-align: center;
}
.page-head h1 { color: #fff; font-size: clamp(1.8rem, 3.5vw, 2.6rem); }
.page-head p { color: rgba(255, 255, 255, 0.85); max-width: 640px; margin: 10px auto 0; }

/* ---------- Section headings ---------- */
.section-title { text-align: center; margin-bottom: 44px; }
.section-title h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); }
.section-title .kicker {
  color: var(--teal); font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.12em; font-size: 0.78rem;
}
.section-title p { color: var(--text-muted); max-width: 620px; margin: 8px auto 0; }
.alt-bg { background: var(--bg-alt); }

/* ---------- Cards ---------- */
.grid { display: grid; gap: 22px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow); transition: transform 0.25s, box-shadow 0.25s;
}
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.card h3 { font-size: 1.05rem; margin-bottom: 8px; }
.card p { color: var(--text-muted); font-size: 0.9rem; }
.card .icon {
  width: 48px; height: 48px; border-radius: 12px; margin-bottom: 16px;
  background: linear-gradient(135deg, var(--navy), var(--teal));
  color: #fff; display: flex; align-items: center; justify-content: center; font-size: 1.3rem;
}

.tag {
  display: inline-block; padding: 4px 12px; border-radius: 999px; font-size: 0.74rem;
  background: rgba(0, 168, 168, 0.1); color: var(--teal-dark); font-weight: 600;
  margin: 3px 3px 3px 0; border: 1px solid rgba(0, 168, 168, 0.25);
}
[data-theme="dark"] .tag { color: var(--teal-light); }
.tag.navy { background: rgba(10, 61, 98, 0.08); color: var(--navy); border-color: rgba(10, 61, 98, 0.2); }
[data-theme="dark"] .tag.navy { color: #9FC3E0; background: rgba(27, 94, 140, 0.25); border-color: rgba(27, 94, 140, 0.5); }

.badge-status {
  display: inline-block; padding: 4px 12px; border-radius: 999px; font-size: 0.74rem; font-weight: 700;
}
.badge-granted { background: rgba(34, 160, 90, 0.14); color: #1E8E54; }
.badge-pending { background: rgba(220, 160, 20, 0.16); color: #B07E0A; }
.badge-published { background: rgba(0, 168, 168, 0.14); color: var(--teal-dark); }
[data-theme="dark"] .badge-granted { color: #5AD79B; }
[data-theme="dark"] .badge-pending { color: #E8B93E; }
[data-theme="dark"] .badge-published { color: var(--teal-light); }

/* ---------- Stats ---------- */
.stats {
  background: linear-gradient(135deg, var(--navy-dark), var(--navy));
  color: #fff; border-radius: var(--radius); padding: 44px 30px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; text-align: center;
}
.stats .num { font-family: var(--font-head); font-size: 2.2rem; font-weight: 700; color: var(--teal-light); }
.stats .label { font-size: 0.85rem; color: rgba(255, 255, 255, 0.8); }

/* ---------- Timeline ---------- */
.timeline { position: relative; margin-left: 14px; padding-left: 34px; border-left: 2px solid var(--teal); }
.timeline-item { position: relative; margin-bottom: 38px; }
.timeline-item::before {
  content: ""; position: absolute; left: -43px; top: 6px; width: 16px; height: 16px;
  border-radius: 50%; background: var(--teal); border: 3px solid var(--bg); box-shadow: 0 0 0 2px var(--teal);
}
.timeline-item .period {
  display: inline-block; font-size: 0.76rem; font-weight: 700; color: var(--teal-dark);
  background: rgba(0, 168, 168, 0.1); padding: 3px 12px; border-radius: 999px; margin-bottom: 8px;
}
[data-theme="dark"] .timeline-item .period { color: var(--teal-light); }
.timeline-item h3 { font-size: 1.08rem; }
.timeline-item .org { color: var(--text-muted); font-weight: 600; font-size: 0.9rem; margin-bottom: 8px; }
.timeline-item ul { margin: 10px 0 0 18px; color: var(--text-muted); font-size: 0.9rem; }
.timeline-item ul li { margin-bottom: 5px; }

/* ---------- Skill bars ---------- */
.skill-bar { margin-bottom: 20px; }
.skill-bar .skill-head { display: flex; justify-content: space-between; font-size: 0.88rem; font-weight: 600; margin-bottom: 7px; }
.skill-bar .track { height: 9px; border-radius: 999px; background: var(--border); overflow: hidden; }
.skill-bar .fill {
  height: 100%; width: 0; border-radius: 999px;
  background: linear-gradient(90deg, var(--navy), var(--teal));
  transition: width 1.3s cubic-bezier(0.25, 1, 0.4, 1);
}

/* ---------- Filters / search ---------- */
.toolbar { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; margin-bottom: 30px; }
.toolbar input[type="search"], .toolbar select {
  padding: 11px 16px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--card); color: var(--text); font-family: var(--font-body); font-size: 0.9rem;
  outline: none; min-width: 200px;
}
.toolbar input[type="search"]:focus, .toolbar select:focus { border-color: var(--teal); }
.chip {
  padding: 8px 16px; border-radius: 999px; border: 1px solid var(--border); background: var(--card);
  color: var(--text-muted); font-size: 0.82rem; font-weight: 600; cursor: pointer; transition: all 0.2s;
}
.chip:hover { border-color: var(--teal); color: var(--teal); }
.chip.active { background: var(--teal); border-color: var(--teal); color: #fff; }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group.full { grid-column: 1 / -1; }
.form-group label { font-size: 0.84rem; font-weight: 600; }
.form-group input, .form-group textarea, .form-group select {
  padding: 12px 14px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); font-family: var(--font-body); font-size: 0.92rem; outline: none;
}
.form-group input:focus, .form-group textarea:focus { border-color: var(--teal); }

/* ---------- Footer ---------- */
footer { background: var(--navy-dark); color: rgba(255, 255, 255, 0.8); margin-top: 40px; }
.footer-grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 36px; padding: 56px 0 40px;
}
footer h4 { color: #fff; font-size: 1rem; margin-bottom: 14px; }
footer ul { list-style: none; }
footer ul li { margin-bottom: 8px; }
footer a { color: rgba(255, 255, 255, 0.75); font-size: 0.88rem; }
footer a:hover { color: var(--teal-light); }
.footer-social { display: flex; gap: 10px; margin-top: 14px; }
.footer-social a {
  width: 38px; height: 38px; border-radius: 10px; background: rgba(255, 255, 255, 0.1);
  display: flex; align-items: center; justify-content: center; font-size: 1rem;
}
.footer-social a:hover { background: var(--teal); color: #fff; }
.newsletter { display: flex; gap: 8px; margin-top: 12px; }
.newsletter input {
  flex: 1; padding: 11px 14px; border-radius: 10px; border: none; outline: none;
  background: rgba(255, 255, 255, 0.12); color: #fff; font-family: var(--font-body);
}
.newsletter input::placeholder { color: rgba(255, 255, 255, 0.5); }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.12); padding: 18px 0; text-align: center;
  font-size: 0.82rem; color: rgba(255, 255, 255, 0.55);
}

/* ---------- Back to top ---------- */
#backTop {
  position: fixed; right: 22px; bottom: 22px; width: 46px; height: 46px; border-radius: 12px;
  background: var(--teal); color: #fff; border: none; font-size: 1.1rem; cursor: pointer;
  opacity: 0; pointer-events: none; transition: opacity 0.3s, transform 0.3s; z-index: 900;
  box-shadow: var(--shadow-lg);
}
#backTop.show { opacity: 1; pointer-events: auto; }
#backTop:hover { transform: translateY(-3px); }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ---------- Misc ---------- */
.meta { color: var(--text-muted); font-size: 0.82rem; }
.divider { height: 1px; background: var(--border); margin: 22px 0; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.list-check { list-style: none; }
.list-check li { padding-left: 28px; position: relative; margin-bottom: 10px; color: var(--text-muted); font-size: 0.92rem; }
.list-check li::before { content: "✔"; position: absolute; left: 0; color: var(--teal); font-weight: 700; }

/* ---------- Responsive ---------- */
@media (max-width: 992px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero p.summary { margin-inline: auto; }
  .btn-row { justify-content: center; }
  .nav-links {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    background: var(--card); border-bottom: 1px solid var(--border);
    flex-direction: column; padding: 12px 20px; box-shadow: var(--shadow-lg);
  }
  .nav-links.open { display: flex; }
  .hamburger { display: block; }
}
@media (max-width: 640px) {
  .grid-2, .grid-3, .grid-4, .form-grid, .two-col { grid-template-columns: 1fr; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  section { padding: 52px 0; }
  .hero { padding: 64px 0; }
  .hero-photo { width: 200px; height: 200px; font-size: 3.4rem; }
}