/* CONFENIS 2027 - Clean European Academic Style */
/* IFIP WG 8.9 International Conference on Enterprise Information Systems */

:root {
  --primary: #2c3e50;
  --primary-dark: #1a252f;
  --accent: #3498db;
  --accent-dark: #2980b9;
  --gray-50: #f8f9fa;
  --gray-100: #ecf0f1;
  --gray-200: #d5dbdb;
  --gray-300: #bdc3c7;
  --gray-500: #7f8c8d;
  --gray-700: #34495e;
  --text: #2c3e50;
  --text-muted: #5d6d7e;
  --white: #ffffff;
  --border: #e1e8ed;
  --success: #27ae60;
  --warning: #f39c12;
  --max-width: 1180px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "Helvetica Neue", Helvetica, Arial, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--accent-dark); text-decoration: underline; }

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

/* ---------- Top utility bar ---------- */
.topbar {
  background: var(--primary-dark);
  color: var(--gray-200);
  font-size: 13px;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.topbar .wrap { display: flex; justify-content: space-between; align-items: center; }
.topbar a { color: var(--gray-200); }
.topbar a:hover { color: var(--white); }

/* ---------- Header / Nav ---------- */
.site-header {
  background: var(--primary);
  color: var(--white);
  border-bottom: 3px solid var(--accent);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 24px;
}
.brand { display: flex; align-items: center; gap: 16px; }
.brand-mark {
  width: 54px; height: 54px;
  background: var(--white);
  color: var(--primary);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 18px; letter-spacing: .5px;
  border: 2px solid var(--accent);
}
.brand-text h1 { font-size: 20px; font-weight: 600; letter-spacing: .3px; }
.brand-text p { font-size: 12px; color: var(--gray-200); margin-top: 2px; letter-spacing: 1px; text-transform: uppercase; }

.main-nav { background: var(--gray-50); border-bottom: 1px solid var(--border); }
.main-nav ul {
  list-style: none; display: flex; flex-wrap: wrap;
  max-width: var(--max-width); margin: 0 auto;
}
.main-nav li { }
.main-nav a {
  display: block; padding: 14px 20px;
  color: var(--primary); font-weight: 500; font-size: 14px;
  text-transform: uppercase; letter-spacing: .8px;
  border-bottom: 3px solid transparent;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--accent-dark);
  border-bottom-color: var(--accent);
  text-decoration: none;
  background: var(--white);
}

/* ---------- Layout ---------- */
.wrap { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
section { padding: 56px 0; }
section.tight { padding: 32px 0; }

h1, h2, h3, h4 { color: var(--primary); font-weight: 600; line-height: 1.25; }
h1 { font-size: 36px; margin-bottom: 18px; letter-spacing: -.3px; }
h2 { font-size: 26px; margin-bottom: 16px; padding-bottom: 10px; border-bottom: 2px solid var(--gray-100); }
h3 { font-size: 19px; margin: 18px 0 10px; }
h4 { font-size: 16px; margin: 14px 0 8px; }
p { margin-bottom: 14px; }
ul, ol { margin: 0 0 16px 20px; }
li { margin-bottom: 6px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: linear-gradient(rgba(26,37,47,0.78), rgba(44,62,80,0.85)),
              url('https://images.unsplash.com/photo-1516550893923-42d28e5677af?auto=format&fit=crop&w=1900&q=80') center/cover no-repeat;
  color: var(--white);
  padding: 110px 0 90px;
  text-align: left;
  border-bottom: 4px solid var(--accent);
}
.hero h1 { color: var(--white); font-size: 44px; max-width: 820px; }
.hero .lead { color: var(--gray-100); font-size: 19px; max-width: 720px; margin-top: 8px; }
.hero .meta {
  display: flex; flex-wrap: wrap; gap: 28px; margin-top: 28px;
  color: var(--white);
}
.hero .meta div { border-left: 3px solid var(--accent); padding-left: 14px; }
.hero .meta strong { display: block; font-size: 12px; letter-spacing: 1.2px; text-transform: uppercase; color: var(--gray-200); }
.hero .meta span { font-size: 17px; font-weight: 500; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--white) !important;
  padding: 12px 26px;
  font-size: 14px; font-weight: 600;
  letter-spacing: .8px; text-transform: uppercase;
  border: 2px solid var(--accent);
  transition: all .15s ease;
}
.btn:hover { background: var(--accent-dark); border-color: var(--accent-dark); text-decoration: none; }
.btn.ghost { background: transparent; color: var(--white) !important; }
.btn.ghost:hover { background: var(--white); color: var(--accent-dark) !important; border-color: var(--white); }
.btn-row { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }

/* ---------- Cards & grids ---------- */
.grid { display: grid; gap: 28px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  padding: 24px;
  transition: box-shadow .2s ease, transform .2s ease;
}
.card:hover { box-shadow: 0 8px 22px rgba(44,62,80,0.10); transform: translateY(-2px); }
.card h3 { color: var(--primary); margin-top: 0; }
.card p { color: var(--text-muted); font-size: 15px; }

.stat {
  text-align: center;
  background: var(--gray-50);
  padding: 28px 16px;
  border-left: 3px solid var(--accent);
}
.stat .num { font-size: 32px; font-weight: 700; color: var(--primary); display: block; }
.stat .lbl { font-size: 12px; letter-spacing: 1px; text-transform: uppercase; color: var(--gray-500); }

/* ---------- Section header ---------- */
.section-head { text-align: center; margin-bottom: 40px; }
.section-head .kicker { color: var(--accent); font-size: 12px; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; }
.section-head h2 { display: inline-block; border-bottom: none; padding-bottom: 0; margin-top: 6px; }
.section-head p { color: var(--text-muted); max-width: 720px; margin: 8px auto 0; }

/* ---------- Tables ---------- */
table {
  width: 100%; border-collapse: collapse;
  margin: 16px 0; font-size: 15px;
}
th, td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--gray-50); color: var(--primary); font-weight: 600; font-size: 13px; letter-spacing: .6px; text-transform: uppercase; }
tr:hover td { background: var(--gray-50); }

/* ---------- Important date list ---------- */
.dates-list { list-style: none; margin: 0; }
.dates-list li {
  display: flex; justify-content: space-between; padding: 14px 0;
  border-bottom: 1px solid var(--border);
}
.dates-list li:last-child { border-bottom: none; }
.dates-list .lbl { color: var(--text-muted); }
.dates-list .val { color: var(--primary); font-weight: 600; }
.dates-list .val.now { color: var(--accent-dark); }

/* ---------- Schedule ---------- */
.schedule-day { background: var(--gray-50); padding: 18px 22px; border-left: 4px solid var(--accent); margin: 26px 0 12px; }
.schedule-day h3 { margin: 0; color: var(--primary); }
.schedule-day p { margin: 4px 0 0; color: var(--text-muted); font-size: 14px; }

.slot {
  display: grid; grid-template-columns: 140px 1fr; gap: 18px;
  padding: 14px 0; border-bottom: 1px solid var(--border);
}
.slot:last-child { border-bottom: none; }
.slot time { color: var(--accent-dark); font-weight: 600; font-size: 14px; }
.slot .title { font-weight: 600; color: var(--primary); }
.slot .who { color: var(--text-muted); font-size: 14px; margin-top: 2px; }
.slot.keynote { background: rgba(52,152,219,0.06); padding-left: 14px; padding-right: 14px; }

/* ---------- Paper / Proceedings ---------- */
.paper-list { list-style: none; margin: 0; }
.paper-list li {
  padding: 22px;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  margin-bottom: 14px;
  background: var(--white);
  transition: background .15s ease;
}
.paper-list li:hover { background: var(--gray-50); }
.paper-list .pno { color: var(--accent); font-weight: 700; font-size: 12px; letter-spacing: 1.2px; text-transform: uppercase; }
.paper-list h3 { margin: 6px 0; font-size: 18px; }
.paper-list h3 a { color: var(--primary); }
.paper-list h3 a:hover { color: var(--accent-dark); text-decoration: none; }
.paper-list .authors { color: var(--text-muted); font-size: 14px; font-style: italic; }
.paper-list .affil { color: var(--gray-500); font-size: 13px; }

/* Paper detail */
.paper-header {
  background: var(--primary);
  color: var(--white);
  padding: 50px 0 38px;
  border-bottom: 4px solid var(--accent);
}
.paper-header .kicker { color: var(--accent); font-size: 12px; letter-spacing: 2px; text-transform: uppercase; }
.paper-header h1 { color: var(--white); font-size: 30px; margin: 10px 0 14px; max-width: 920px; }
.paper-header .authors { color: var(--gray-100); font-size: 16px; }
.paper-header .affil { color: var(--gray-200); font-size: 14px; margin-top: 4px; }

.paper-body { max-width: 820px; margin: 0 auto; padding: 50px 24px; }
.paper-body h2 { font-size: 22px; margin-top: 30px; }
.paper-body .abstract {
  background: var(--gray-50);
  border-left: 4px solid var(--accent);
  padding: 20px 24px;
  margin: 24px 0;
}
.paper-body .abstract strong { color: var(--primary); display: block; margin-bottom: 6px; letter-spacing: 1px; font-size: 12px; text-transform: uppercase; }
.paper-body .keywords {
  font-size: 14px; color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 14px; margin-top: 24px;
}
.paper-body .keywords strong { color: var(--primary); }
.paper-meta {
  display: grid; grid-template-columns: repeat(2,1fr); gap: 14px;
  background: var(--gray-50); padding: 18px 22px;
  font-size: 14px; margin: 24px 0;
}
.paper-meta div strong { display: block; color: var(--primary); font-size: 12px; text-transform: uppercase; letter-spacing: 1px; }

/* References */
.references { list-style: none; counter-reset: ref; margin: 0; font-size: 14px; }
.references li { counter-increment: ref; padding: 10px 0 10px 32px; position: relative; border-bottom: 1px dotted var(--border); }
.references li::before {
  content: counter(ref) ".";
  position: absolute; left: 0; top: 10px;
  color: var(--accent); font-weight: 600;
}

/* ---------- Committee ---------- */
.person-list { display: grid; grid-template-columns: repeat(2,1fr); gap: 12px 28px; }
.person-list .person {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}
.person-list .name { font-weight: 600; color: var(--primary); }
.person-list .affil { color: var(--text-muted); font-size: 14px; }

.chair-card {
  display: grid; grid-template-columns: 110px 1fr; gap: 22px;
  background: var(--gray-50); padding: 22px;
  border-left: 4px solid var(--accent);
  margin-bottom: 18px;
}
.chair-card .avatar {
  width: 110px; height: 110px;
  background: var(--primary);
  color: var(--white);
  display: flex; align-items: center; justify-content: center;
  font-size: 36px; font-weight: 700;
}
.chair-card .role { color: var(--accent); font-size: 12px; letter-spacing: 1.4px; text-transform: uppercase; font-weight: 600; }
.chair-card .name { font-size: 19px; color: var(--primary); font-weight: 600; margin: 4px 0; }
.chair-card .affil { color: var(--text-muted); font-size: 14px; }

/* ---------- Venue ---------- */
.figure { margin: 22px 0; }
.figure img { border: 1px solid var(--border); }
.figure figcaption { font-size: 13px; color: var(--text-muted); margin-top: 8px; font-style: italic; text-align: center; }

.venue-info {
  background: var(--gray-50);
  padding: 24px;
  border-left: 4px solid var(--accent);
  margin: 22px 0;
}
.venue-info p { margin: 6px 0; }
.venue-info .label { color: var(--accent-dark); font-weight: 600; }

/* Banner block */
.banner {
  background: linear-gradient(rgba(44,62,80,0.82), rgba(44,62,80,0.92)),
              url('https://images.unsplash.com/photo-1538970272646-f61fabb3a8a2?auto=format&fit=crop&w=1700&q=80') center/cover no-repeat;
  color: var(--white);
  padding: 70px 0;
  text-align: center;
}
.banner h2 { color: var(--white); border: none; }
.banner p { color: var(--gray-100); max-width: 720px; margin: 10px auto 22px; }

/* Springer / IFIP badge strip */
.partner-strip {
  background: var(--gray-50);
  padding: 28px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.partner-strip .wrap {
  display: flex; align-items: center; justify-content: space-around;
  flex-wrap: wrap; gap: 22px;
}
.partner-strip .badge {
  text-align: center; color: var(--text-muted); font-size: 13px;
  text-transform: uppercase; letter-spacing: 1.5px;
}
.partner-strip .badge strong { display: block; color: var(--primary); font-size: 15px; letter-spacing: .3px; text-transform: none; margin-bottom: 2px; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--primary-dark);
  color: var(--gray-200);
  padding: 50px 0 18px;
  margin-top: 60px;
}
.site-footer .grid-4 { gap: 32px; }
.site-footer h4 { color: var(--white); font-size: 14px; text-transform: uppercase; letter-spacing: 1.2px; margin-bottom: 14px; padding-bottom: 8px; border-bottom: 1px solid rgba(255,255,255,0.12); }
.site-footer a { color: var(--gray-200); }
.site-footer a:hover { color: var(--white); }
.site-footer ul { list-style: none; margin: 0; }
.site-footer li { margin-bottom: 6px; font-size: 14px; }
.site-footer p { font-size: 14px; color: var(--gray-300); }
.copyright { border-top: 1px solid rgba(255,255,255,0.12); padding-top: 16px; margin-top: 32px; text-align: center; font-size: 13px; color: var(--gray-300); }

/* ---------- Utilities ---------- */
.muted { color: var(--text-muted); }
.small { font-size: 13px; }
.center { text-align: center; }
.spacer { height: 28px; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2,1fr); }
  .person-list { grid-template-columns: 1fr; }
  .hero { padding: 70px 0 60px; }
  .hero h1 { font-size: 32px; }
  .main-nav ul { flex-direction: column; }
  .main-nav li { width: 100%; }
}
@media (max-width: 600px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .paper-meta { grid-template-columns: 1fr; }
  .chair-card { grid-template-columns: 1fr; }
  .slot { grid-template-columns: 1fr; }
  h1 { font-size: 28px; }
  .hero h1 { font-size: 26px; }
}