/* ECE Student Conference 2026 — minimal site stylesheet */

:root{
  --deep-blue:#0759B6;
  --blue:#0965BB;
  --light-blue:#0876C3;
  --teal:#079B9E;
  --green:#20B174;
  --sec-green:#18A96B;
  --accent:#FFB52B;
  --navy:#0C1B2A;

  --ink:#0C1B2A;
  --ink-soft:#3C4A5A;
  --bg:#FFFFFF;
  --bg-alt:#F4F7FA;
  --border:#E2E8EF;
  --radius:10px;
  --max-w:1120px;
  --font: "Inter", "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
  --font-display: "Manrope", "Inter", "Segoe UI", system-ui, -apple-system, Arial, sans-serif;
}

*{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
img,svg{ max-width:100%; display:block; }
a{ color:var(--blue); text-decoration:none; }
a:hover{ text-decoration:underline; }
h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:800;
  letter-spacing:-0.01em;
  line-height:1.2;
  color:var(--navy);
  margin:0 0 .6em;
}
h1{ font-size:clamp(1.9rem,4vw,2.7rem); }
h2{ font-size:clamp(1.4rem,2.6vw,1.9rem); margin-top:0; font-weight:700; }
h3{ font-size:1.15rem; font-weight:700; }
p{ margin:0 0 1em; color:var(--ink-soft); }
ul{ margin:0 0 1em; padding-left:1.25em; color:var(--ink-soft); }
li{ margin-bottom:.35em; }

.container{
  max-width:var(--max-w);
  margin:0 auto;
  padding:0 20px;
}

/* Skip link */
.skip-link{
  position:absolute; left:-999px; top:auto;
  background:var(--navy); color:#fff; padding:10px 16px; border-radius:0 0 8px 0; z-index:200;
}
.skip-link:focus{ left:0; top:0; }

/* Header */
.site-header{
  position:sticky; top:0; z-index:100;
  background:rgba(255,255,255,.96);
  border-bottom:1px solid var(--border);
  backdrop-filter:saturate(180%) blur(6px);
}
.header-inner{
  display:flex; align-items:center; gap:16px;
  padding:12px 20px;
  max-width:1360px; margin:0 auto;
}
.brand{ display:flex; align-items:center; gap:10px; flex-shrink:0; }
.brand img,.brand svg{ height:44px; width:auto; }
.brand-text{ font-family:var(--font-display); font-weight:700; font-size:.95rem; color:var(--navy); white-space:nowrap; }

.main-nav{ display:flex; align-items:center; margin-left:auto; flex-wrap:nowrap; }
.main-nav a{
  font-family:var(--font-display);
  color:var(--ink); font-weight:600; font-size:.85rem;
  padding:8px 10px; white-space:nowrap;
  border-right:1px solid var(--border);
}
.main-nav a:last-child{ border-right:none; }
.main-nav a:hover{ background:var(--bg-alt); text-decoration:none; color:var(--deep-blue); }
.main-nav a[aria-current="page"]{ color:var(--deep-blue); background:var(--bg-alt); }

.header-actions{ display:flex; align-items:center; gap:10px; margin-left:12px; flex-shrink:0; }

.lang-switch{ font-family:var(--font-display); display:flex; gap:6px; font-size:.85rem; font-weight:700; }
.lang-switch a{ padding:4px 7px; border-radius:6px; color:var(--ink-soft); }
.lang-switch a[aria-current="true"]{ color:var(--deep-blue); background:var(--bg-alt); }

.btn{
  display:inline-block; font-family:var(--font-display); font-weight:700; font-size:.93rem;
  padding:10px 18px; border-radius:8px; border:2px solid transparent;
  cursor:pointer; white-space:nowrap;
}
.btn:hover{ text-decoration:none; }
.btn-primary{ background:var(--deep-blue); color:#fff; }
.btn-primary:hover{ background:var(--navy); color:#fff; }
.btn-accent{ background:var(--accent); color:var(--navy); }
.btn-accent:hover{ background:#ffc65a; color:var(--navy); }
.btn-outline{ border-color:var(--deep-blue); color:var(--deep-blue); background:#fff; }
.btn-outline:hover{ background:var(--deep-blue); color:#fff; }
.btn-sm{ padding:7px 14px; font-size:.85rem; }
.btn-disabled{ background:var(--bg-alt); color:var(--ink-soft); border:2px dashed var(--border); cursor:not-allowed; }
.btn-disabled:hover{ background:var(--bg-alt); color:var(--ink-soft); text-decoration:none; }

.nav-toggle{
  display:none; margin-left:auto;
  background:none; border:1px solid var(--border); border-radius:8px;
  width:42px; height:42px; align-items:center; justify-content:center;
  font-size:1.3rem; cursor:pointer; color:var(--navy);
}

/* Hero */
.hero{
  background:linear-gradient(135deg, var(--navy) 0%, var(--deep-blue) 55%, var(--teal) 100%);
  color:#fff; padding:56px 0 44px;
}
.hero .container{ text-align:center; }
.hero-logo{
  height:150px; width:auto; margin:0 auto 24px;
  filter:brightness(0) invert(1);
}
.hero-eyebrow{ font-family:var(--font-display); font-weight:700; letter-spacing:.06em; text-transform:uppercase; font-size:.8rem; color:var(--accent); margin-bottom:10px; }
.hero h1{ color:#fff; margin-bottom:8px; }
.hero-sub{ color:#dbe8f7; font-size:1.05rem; margin-bottom:4px; }
.hero-meta{
  display:flex; flex-wrap:wrap; justify-content:center; gap:10px 22px;
  margin:18px 0 26px; font-weight:600; color:#fff;
}
.hero-meta span{ display:flex; align-items:center; gap:8px; font-size:1rem; }
.hero-actions{ display:flex; flex-wrap:wrap; justify-content:center; gap:14px; }
.hero .btn-outline{ border-color:#fff; color:#fff; background:transparent; }
.hero .btn-outline:hover{ background:#fff; color:var(--navy); }

/* Dates strip */
.dates-strip{ background:var(--bg-alt); border-bottom:1px solid var(--border); padding:34px 0; }
.dates-strip h2{ text-align:center; margin-bottom:22px; }
.dates-grid{
  display:grid; grid-template-columns:repeat(4,1fr); gap:16px;
}
.date-card{
  background:#fff; border:1px solid var(--border); border-radius:var(--radius);
  padding:18px 16px; text-align:center; border-top:4px solid var(--deep-blue);
}
.date-card:nth-child(2){ border-top-color:var(--teal); }
.date-card:nth-child(3){ border-top-color:var(--green); }
.date-card:nth-child(4){ border-top-color:var(--accent); }
.date-card .date{ font-family:var(--font-display); font-weight:800; font-size:1.15rem; color:var(--navy); margin-bottom:4px; }
.date-card .label{ font-size:.88rem; color:var(--ink-soft); }

/* Sections */
.section{ padding:48px 0; }
.section-alt{ background:var(--bg-alt); }
.section-head{ max-width:680px; margin:0 auto 30px; text-align:center; }

.cards{ display:grid; grid-template-columns:repeat(3,1fr); gap:20px; }
.card{
  background:#fff; border:1px solid var(--border); border-radius:var(--radius);
  padding:24px; display:flex; flex-direction:column; gap:8px;
}
.card h3{ margin-bottom:2px; }
.card .more{ margin-top:auto; font-weight:700; }

.topics-grid{ display:grid; grid-template-columns:repeat(2,1fr); gap:16px; }
.topic-card{
  background:#fff; border:1px solid var(--border); border-left:5px solid var(--deep-blue);
  border-radius:var(--radius); padding:18px 20px;
}
.topic-card:nth-child(2){ border-left-color:var(--teal); }
.topic-card:nth-child(3){ border-left-color:var(--green); }
.topic-card:nth-child(4){ border-left-color:var(--accent); }
.topic-card h3{ margin-bottom:8px; }
.topic-card ul{ margin-bottom:0; padding-left:1.1em; font-size:.93rem; }

.center{ text-align:center; }
.mt{ margin-top:28px; }

/* Steps (For Authors) */
.steps{ display:flex; flex-direction:column; gap:0; }
.step{
  display:grid; grid-template-columns:64px 1fr; gap:20px;
  padding:26px 0; border-bottom:1px solid var(--border);
}
.step:last-child{ border-bottom:none; }
.step-num{
  width:48px; height:48px; border-radius:50%;
  background:var(--deep-blue); color:#fff; font-family:var(--font-display); font-weight:800; font-size:1.2rem;
  display:flex; align-items:center; justify-content:center;
}
.step-deadline{
  display:inline-block; background:var(--bg-alt); color:var(--deep-blue);
  font-weight:700; font-size:.85rem; padding:4px 10px; border-radius:6px; margin-bottom:8px;
}

/* CMT callout */
.cmt-box{
  background:var(--navy); color:#fff; border-radius:var(--radius);
  padding:32px; text-align:center; margin-top:10px;
}
.cmt-box h2{ color:#fff; }
.cmt-box p{ color:#cfe0f2; }
.cmt-note{
  background:#fff3d9; border:1px solid #f0d089; color:#7a5b12;
  border-radius:8px; padding:10px 14px; font-size:.9rem; margin-top:16px; display:inline-block;
}
.no-alt-submission{
  border:1px dashed var(--border); border-radius:8px; padding:14px 16px;
  background:var(--bg-alt); font-size:.92rem; margin-top:18px;
}

/* Tables */
table{ width:100%; border-collapse:collapse; margin-bottom:1.2em; background:#fff; }
th,td{ text-align:left; padding:10px 12px; border-bottom:1px solid var(--border); font-size:.94rem; }
th{ color:var(--navy); font-size:.85rem; text-transform:uppercase; letter-spacing:.03em; background:var(--bg-alt); }
td{ color:var(--ink-soft); }

/* Downloads */
.downloads{ display:grid; grid-template-columns:repeat(2,1fr); gap:14px; }
.download-card{
  display:flex; align-items:center; justify-content:space-between; gap:12px;
  border:1px solid var(--border); border-radius:var(--radius); padding:16px 18px; background:#fff;
}
.download-card .fname{ font-weight:700; color:var(--navy); font-size:.95rem; }
.download-card .fmeta{ font-size:.82rem; color:var(--ink-soft); }

/* Committees */
.committee-block{ margin-bottom:34px; }
.committee-block:last-child{ margin-bottom:0; }

/* Program */
.program-placeholder{
  border:1px dashed var(--border); border-radius:var(--radius);
  padding:40px 24px; text-align:center; background:var(--bg-alt);
}
.session{ display:flex; gap:16px; padding:12px 0; border-bottom:1px solid var(--border); }
.session .time{ width:80px; flex-shrink:0; font-weight:700; color:var(--deep-blue); }

/* Venue */
.venue-grid{ display:grid; grid-template-columns:1.1fr 1fr; gap:28px; align-items:start; }
.map-embed{ border-radius:var(--radius); overflow:hidden; border:1px solid var(--border); }
.map-embed iframe{ width:100%; height:320px; border:0; display:block; }
.contact-box{
  border:1px solid var(--border); border-radius:var(--radius); padding:20px; background:var(--bg-alt);
}

/* Footer */
.site-footer{ background:var(--navy); color:#cfd9e6; padding:36px 0 22px; margin-top:20px; }
.footer-inner{ display:flex; flex-wrap:wrap; justify-content:space-between; gap:24px; }
.footer-brand{ display:flex; align-items:center; gap:10px; }
.footer-brand img,.footer-brand svg{ height:28px; width:auto; }
.footer-links{ display:flex; flex-wrap:wrap; gap:16px; }
.footer-links a{ color:#cfd9e6; font-size:.9rem; }
.footer-links a:hover{ color:#fff; }
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.12); margin-top:22px; padding-top:16px;
  font-size:.82rem; color:#8fa1b6; display:flex; flex-wrap:wrap; gap:10px 20px; justify-content:space-between;
}

.cmt-ack{
  margin-top:24px; padding-top:18px; border-top:1px solid var(--border);
  font-size:.82rem; color:var(--ink-soft);
}

.note-callout{
  background:#eef6ff; border:1px solid #c7e0f7; border-radius:8px;
  padding:14px 16px; font-size:.92rem; margin:18px 0;
}

/* Nav collapses to a hamburger menu well before the 7 items would ever
   overflow or wrap (needs ~1370px+ to sit comfortably on one line) */
@media (max-width: 1450px){
  .main-nav{
    display:none; position:absolute; top:100%; left:0; right:0;
    background:#fff; border-bottom:1px solid var(--border);
    flex-direction:column; padding:10px; gap:2px;
    box-shadow:0 8px 18px rgba(12,27,42,.08);
  }
  .main-nav.open{ display:flex; }
  .main-nav a{ padding:12px 14px; font-size:.93rem; border-right:none; border-bottom:1px solid var(--border); border-radius:8px; white-space:normal; }
  .main-nav a:last-child{ border-bottom:none; }
  .nav-toggle{ display:flex; }
  .header-actions{ margin-left:auto; }
}

/* Mobile */
@media (max-width: 880px){
  .cards,.topics-grid,.dates-grid,.downloads,.venue-grid{ grid-template-columns:1fr; }
  .step{ grid-template-columns:44px 1fr; }
  .footer-inner{ flex-direction:column; }
}

@media (max-width: 480px){
  .hero{ padding:40px 0 32px; }
  .hero-logo{ height:100px; margin-bottom:16px; }
  .header-inner{ padding:10px 14px; gap:8px; }
  .brand-text{ display:none; }
  .brand img,.brand svg{ height:30px; }
  .nav-toggle{ width:36px; height:36px; font-size:1.1rem; }
  .header-actions{ gap:6px; margin-left:auto; }
  .lang-switch{ gap:2px; font-size:.78rem; }
  .lang-switch a{ padding:3px 5px; }
  .header-actions .btn{ padding:6px 9px; font-size:.68rem; }
}

@media (max-width: 400px){
  .header-inner{ gap:5px; padding:10px 10px; }
  .brand img,.brand svg{ height:26px; }
  .nav-toggle{ width:32px; height:32px; font-size:1rem; }
  .lang-switch{ gap:1px; font-size:.72rem; }
  .lang-switch a{ padding:2px 4px; }
  .header-actions{ gap:4px; }
  .header-actions .btn{ padding:5px 7px; font-size:.6rem; }
}