/* ==========================================================================
   IEEE ISR/SIAS 2026 — shared stylesheet
   Edit this one file to restyle the whole site.
   ========================================================================== */

:root {
  --ieee-blue: #00629b;
  --deep-blue: #003f63;
  --sky-blue: #00a6d6;
  --light-bg: #f5f8fb;
  --white: #ffffff;
  --text: #1f2933;
  --muted: #5b6770;
  --border: #d9e2ec;
  --accent: #f4b400;
  --success: #1b8a5a;
  --warning-bg: #fff7e6;
  --warning-border: #f6c85f;
  --shadow: 0 12px 32px rgba(0, 45, 80, 0.12);
  --radius-lg: 22px;
  --radius-md: 14px;
  --max-width: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: var(--light-bg);
  line-height: 1.65;
}

a { color: var(--ieee-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* Skip link for keyboard / screen-reader users */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--deep-blue);
  color: var(--white);
  padding: 10px 16px;
  z-index: 300;
}
.skip-link:focus { left: 8px; top: 8px; }

/* ===== Header / navigation ===== */

.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  color: var(--deep-blue);
  letter-spacing: 0.02em;
}
.site-logo:hover { text-decoration: none; }

.logo-mark {
  width: 46px;
  height: 46px;
  flex: 0 0 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--ieee-blue), var(--sky-blue));
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 13px;
  line-height: 1.1;
  text-align: center;
}

.site-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px 16px;
  font-size: 14px;
  font-weight: 600;
}

.site-nav a {
  color: var(--muted);
  padding: 8px 2px;
  border-bottom: 2px solid transparent;
  transition: 0.2s ease;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--ieee-blue);
  border-color: var(--ieee-blue);
  text-decoration: none;
}

/* Mobile menu toggle (progressive enhancement: checkbox, no JS) */
.nav-toggle { display: none; }
.nav-toggle-label { display: none; }

/* ===== Hero ===== */

.hero {
  background:
    linear-gradient(120deg, rgba(0, 45, 80, 0.92), rgba(0, 98, 155, 0.78)),
    url("../img/Osaka.png") center center / cover no-repeat;
  color: var(--white);
}

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

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 84px 24px 76px;
}

.hero-inner.split {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 42px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.28);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 22px 0 18px;
  font-size: clamp(34px, 5vw, 60px);
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.hero .lead {
  max-width: 760px;
  margin: 0 0 28px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 18px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 30px;
}

.meta-pill {
  padding: 9px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 14px;
  font-weight: 700;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }

.hero-card {
  background: rgba(255, 255, 255, 0.13);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: var(--radius-lg);
  padding: 28px;
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow);
}

.hero-card h2 { margin: 0 0 12px; font-size: 24px; }
.hero-card p { margin: 0 0 18px; font-size: 15px; }

.status-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.92);
  color: #7a4b00;
  font-size: 13px;
  font-weight: 800;
  margin-bottom: 16px;
}

/* Compact hero for interior pages */
.hero.compact .hero-inner { padding: 56px 24px 52px; }
.hero.compact h1 { font-size: clamp(30px, 4vw, 46px); margin-bottom: 10px; }
.hero.compact .lead { margin-bottom: 0; }

/* ===== Buttons ===== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 800;
  transition: 0.2s ease;
  border: 2px solid transparent;
  cursor: pointer;
}
.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--accent);
  color: #1f2933;
  box-shadow: 0 10px 24px rgba(244, 180, 0, 0.3);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 28px rgba(244, 180, 0, 0.38);
}

.btn-outline {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.58);
  background: rgba(255, 255, 255, 0.08);
}
.btn-outline:hover { background: rgba(255, 255, 255, 0.18); }

.btn-blue { background: var(--ieee-blue); color: var(--white); }
.btn-blue:hover { background: var(--deep-blue); transform: translateY(-2px); }

.btn[aria-disabled="true"] {
  background: #e4eaf0;
  color: var(--muted);
  box-shadow: none;
  cursor: not-allowed;
  pointer-events: none;
}

/* ===== Layout ===== */

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 52px 24px 80px;
}

.section { margin-bottom: 56px; }
.section:last-child { margin-bottom: 0; }

.section-band {
  background: #eef4ff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 44px 0;
  margin: 0 0 56px;
}
.section-band > .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section-heading { margin-bottom: 24px; }

.section-heading span.kicker {
  display: inline-block;
  color: var(--ieee-blue);
  font-weight: 800;
  text-transform: uppercase;
  font-size: 13px;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(24px, 3vw, 36px);
  color: var(--deep-blue);
  letter-spacing: -0.02em;
}

.section-heading p {
  margin: 10px 0 0;
  color: var(--muted);
  max-width: 780px;
}

.prose { max-width: 820px; }
.prose p { margin: 0 0 18px; }
.prose h3 { color: var(--deep-blue); margin: 28px 0 10px; }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }

.two-column {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  gap: 26px;
  align-items: start;
}

/* ===== Cards ===== */

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: 0 8px 20px rgba(15, 40, 70, 0.06);
}

.card h3 { margin: 0 0 10px; color: var(--deep-blue); font-size: 20px; }
.card p { margin: 0 0 10px; color: var(--muted); font-size: 15px; }
.card p:last-child { margin-bottom: 0; }

.step-number {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--ieee-blue);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  margin-bottom: 16px;
}

.person-card { padding: 20px 22px; }
.person-card .role {
  color: var(--ieee-blue);
  font-weight: 800;
  font-size: 12px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.person-card .name { font-weight: 700; color: var(--deep-blue); font-size: 17px; }
.person-card .affil { color: var(--muted); font-size: 14px; }

/* ===== Important dates ===== */

.date-card { padding: 22px; border-top: 5px solid var(--ieee-blue); }
.date-card .label {
  color: var(--muted);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 8px;
}
.date-card .date {
  color: var(--deep-blue);
  font-weight: 900;
  font-size: 21px;
  line-height: 1.25;
}
.date-card.highlight {
  border-top-color: var(--accent);
  background: linear-gradient(180deg, #ffffff, #fffaf0);
}
.date-card.past { opacity: 0.62; }

.date-old { color: var(--muted); text-decoration: line-through; font-size: 15px; font-weight: 700; }
.date-new { color: var(--deep-blue); font-weight: 900; }

.date-table { width: 100%; border-collapse: collapse; background: var(--white); }
.date-table caption { text-align: left; color: var(--muted); padding-bottom: 10px; font-size: 14px; }
.date-table th, .date-table td {
  text-align: left;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
.date-table th { background: #eef4ff; color: var(--deep-blue); font-size: 13px; letter-spacing: 0.05em; text-transform: uppercase; }
.date-table tr:last-child td { border-bottom: none; }
.date-table td:first-child { font-weight: 700; color: var(--deep-blue); white-space: nowrap; }
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius-md); }

/* ===== Notices ===== */

.notice-box {
  background: var(--warning-bg);
  border: 1px solid var(--warning-border);
  border-radius: var(--radius-md);
  padding: 20px 22px;
  margin-bottom: 26px;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 14px;
  align-items: start;
}

.notice-icon {
  width: 34px;
  height: 34px;
  flex: 0 0 34px;
  border-radius: 50%;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  color: #3a2a00;
}

.notice-box strong { color: #614000; }
.notice-box p { margin: 8px 0 0; }
.notice-box p:first-child { margin-top: 0; }

.notice-box.success { background: #e8f7ee; border-color: #9bd8b4; }
.notice-box.success .notice-icon { background: var(--success); color: var(--white); }
.notice-box.success strong { color: #146c45; }

.notice-box.info { background: #eaf4fb; border-color: #a8cfe6; }
.notice-box.info .notice-icon { background: var(--ieee-blue); color: var(--white); }
.notice-box.info strong { color: var(--deep-blue); }

/* TBA block for pages awaiting content */
.tba {
  background: var(--white);
  border: 2px dashed #b7c9d9;
  border-radius: var(--radius-lg);
  padding: 40px 28px;
  text-align: center;
  color: var(--muted);
}
.tba h3 { margin: 0 0 10px; color: var(--deep-blue); font-size: 22px; }
.tba p { margin: 0 auto; max-width: 560px; }

/* ===== Announcements ===== */

.announcement-list { list-style: none; padding: 0; margin: 0; }

.announcement-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  line-height: 1.6;
}
.announcement-item:last-child { border-bottom: none; }

.announcement-date {
  font-size: 0.88rem;
  color: var(--muted);
  display: block;
  margin-bottom: 4px;
}

.badge {
  display: inline-block;
  color: var(--white);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 3px 9px;
  border-radius: 20px;
  margin-right: 8px;
  vertical-align: 1px;
  letter-spacing: 0.04em;
}
.badge-new { background: #dc2626; }
.badge-soon { background: var(--muted); }
.badge-pdf { background: var(--ieee-blue); }

/* ===== Lists ===== */

.info-list { list-style: none; padding: 0; margin: 16px 0 0; display: grid; gap: 10px; }
.info-list li { display: grid; grid-template-columns: 22px 1fr; gap: 10px; color: var(--muted); }
.check { color: var(--success); font-weight: 900; }

.topic-card ul { margin: 0; padding-left: 18px; color: var(--muted); }
.topic-card ul li { margin-bottom: 4px; }

/* ===== Image strip ===== */

.image-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.image-strip img {
  width: 100%;
  height: 210px;
  object-fit: cover;
  border-radius: var(--radius-md);
}
.image-strip img:first-child { object-position: top; }

/* ===== Flow ===== */

.publication-flow { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; }
.flow-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px;
  text-align: center;
  min-height: 128px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.flow-item strong { color: var(--deep-blue); display: block; margin-bottom: 6px; }
.flow-item span { color: var(--muted); font-size: 13px; }

/* ===== FAQ ===== */

.faq { display: grid; gap: 14px; }
details {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px 20px;
}
summary { cursor: pointer; font-weight: 800; color: var(--deep-blue); }
details p { color: var(--muted); margin: 12px 0 0; }

/* ===== Footer CTA + footer ===== */

.footer-cta {
  background: linear-gradient(135deg, var(--deep-blue), var(--ieee-blue));
  color: var(--white);
  border-radius: var(--radius-lg);
  padding: 36px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  box-shadow: var(--shadow);
}
.footer-cta h2 { margin: 0 0 8px; font-size: 26px; }
.footer-cta p { margin: 0; color: rgba(255, 255, 255, 0.86); }
.footer-cta a { color: var(--white); }

.site-footer {
  background: #0b2638;
  color: rgba(255, 255, 255, 0.78);
  padding: 40px 24px;
  font-size: 14px;
}
.footer-inner { max-width: var(--max-width); margin: 0 auto; text-align: center; }
.site-footer a { color: var(--white); font-weight: 700; }

.footer-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 34px;
  flex-wrap: wrap;
  margin: 22px 0;
}
.footer-logos img { height: 38px; width: auto; }
.footer-logos .logo-white { background: var(--white); padding: 6px 10px; border-radius: 6px; }

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin-bottom: 18px;
  padding: 0;
  list-style: none;
}

/* ===== Responsive ===== */

@media (max-width: 980px) {
  .header-inner { flex-direction: column; align-items: flex-start; gap: 10px; }
  .site-nav { gap: 4px 14px; font-size: 13.5px; }
  .hero-inner.split, .two-column { grid-template-columns: 1fr; }
  .grid-3, .grid-4, .publication-flow { grid-template-columns: repeat(2, 1fr); }
  .image-strip { grid-template-columns: 1fr; }
  .image-strip img { height: 200px; }
  .footer-cta { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 620px) {
  .hero-inner { padding: 56px 20px 50px; }
  main { padding: 40px 20px 64px; }
  .grid-2, .grid-3, .grid-4, .publication-flow { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .btn { width: 100%; }
  .notice-box { grid-template-columns: 1fr; }
  .card, .footer-cta { padding: 22px; }
}

@media print {
  .site-header, .hero-actions, .footer-cta { display: none; }
  body { background: #fff; }
}