/* ═══════════════════════════════════════════════════════════
   DR. SANTOSH KUMAR — ACADEMIC PORTFOLIO STYLESHEET
   Clean, Editorial, High-Performance Multi-Page Architecture
   ═══════════════════════════════════════════════════════════ */

:root {
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;

  --ink-900: #0e1713;
  --ink-800: #1b2822;
  --ink-700: #2d3e35;
  --ink-600: #495e53;
  --ink-400: #7b9185;
  --ink-200: #d6e2db;

  --bg-page: #fbfbfa;
  --bg-surface: #f4f3ef;
  --bg-card: #ffffff;

  --accent: #13623f;
  --accent-hover: #0c432a;
  --accent-light: #eaf5ee;
  --accent-bright: #20b86a;

  --gold: #b38e3a;
  --gold-light: #faf5e6;

  --border: rgba(14, 23, 19, 0.08);
  --border-strong: rgba(14, 23, 19, 0.16);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;
  --radius-pill: 9999px;

  --shadow-subtle: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-card: 0 10px 30px rgba(14, 23, 19, 0.06);
  --shadow-hover: 0 18px 48px rgba(14, 23, 19, 0.11);

  --max-w: 1200px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg-page);
  color: var(--ink-800);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

.wrap {
  width: min(var(--max-w), calc(100% - 48px));
  margin-inline: auto;
}

/* ═══════════════════════════════════════════════════════════
   HEADER & NAVIGATION BAR
   ═══════════════════════════════════════════════════════════ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(251, 251, 250, 0.94);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  transition: all 0.3s ease;
}
.header-inner {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand-link {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}
.brand-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent-bright);
  box-shadow: 0 0 10px rgba(32, 184, 106, 0.6);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-item {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-600);
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  transition: all 0.2s ease;
}
.nav-item:hover, .nav-item.active {
  color: var(--ink-900);
  background: var(--accent-light);
}
.nav-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: var(--accent);
  color: #fff;
  padding: 9px 20px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 700;
  transition: all 0.25s ease;
  box-shadow: 0 4px 14px rgba(19, 98, 63, 0.25);
  margin-left: 10px;
}
.nav-cta-btn:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}
.mobile-toggle {
  display: none;
  font-size: 22px;
  color: var(--ink-900);
  padding: 6px;
}

/* ═══════════════════════════════════════════════════════════
   PAGE HERO / BANNER (FOR INNER PAGES)
   ═══════════════════════════════════════════════════════════ */
.page-hero {
  padding: 56px 0 36px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-surface);
}
.page-kicker {
  font-size: 11.5px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.page-kicker::before {
  content: ""; width: 14px; height: 2px; background: var(--accent);
}
.page-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(32px, 4.2vw, 48px);
  font-weight: 700;
  color: var(--ink-900);
  line-height: 1.15;
  margin-bottom: 10px;
}
.page-hero p {
  font-size: 16px;
  color: var(--ink-600);
  max-width: 720px;
}

/* ═══════════════════════════════════════════════════════════
   AUTO-MOVING MARQUEE (AWARDS & PARTNERSHIPS)
   ═══════════════════════════════════════════════════════════ */
.marquee-wrapper {
  overflow: hidden;
  user-select: none;
  padding: 16px 0;
  position: relative;
}
.marquee-wrapper::before, .marquee-wrapper::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0;
  width: 60px;
  z-index: 2;
  pointer-events: none;
}
.marquee-wrapper::before {
  left: 0;
  background: linear-gradient(to right, var(--bg-page), transparent);
}
.marquee-wrapper::after {
  right: 0;
  background: linear-gradient(to left, var(--bg-page), transparent);
}
.marquee-content {
  display: flex;
  gap: 20px;
  width: max-content;
  animation: scrollMarquee 38s linear infinite;
}
.marquee-wrapper:hover .marquee-content {
  animation-play-state: paused;
}
@keyframes scrollMarquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ═══════════════════════════════════════════════════════════
   PRESTIGIOUS ACADEMIC SHOWCASE CARDS (PUBLICATIONS & AWARDS)
   ═══════════════════════════════════════════════════════════ */

/* 1. Landmark Selected Publications Grid */
.landmark-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
  margin-bottom: 36px;
}
.landmark-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 26px 28px;
  box-shadow: var(--shadow-subtle);
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
}
.landmark-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow-card);
}
.landmark-badge-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}
.landmark-badge {
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  background: var(--accent-light);
  padding: 4px 10px;
  border-radius: var(--radius-pill);
}
.landmark-if {
  font-size: 11.5px;
  font-weight: 700;
  color: var(--ink-700);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: 3px 9px;
  border-radius: var(--radius-pill);
}
.landmark-title {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  color: var(--ink-900);
  line-height: 1.42;
  margin-bottom: 10px;
}
.landmark-journal {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-700);
  margin-bottom: 6px;
}
.landmark-authors {
  font-size: 12.5px;
  color: var(--ink-500);
  margin-bottom: 16px;
  line-height: 1.5;
}
.landmark-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: auto;
  flex-wrap: wrap;
}
.landmark-btn-doi {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12.5px;
  font-weight: 700;
  color: #fff;
  background: var(--ink-900);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  transition: all 0.2s ease;
}
.landmark-btn-doi:hover {
  background: var(--accent);
  color: #07150e;
  transform: translateY(-1px);
}
.landmark-btn-preview {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--accent);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all 0.2s ease;
}
.landmark-btn-preview:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

/* ═══════════════════════════════════════════════════════════
   DOCUMENT FIRST-PAGE & CERTIFICATE CARDS (USER PREFERRED SIZE)
   ═══════════════════════════════════════════════════════════ */

/* Publication First-Page Cards (Exact 210px wide x 275px document image matching user screenshot) */
.marquee-doc-card,
.pub-cover-card {
  flex: 0 0 210px !important;
  width: 210px !important;
  max-width: 210px !important;
  background: var(--bg-card, #fff) !important;
  border: 1px solid rgba(0,0,0,0.1) !important;
  border-radius: 14px !important;
  overflow: hidden !important;
  box-shadow: 0 4px 16px rgba(0,0,0,0.06) !important;
  cursor: pointer !important;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease !important;
  display: flex !important;
  flex-direction: column !important;
  text-decoration: none !important;
}
.marquee-doc-card:hover,
.pub-cover-card:hover {
  transform: translateY(-6px) !important;
  border-color: var(--accent, #22C06E) !important;
  box-shadow: 0 12px 28px rgba(0,0,0,0.14) !important;
}
.marquee-doc-thumb,
.pub-cover-thumb {
  width: 210px !important;
  height: 275px !important;
  max-width: 210px !important;
  max-height: 275px !important;
  overflow: hidden !important;
  background: #fff !important;
  position: relative !important;
}
.marquee-doc-thumb img,
.pub-cover-thumb img {
  width: 210px !important;
  height: 275px !important;
  max-width: 210px !important;
  max-height: 275px !important;
  object-fit: cover !important;
  object-position: top center !important;
  display: block !important;
  transition: transform 0.35s ease !important;
}
.marquee-doc-card:hover .marquee-doc-thumb img,
.pub-cover-card:hover .pub-cover-thumb img {
  transform: scale(1.03) !important;
}
.marquee-doc-label,
.pub-cover-info {
  padding: 12px 14px !important;
  background: var(--bg-surface, #f9fafb) !important;
  border-top: 1px solid rgba(0,0,0,0.06) !important;
  text-align: center !important;
  display: flex !important;
  flex-direction: column !important;
  justify-content: center !important;
}
.pub-cover-journal {
  font-size: 12.5px !important;
  font-weight: 750 !important;
  color: var(--ink-900, #111) !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
  line-height: 1.3 !important;
}
.pub-cover-meta {
  font-size: 11px !important;
  color: var(--accent, #22C06E) !important;
  font-weight: 700 !important;
  margin-top: 3px !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
}

/* Award Certificate Cards (Exact 340px wide x 225px certificate image) */
.marquee-cert-card,
.award-cert-card {
  flex: 0 0 340px !important;
  width: 340px !important;
  max-width: 340px !important;
  background: var(--bg-card, #fff) !important;
  border: 1px solid rgba(0,0,0,0.1) !important;
  border-radius: 14px !important;
  overflow: hidden !important;
  box-shadow: 0 4px 16px rgba(0,0,0,0.06) !important;
  cursor: pointer !important;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease !important;
  display: flex !important;
  flex-direction: column !important;
  text-decoration: none !important;
}
.marquee-cert-card:hover,
.award-cert-card:hover {
  transform: translateY(-6px) !important;
  border-color: var(--accent, #22C06E) !important;
  box-shadow: 0 12px 28px rgba(0,0,0,0.14) !important;
}
.marquee-cert-thumb,
.award-cert-thumb {
  width: 340px !important;
  height: 225px !important;
  max-width: 340px !important;
  max-height: 225px !important;
  overflow: hidden !important;
  background: #f7f9f8 !important;
  position: relative !important;
}
.marquee-cert-thumb img,
.award-cert-thumb img {
  width: 340px !important;
  height: 225px !important;
  max-width: 340px !important;
  max-height: 225px !important;
  object-fit: cover !important;
  object-position: center top !important;
  display: block !important;
  transition: transform 0.35s ease !important;
}
.marquee-cert-card:hover .marquee-cert-thumb img,
.award-cert-card:hover .award-cert-thumb img {
  transform: scale(1.03) !important;
}
.award-cert-zoom {
  position: absolute !important;
  bottom: 10px !important;
  right: 10px !important;
  background: rgba(14, 23, 19, 0.85) !important;
  backdrop-filter: blur(6px) !important;
  color: #fff !important;
  padding: 5px 12px !important;
  border-radius: 9999px !important;
  font-size: 11px !important;
  font-weight: 700 !important;
  display: flex !important;
  align-items: center !important;
  gap: 5px !important;
  opacity: 0 !important;
  transition: opacity 0.2s ease !important;
}
.award-cert-card:hover .award-cert-zoom,
.marquee-cert-card:hover .award-cert-zoom {
  opacity: 1 !important;
}
.marquee-cert-label,
.award-cert-body {
  padding: 14px 18px !important;
  background: var(--bg-surface, #f9fafb) !important;
  border-top: 1px solid rgba(0,0,0,0.06) !important;
}
.award-cert-tag {
  font-size: 10.5px !important;
  font-weight: 800 !important;
  text-transform: uppercase !important;
  color: var(--accent, #22C06E) !important;
  letter-spacing: 0.08em !important;
  margin-bottom: 4px !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
}
.marquee-cert-title,
.award-cert-title {
  font-size: 14px !important;
  font-weight: 750 !important;
  color: var(--ink-900, #111) !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
  line-height: 1.35 !important;
}
.marquee-cert-sub,
.award-cert-inst {
  font-size: 11.5px !important;
  color: var(--ink-500, #666) !important;
  font-weight: 500 !important;
  margin-top: 3px !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
}

/* Document & Award Marquee Section Frame */
.doc-marquee-section {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px 0 36px;
  box-shadow: var(--shadow-subtle);
  overflow: hidden;
}
.doc-marquee-section .marquee-wrapper::before {
  background: linear-gradient(to right, var(--bg-surface), transparent) !important;
}
.doc-marquee-section .marquee-wrapper::after {
  background: linear-gradient(to left, var(--bg-surface), transparent) !important;
}

/* ═══════════════════════════════════════════════════════════
   BUTTONS & CARDS
   ═══════════════════════════════════════════════════════════ */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--ink-900);
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius-pill);
  font-size: 13.5px;
  font-weight: 700;
  transition: all 0.25s ease;
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}
.btn-primary:hover {
  background: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(19, 98, 63, 0.3);
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  color: var(--ink-800);
  border: 1.5px solid var(--border);
  padding: 11px 22px;
  border-radius: var(--radius-pill);
  font-size: 13.5px;
  font-weight: 700;
  transition: all 0.25s ease;
}
.btn-secondary:hover {
  border-color: var(--ink-900);
  transform: translateY(-2px);
  box-shadow: var(--shadow-subtle);
}

/* Academic Pill Buttons */
.profile-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 14px;
  background: var(--bg-card);
  color: var(--ink-800);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-size: 12.5px;
  font-weight: 700;
  transition: all 0.25s ease;
}
.profile-pill:hover {
  background: var(--ink-900);
  color: #fff;
  border-color: var(--ink-900);
  transform: translateY(-2px);
  box-shadow: 0 4px 14px rgba(0,0,0,0.12);
}
.profile-pill svg { width: 15px; height: 15px; flex-shrink: 0; }

/* ═══════════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════════ */
.site-footer {
  margin-top: auto;
  background: var(--ink-900);
  color: #c0d3c9;
  padding: 56px 0 32px;
  border-top: 1px solid rgba(255,255,255,0.08);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-col h4 {
  font-size: 14px;
  font-weight: 750;
  color: #fff;
  margin-bottom: 16px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.footer-col p { font-size: 13.5px; line-height: 1.7; color: #a4bab0; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 8px; font-size: 13.5px; }
.footer-links a:hover { color: #fff; text-decoration: underline; }
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  font-size: 12.5px;
  color: #7b968a;
}
.footer-bottom a { color: #a4bab0; text-decoration: underline; margin-left: 6px; }

/* ═══════════════════════════════════════════════════════════
   LIGHTBOX MODAL
   ═══════════════════════════════════════════════════════════ */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 5000;
  background: rgba(10, 20, 16, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.lightbox.active { display: flex; }
.lightbox-card {
  position: relative;
  max-width: 92vw;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.lightbox-card img {
  max-width: 90vw;
  max-height: 78vh;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 24px 60px rgba(0,0,0,0.6);
}
.lightbox-caption {
  color: #fff;
  font-size: 14px;
  margin-top: 14px;
  text-align: center;
  max-width: 720px;
  line-height: 1.5;
}
.lightbox-close {
  position: absolute;
  top: -44px; right: -8px;
  width: 36px; height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  color: #fff;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}
.lightbox-close:hover { background: rgba(255,255,255,0.35); }

/* ═══════════════════════════════════════════════════════════
   RESPONSIVE DESIGN
   ═══════════════════════════════════════════════════════════ */
@media (max-width: 900px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 72px; left: 16px; right: 16px;
    background: #fff;
    border-radius: 18px;
    padding: 16px;
    box-shadow: 0 16px 40px rgba(0,0,0,0.15);
    border: 1px solid var(--border);
    flex-direction: column;
    align-items: stretch;
  }
  .nav-links.open { display: flex; }
  .mobile-toggle { display: block; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
}