/* Shared components for every page. Load after tokens.css and before the page stylesheet. */

/* === SKIP LINK === */
.skip-link {
  position: absolute;
  left: var(--s-4);
  top: -100px;
  z-index: 100;
  padding: var(--s-2) var(--s-4);
  background: var(--page);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
}
.skip-link:focus {
  top: var(--s-2);
}

/* === TOP NAV === */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--nav-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-5);
  min-height: var(--nav-h);
}
.nav-brand {
  color: var(--ink);
  font-weight: 700;
  font-size: var(--fs-md);
  white-space: nowrap;
}
.nav-brand:hover {
  color: var(--ink);
  text-decoration: none;
}
/* The Bengali name stays in the page heading; the bar has no room for it. */
.nav-brand-alt {
  display: none;
}
.nav-inner > nav {
  min-width: 0;
}
.nav-links {
  display: flex;
  gap: var(--s-4);
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.nav-links::-webkit-scrollbar {
  display: none;
}
.nav-links.is-scrollable {
  mask-image: linear-gradient(to right, #000 85%, transparent);
  -webkit-mask-image: linear-gradient(to right, #000 85%, transparent);
}
.nav-links a {
  display: block;
  color: var(--muted);
  font-size: var(--fs-sm);
  font-weight: 500;
  white-space: nowrap;
  padding: var(--s-1) 0;
  border-bottom: 2px solid transparent;
}
.nav-links a:hover {
  color: var(--ink);
  text-decoration: none;
  border-bottom-color: var(--line);
}
.nav-links a.active {
  color: var(--ink);
  font-weight: 600;
  border-bottom-color: var(--link);
}
.nav-controls {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  flex-shrink: 0;
}

/* === BUTTONS === */
.btn,
.cv-download,
.theme-toggle,
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  flex-shrink: 0;
  min-height: 36px;
  padding: 0 var(--s-3);
  font: inherit;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--ink);
  background: var(--page);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  cursor: pointer;
  white-space: nowrap;
}
.btn:hover,
.cv-download:hover,
.theme-toggle:hover,
.nav-toggle:hover {
  color: var(--ink);
  background: var(--surface);
  border-color: var(--rule);
  text-decoration: none;
}
.btn:disabled,
.cv-download:disabled {
  opacity: 0.6;
  cursor: progress;
}
.btn svg,
.cv-download svg {
  display: block;
  width: 16px;
  height: 16px;
}
.btn-icon,
.theme-toggle,
.nav-toggle {
  width: 36px;
  padding: 0;
}
.btn-sm {
  min-height: 28px;
  padding: 0 var(--s-2);
  font-size: var(--fs-xs);
  color: var(--link);
}
.btn-sm:hover {
  color: var(--link-dark);
}
.btn-primary {
  min-height: 44px;
  padding: 0 var(--s-4);
  background: var(--link);
  border-color: var(--link);
  color: var(--on-link);
  font-weight: 600;
}
.btn-primary:hover {
  background: var(--link-dark);
  border-color: var(--link-dark);
  color: var(--on-link);
}

.theme-toggle svg {
  display: block;
  width: 18px;
  height: 18px;
}
.theme-toggle .icon-sun {
  display: none;
}
:root[data-theme="dark"] .theme-toggle .icon-sun {
  display: block;
}
:root[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

/* Hamburger: hidden on wide screens, bars turn into an X while open */
.nav-toggle {
  display: none;
}
.nav-toggle-bars,
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s ease, background 0.2s ease;
}
.nav-toggle-bars {
  position: relative;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
}
.nav-toggle-bars::before {
  top: -6px;
}
.nav-toggle-bars::after {
  top: 6px;
}
.site-nav.menu-open .nav-toggle-bars {
  background: transparent;
}
.site-nav.menu-open .nav-toggle-bars::before {
  transform: translateY(6px) rotate(45deg);
}
.site-nav.menu-open .nav-toggle-bars::after {
  transform: translateY(-6px) rotate(-45deg);
}

/* === CHIP, EYEBROW, BADGE, CARD === */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--fs-xs);
  line-height: 1.5;
  padding: 2px var(--s-2);
  color: var(--body);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
}
a.chip,
button.chip {
  min-height: 40px;
  padding: 0 var(--s-3);
  font-family: inherit;
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--ink);
  background: var(--page);
  border-radius: var(--r-md);
  cursor: pointer;
}
a.chip:hover,
button.chip:hover {
  text-decoration: none;
  border-color: var(--rule);
  background: var(--surface);
}
button.chip[aria-pressed="true"] {
  background: var(--link);
  border-color: var(--link);
  color: var(--on-link);
}
a.chip i {
  color: var(--muted);
}

.eyebrow {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--link-dark);
}
.eyebrow.filled {
  background: var(--link-soft);
  padding: 1px var(--s-2);
  border-radius: var(--r-sm);
}
.eyebrow.quiet {
  color: var(--muted);
}

.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 1px 6px;
  border-radius: var(--r-sm);
  margin-right: 6px;
  vertical-align: 1px;
}
.badge-paper {
  background: var(--badge-paper-bg);
  color: var(--badge-paper-fg);
}
.badge-award {
  background: var(--badge-award-bg);
  color: var(--badge-award-fg);
}
.badge-review {
  background: var(--badge-review-bg);
  color: var(--badge-review-fg);
}
.badge-edu {
  background: var(--badge-edu-bg);
  color: var(--badge-edu-fg);
}

.card {
  background: var(--page);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: var(--s-4);
}
a.card {
  display: block;
  color: inherit;
  transition: border-color 0.15s, box-shadow 0.15s;
}
a.card:hover {
  text-decoration: none;
  border-color: var(--rule);
  box-shadow: var(--shadow);
}

/* === SECTION HEAD === */
.section-title {
  font-size: var(--fs-xl);
  font-weight: 700;
}
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s-1) var(--s-4);
  padding-bottom: var(--s-2);
  margin-bottom: var(--s-4);
  border-bottom: 1px solid var(--line);
}
.section-head-links {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--s-1) var(--s-4);
  font-size: var(--fs-sm);
}

/* === FOOTER === */
.site-footer {
  margin-top: var(--s-8);
  border-top: 1px solid var(--line);
}
.site-copyright {
  color: var(--muted);
  font-size: var(--fs-xs);
  text-align: center;
  padding: var(--s-5) 0;
}

/* === SMALL SCREENS: nav becomes a drawer === */
@media (max-width: 820px) {
  .nav-toggle {
    display: inline-flex;
  }
  .site-nav .nav-inner > nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    border-bottom: 1px solid var(--line);
    background: var(--page);
    box-shadow: var(--shadow);
  }
  .site-nav.menu-open .nav-inner > nav {
    display: block;
  }
  .site-nav .nav-links,
  .site-nav .nav-links.is-scrollable {
    flex-direction: column;
    gap: 0;
    padding: var(--s-1) var(--s-5) var(--s-3);
    overflow: visible;
    mask-image: none;
    -webkit-mask-image: none;
  }
  .site-nav .nav-links a {
    padding: var(--s-3) 0;
    border-bottom: 1px solid var(--line);
    font-size: var(--fs-md);
  }
  .site-nav .nav-links li:last-child a {
    border-bottom: 0;
  }
  .site-nav .nav-links a:hover,
  .site-nav .nav-links a.active {
    border-bottom-color: var(--line);
    color: var(--link);
  }
}

@media print {
  .theme-toggle,
  .cv-download,
  .nav-toggle,
  .skip-link {
    display: none;
  }
}