/* ==========================================================================
   NextGen Scholars — Design System
   Professional education / research publishing platform
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Figtree:ital,wght@0,400;0,500;0,600;0,700;0,800;1,400&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;0,6..72,700;1,6..72,400&display=swap');

:root {
  /* Color — ink, paper, single accent */
  --ink: #0c1220;
  --ink-soft: #1a2332;
  --ink-muted: #3d4a5c;
  --text: #15202b;
  --text-muted: #5a6577;
  --text-faint: #8b95a5;
  --paper: #ffffff;
  --surface: #f5f7fa;
  --surface-2: #eef1f6;
  --border: #dde3ec;
  --border-strong: #c5cedb;
  --accent: #0f6e6e;
  --accent-hover: #0a5555;
  --accent-soft: #e6f3f3;
  --accent-on: #ffffff;
  --focus: #0f6e6e;
  --danger: #b42318;
  --success: #067647;

  /* Cover tones for paper cards (no emoji) */
  --cover-1: #0f6e6e;
  --cover-2: #1a365d;
  --cover-3: #2c5282;
  --cover-4: #234e52;
  --cover-5: #44337a;
  --cover-6: #744210;

  /* Typography */
  --font-sans: 'Figtree', system-ui, sans-serif;
  --font-serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --fs-xs: 0.8125rem;
  --fs-sm: 0.9375rem;
  --fs-base: 1.0625rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 1.875rem;
  --fs-3xl: 2.5rem;
  --fs-4xl: clamp(2.75rem, 5vw, 3.75rem);
  --fs-hero: clamp(2.75rem, 6vw, 4.25rem);
  --lh-tight: 1.15;
  --lh-snug: 1.35;
  --lh-body: 1.7;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --space-9: 6rem;
  --container: 1120px;
  --container-wide: 1280px;
  --header-h: 72px;
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(12, 18, 32, 0.06);
  --shadow: 0 4px 16px rgba(12, 18, 32, 0.08);
  --shadow-lg: 0 12px 40px rgba(12, 18, 32, 0.12);
  --shadow-lift: 0 16px 48px rgba(12, 18, 32, 0.16);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --transition: 0.25s var(--ease);
}

/* Reset ------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent-hover); }
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: var(--lh-tight);
  color: var(--ink);
  margin: 0 0 var(--space-4);
}
p { margin: 0 0 var(--space-4); }
button, input, select, textarea { font: inherit; }

/* Focus ------------------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

/* Layout ------------------------------------------------------------------ */
.container {
  width: min(100% - 2.5rem, var(--container));
  margin-inline: auto;
}
.container-wide {
  width: min(100% - 2.5rem, var(--container-wide));
  margin-inline: auto;
}
.page-main {
  padding-top: var(--header-h);
  min-height: 60vh;
}
.section {
  padding: var(--space-8) 0;
}
.section--surface { background: var(--surface); }
.section--ink {
  background: var(--ink);
  color: #e8ecf2;
}
.section--ink h2, .section--ink h3 { color: #fff; }
.section-label {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--space-3);
}
.section-title {
  font-size: var(--fs-3xl);
  margin-bottom: var(--space-3);
}
.section-lead {
  font-size: var(--fs-md);
  color: var(--text-muted);
  max-width: 42rem;
  margin-bottom: 0;
}

/* Header / Nav ------------------------------------------------------------ */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-h);
  z-index: 1100;
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition), box-shadow var(--transition);
}
.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-sm);
}
.site-header__inner {
  width: 100%;
  padding-inline: clamp(1rem, 2vw, 1.75rem);
  box-sizing: border-box;
  margin-inline: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--ink);
  flex-shrink: 0;
}
.site-logo__text {
  display: flex;
  align-items: baseline;
  gap: 0.32em;
  line-height: 1;
  font-family: var(--font-serif);
  font-size: 2.5rem;
  white-space: nowrap;
}
.site-logo__name {
  font-family: var(--font-serif);
  font-size: 1em;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.025em;
}
.site-logo__tag {
  font-family: var(--font-serif);
  font-size: 1em;
  font-style: italic;
  font-weight: 500;
  letter-spacing: -0.01em;
  text-transform: none;
  color: var(--accent);
}
@media (max-width: 1100px) {
  .site-logo__text { font-size: 2.1rem; }
}
@media (max-width: 520px) {
  .site-logo__text { font-size: 1.7rem; }
}
.site-nav {
  display: none;
  align-items: center;
  gap: 0.15rem;
}
.site-nav a:not(.btn) {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 0.55rem 0.9rem;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--ink-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.site-nav a:not(.btn):hover {
  color: var(--ink);
  background: var(--surface);
}
.site-nav a:not(.btn).is-active {
  color: var(--ink);
}
.site-nav a:not(.btn).is-active::after {
  content: '';
  position: absolute;
  left: 0.9rem;
  right: 0.9rem;
  bottom: 0.25rem;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}
.site-nav__cta {
  margin-left: var(--space-3);
  color: var(--accent-on);
}
.site-nav a.btn--primary,
.site-nav a.site-nav__cta {
  color: var(--accent-on);
}
.site-nav a.btn--primary:hover,
.site-nav a.site-nav__cta:hover {
  color: var(--accent-on);
  background: var(--accent-hover);
}
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}
.nav-toggle:hover {
  border-color: var(--border-strong);
  background: var(--surface);
}
.nav-toggle svg { width: 22px; height: 22px; }

@media (min-width: 960px) {
  .site-nav { display: flex; }
  .nav-toggle { display: none; }
}

/* Mobile drawer ----------------------------------------------------------- */
.nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: min(320px, 88vw);
  height: 100%;
  background: var(--ink);
  color: #fff;
  z-index: 1200;
  padding: calc(var(--header-h) + 1rem) 0 2rem;
  transform: translateX(100%);
  transition: transform 0.35s var(--ease);
  box-shadow: var(--shadow-lg);
}
.nav-drawer.is-open { transform: translateX(0); }
.nav-drawer a {
  display: block;
  padding: 0.95rem 1.75rem;
  color: rgba(255, 255, 255, 0.88);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--fs-md);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background var(--transition), color var(--transition), padding-left var(--transition);
}
.nav-drawer a:hover,
.nav-drawer a.is-active {
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  padding-left: 2rem;
}
.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(12, 18, 32, 0.5);
  z-index: 1150;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s var(--ease), visibility 0.3s;
}
.nav-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

/* Buttons ----------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 48px;
  padding: 0.75rem 1.35rem;
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  font-weight: 700;
  line-height: 1;
  border-radius: var(--radius-sm);
  border: 1.5px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn--primary {
  background: var(--accent);
  color: var(--accent-on);
}
.btn--primary:hover {
  background: var(--accent-hover);
  color: var(--accent-on);
  box-shadow: var(--shadow);
}
.btn--secondary {
  background: transparent;
  color: var(--ink);
  border-color: var(--border-strong);
}
.btn--secondary:hover {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--ink-muted);
}
.btn--ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.45);
}
.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border-color: #fff;
}
.btn--on-dark {
  background: #fff;
  color: var(--ink);
}
.btn--on-dark:hover {
  background: var(--surface-2);
  color: var(--ink);
}
.btn--lg {
  min-height: 54px;
  padding: 0.9rem 1.6rem;
  font-size: var(--fs-base);
}
.btn--sm {
  min-height: 40px;
  padding: 0.5rem 1rem;
  font-size: var(--fs-xs);
}

/* Forms ------------------------------------------------------------------- */
.form-label {
  display: block;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--space-2);
}
.form-input,
.form-select,
.form-textarea {
  width: 100%;
  min-height: 48px;
  padding: 0.7rem 0.95rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--paper);
  color: var(--text);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.form-textarea { min-height: 140px; resize: vertical; }
.form-input:hover,
.form-select:hover,
.form-textarea:hover { border-color: var(--border-strong); }
.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.form-input::placeholder,
.form-textarea::placeholder { color: var(--text-faint); }

/* Badges ------------------------------------------------------------------ */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.65rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  border-radius: 4px;
  background: var(--accent-soft);
  color: var(--accent);
}
.badge--ink {
  background: var(--ink);
  color: #fff;
}
.badge--muted {
  background: var(--surface-2);
  color: var(--ink-muted);
}

/* Cards (interaction containers only) ------------------------------------- */
.card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.card--interactive:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
  border-color: var(--border-strong);
}

/* Footer ------------------------------------------------------------------ */
.site-footer {
  background: var(--ink);
  color: rgba(255, 255, 255, 0.78);
  padding: var(--space-8) 0 var(--space-6);
  margin-top: auto;
}
.site-footer a {
  color: rgba(255, 255, 255, 0.78);
  text-decoration: none;
}
.site-footer a:hover { color: #fff; }
.footer-grid {
  display: grid;
  gap: var(--space-7);
  grid-template-columns: 1fr;
}
@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr;
  }
}
.footer-brand__name {
  font-family: var(--font-serif);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-3);
}
.footer-brand p {
  max-width: 28rem;
  font-size: var(--fs-sm);
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.65);
}
.footer-col h4 {
  font-family: var(--font-sans);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.45);
  margin-bottom: var(--space-4);
}
.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.65rem;
}
.footer-col a {
  font-size: var(--fs-sm);
  font-weight: 500;
}
.footer-subscribe {
  margin-top: var(--space-4);
  display: grid;
  gap: var(--space-3);
}
.footer-subscribe .form-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.footer-subscribe .form-input {
  flex: 1 1 140px;
  min-height: 44px;
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.15);
  color: #fff;
}
.footer-subscribe .form-input::placeholder { color: rgba(255, 255, 255, 0.4); }
.footer-bottom {
  margin-top: var(--space-7);
  padding-top: var(--space-5);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-3);
  font-size: var(--fs-xs);
  color: rgba(255, 255, 255, 0.45);
}

/* Utilities --------------------------------------------------------------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.mx-auto { margin-inline: auto; }
.stack-sm > * + * { margin-top: var(--space-3); }
.stack > * + * { margin-top: var(--space-5); }
.stack-lg > * + * { margin-top: var(--space-7); }

/* Motion ------------------------------------------------------------------ */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}
.animate-fade-up {
  animation: fade-up 0.8s var(--ease) both;
}
.animate-fade-up-delay {
  animation: fade-up 0.8s var(--ease) 0.15s both;
}
.animate-fade-up-delay-2 {
  animation: fade-up 0.8s var(--ease) 0.3s both;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}