/* IEEE Journals Online — ieeejournalsonline.com */
:root {
  --navy: #0a1f3d;
  --navy-deep: #061428;
  --navy-mid: #123056;
  --blue: #1a6fd4;
  --blue-bright: #2b7de9;
  --blue-soft: #e8f1fc;
  --steel: #5c6b7a;
  --ink: #142033;
  --muted: #64748b;
  --line: rgba(10, 31, 61, 0.1);
  --paper: #f7f9fc;
  --white: #ffffff;
  --success: #0d7a4f;
  --radius: 4px;
  --shadow: 0 18px 50px rgba(6, 20, 40, 0.12);
  --font-display: "Source Serif 4", Georgia, serif;
  --font-sans: "Lexend", "Segoe UI", sans-serif;
  --max: 1120px;
  --header-h: 76px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--navy);
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  color: var(--navy);
  margin: 0 0 0.6em;
}

p {
  margin: 0 0 1em;
}

.container {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

/* ——— Header ——— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
  height: var(--header-h);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.logo-link {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.logo-link img {
  height: 48px;
  width: auto;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.45rem 0.7rem;
  cursor: pointer;
  color: var(--navy);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.15rem 1.35rem;
}

.site-nav a {
  color: var(--navy-mid);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--blue);
}

.site-nav .btn {
  margin-left: 0.5rem;
}

/* ——— Buttons ——— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.75rem 1.35rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background 0.25s ease, color 0.25s ease, border-color 0.25s ease,
    transform 0.2s ease;
  text-decoration: none;
  line-height: 1.2;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
}

.btn-primary:hover {
  background: var(--navy);
  border-color: var(--navy);
  color: var(--white);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.55);
}

.btn-outline:hover {
  background: var(--white);
  color: var(--navy);
  border-color: var(--white);
}

.btn-outline-dark {
  background: transparent;
  color: var(--navy);
  border-color: var(--navy);
}

.btn-outline-dark:hover {
  background: var(--navy);
  color: var(--white);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
}

/* ——— Hero ——— */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse 80% 60% at 70% 40%, rgba(26, 111, 212, 0.35), transparent 55%),
    radial-gradient(ellipse 50% 40% at 15% 80%, rgba(18, 48, 86, 0.5), transparent 50%),
    linear-gradient(145deg, var(--navy-deep) 0%, var(--navy) 45%, var(--navy-mid) 100%);
  color: var(--white);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 60% 50%, black, transparent);
  pointer-events: none;
  animation: grid-drift 40s linear infinite;
}

.hero::after {
  content: "";
  position: absolute;
  width: min(520px, 70vw);
  height: min(520px, 70vw);
  right: -8%;
  top: 50%;
  transform: translateY(-50%);
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow:
    0 0 0 40px rgba(255, 255, 255, 0.03),
    0 0 0 90px rgba(255, 255, 255, 0.02);
  pointer-events: none;
  animation: pulse-ring 8s ease-in-out infinite;
}

@keyframes grid-drift {
  from { background-position: 0 0; }
  to { background-position: 48px 48px; }
}

@keyframes pulse-ring {
  0%, 100% { opacity: 0.6; transform: translateY(-50%) scale(1); }
  50% { opacity: 1; transform: translateY(-50%) scale(1.04); }
}

.hero-inner {
  position: relative;
  z-index: 2;
  padding: 4.5rem 0 5rem;
  max-width: 640px;
}

.hero-brand {
  margin-bottom: 1.75rem;
  animation: rise-in 0.8s ease both;
  display: inline-flex;
  align-items: center;
  padding: 0.65rem 1rem;
  background: var(--white);
  border-radius: 6px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.2);
}

.hero-brand img {
  height: clamp(48px, 7vw, 64px);
  width: auto;
}

.hero h1 {
  color: var(--white);
  font-size: clamp(2rem, 4.5vw, 3.15rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 0.85rem;
  animation: rise-in 0.8s 0.12s ease both;
}

.hero .lead {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.78);
  max-width: 36ch;
  margin-bottom: 2rem;
  animation: rise-in 0.8s 0.24s ease both;
}

.hero .btn-group {
  animation: rise-in 0.8s 0.36s ease both;
}

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ——— Sections ——— */
.section {
  padding: 5rem 0;
}

.section-head {
  max-width: 560px;
  margin-bottom: 2.75rem;
}

.section-head h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
}

.section-head p {
  color: var(--muted);
  font-size: 1.05rem;
  margin: 0;
}

.section-alt {
  background: var(--white);
}

.section-navy {
  background: var(--navy);
  color: rgba(255, 255, 255, 0.85);
}

.section-navy h2,
.section-navy h3 {
  color: var(--white);
}

.section-navy .section-head p {
  color: rgba(255, 255, 255, 0.65);
}

/* ——— Feature rows (no cards in hero; simple list/grid elsewhere) ——— */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.5rem 2rem;
}

.feature-item {
  position: relative;
  padding-top: 1.25rem;
}

.feature-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 3px;
  background: var(--blue);
}

.feature-item h3 {
  font-size: 1.2rem;
  margin-bottom: 0.4rem;
}

.feature-item p {
  color: var(--muted);
  margin: 0;
  font-size: 0.95rem;
}

/* ——— Journal list ——— */
.journal-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--line);
}

.journal-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem 2rem;
  align-items: center;
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--line);
  transition: background 0.2s ease;
}

.journal-row:hover {
  background: rgba(26, 111, 212, 0.04);
}

.journal-row h3 {
  font-size: 1.15rem;
  margin: 0 0 0.25rem;
}

.journal-row p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.journal-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  font-size: 0.8rem;
  color: var(--steel);
  margin-top: 0.45rem;
}

.tag {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

/* ——— Stats strip ——— */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  text-align: center;
}

.stat strong {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.4rem);
  color: var(--white);
  font-weight: 600;
  line-height: 1.1;
}

.stat span {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ——— CTA band ——— */
.cta-band {
  padding: 4rem 0;
  background:
    linear-gradient(120deg, var(--navy-deep), var(--navy-mid)),
    var(--navy);
  text-align: center;
  color: var(--white);
}

.cta-band h2 {
  color: var(--white);
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  margin-bottom: 0.5rem;
}

.cta-band p {
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 1.75rem;
}

.cta-band .btn-group {
  justify-content: center;
}

/* ——— Page hero (inner pages) ——— */
.page-hero {
  background:
    linear-gradient(135deg, var(--navy-deep) 0%, var(--navy) 60%, var(--navy-mid) 100%);
  color: var(--white);
  padding: 3.5rem 0 3rem;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 0.7;
  pointer-events: none;
}

.page-hero .container {
  position: relative;
  z-index: 1;
}

.page-hero h1 {
  color: var(--white);
  font-size: clamp(1.85rem, 3.5vw, 2.5rem);
  margin-bottom: 0.4rem;
}

.page-hero p {
  color: rgba(255, 255, 255, 0.7);
  max-width: 48ch;
  margin: 0;
}

.breadcrumb {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 0.85rem;
}

.breadcrumb a {
  color: rgba(255, 255, 255, 0.7);
}

.breadcrumb a:hover {
  color: var(--white);
}

/* ——— Forms ——— */
.form-grid {
  display: grid;
  gap: 1.15rem;
  max-width: 640px;
}

.form-row-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.15rem;
}

label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 0.35rem;
}

input,
select,
textarea {
  width: 100%;
  padding: 0.75rem 0.9rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  color: var(--ink);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(26, 111, 212, 0.15);
}

textarea {
  min-height: 140px;
  resize: vertical;
}

.form-note {
  font-size: 0.85rem;
  color: var(--muted);
}

.form-success {
  display: none;
  padding: 1rem 1.25rem;
  background: rgba(13, 122, 79, 0.08);
  border-left: 3px solid var(--success);
  color: var(--success);
  font-weight: 500;
  margin-bottom: 1.25rem;
}

.form-success.show {
  display: block;
}

/* ——— Content prose ——— */
.prose {
  max-width: 720px;
}

.prose h2 {
  font-size: 1.45rem;
  margin-top: 2rem;
}

.prose h3 {
  font-size: 1.15rem;
  margin-top: 1.5rem;
}

.prose ul,
.prose ol {
  padding-left: 1.25rem;
  color: var(--ink);
}

.prose li {
  margin-bottom: 0.45rem;
}

.prose li::marker {
  color: var(--blue);
}

.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: 720px;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 0 0 2rem 3.5rem;
  border-left: 2px solid var(--line);
  margin-left: 0.85rem;
}

.steps li:last-child {
  border-left-color: transparent;
  padding-bottom: 0;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: -1.05rem;
  top: 0;
  width: 2rem;
  height: 2rem;
  background: var(--blue);
  color: var(--white);
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

.steps h3 {
  margin: 0.15rem 0 0.35rem;
  font-size: 1.15rem;
}

.steps p {
  color: var(--muted);
  margin: 0;
}

/* ——— Two column ——— */
.split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: start;
}

.info-block {
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
}

.info-block:first-child {
  border-top: none;
  padding-top: 0;
}

.info-block h3 {
  font-size: 1rem;
  margin-bottom: 0.35rem;
}

.info-block p,
.info-block a {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.info-block a:hover {
  color: var(--blue);
}

/* ——— Footer ——— */
.site-footer {
  background: var(--navy-deep);
  color: rgba(255, 255, 255, 0.65);
  padding: 3.5rem 0 1.75rem;
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-brand img {
  height: 48px;
  width: auto;
  margin-bottom: 1rem;
  padding: 0.5rem 0.75rem;
  background: var(--white);
  border-radius: 6px;
}

.footer-brand p {
  margin: 0;
  max-width: 28ch;
  line-height: 1.6;
}

.site-footer h4 {
  color: var(--white);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-footer li {
  margin-bottom: 0.55rem;
}

.site-footer a {
  color: rgba(255, 255, 255, 0.65);
}

.site-footer a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.45);
}

/* ——— Reveal on scroll ——— */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ——— Responsive ——— */
@media (max-width: 900px) {
  .feature-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .stats {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .split {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .journal-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--white);
    padding: 1rem 1.25rem 1.25rem;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
    gap: 0;
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--line);
  }

  .site-nav .btn {
    margin: 0.85rem 0 0;
    width: 100%;
  }

  .hero {
    min-height: auto;
  }

  .hero-inner {
    padding: 3.5rem 0 4rem;
  }

  .form-row-2 {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }

  .stats {
    gap: 1.75rem;
  }
}