/* --- CSS Variables & Design Tokens --- */
:root {
  --bg-main: #0C293F;
  --bg-card: #001C34;
  --bg-light: #F7F7F7;
  --accent-gradient: linear-gradient(135deg, #0C293F 0%, #9FA463 100%);
  --text-main: #FFFFFF;
  --text-muted: #F7F7F7;
  --text-dark: #080504;
  --accent: #9FA463;
  --dark-transparent: rgba(6, 28, 50, 0.65);
  --radius: 6px;
  --transition: all 0.3s ease;
  --font-heading: 'Unna', Georgia, Cambria, 'Times New Roman', Times, serif;
  --font-body: 'Mada', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

/* Helper class to hide content visually while keeping it for screen readers */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  background-image: linear-gradient(var(--dark-transparent), var(--dark-transparent)), url(https://vetsec.org/wp-content/uploads/2024/01/VetSec_texture_icon.jpg);
  background-repeat: no-repeat;
  background-position: 50% 50%;
  background-size: cover;
  background-attachment: fixed;

}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 5rem 0;
}

h1, h2, h3, h4 { 
  font-family: var(--font-heading);
  text-align: center;
  margin-bottom: 2.5rem;
}
h2 {
  font-size: 2.5rem; 
  text-decoration: underline;
  text-decoration-style: dashed;
  text-decoration-color: var(--accent);
  text-underline-offset: 12px;
}

a:focus-visible,
button:focus-visible,
label:focus-visible {
  outline: 3px solid #8BD8BD;
  outline-offset: 3px;
}

.right { float:right; }

/* --- Navigation --- */
nav {
  position: sticky;
  top: 0;
  background: var(--dark-transparent);
  backdrop-filter: blur(8px);
  z-index: 100;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-main);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--accent);
}

/* --- Buttons --- */
.btn-wrapper {
  width:100%;
  text-align:center;
  margin:1rem auto;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1.2rem;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: var(--text-main);
  box-shadow: 0 4px 20px rgba(153, 153, 153, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(153, 153, 153, 0.6);
}

/* --- Hero Section & CSS Animation --- */
.hero {
  text-align: center;
  padding: 7rem 0 4rem;
  position: relative;
}

.badge {
  display: inline-block;
  padding: 0.25rem 1rem;
  background: var(--accent);
  color: var(--text-dark);
  border-radius: 9999px;
  margin-bottom: 1.5rem;
  border: 1px solid var(--accent);
}
@media (prefers-reduced-motion: no-preference) {
  .badge { animation: pulse 2s infinite; }
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.85; transform: scale(1.1); }
}

.hero h1 {
  font-size: 3.5rem;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 650px;
  margin: 0 auto 2.5rem;
}

/* --- Countdown Timer --- */
.timer {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 3rem;
}

.timer-block {
  background: var(--bg-light);
  padding: 1.25rem 1rem;
  border-radius: var(--radius);
  min-width: 90px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.timer-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  display: block;
}

.timer-label {
  font-size: 0.75rem;
  color: var(--text-dark);
  text-transform: uppercase;
  letter-spacing: 1px;
}

section.container {
  padding: 2rem;
  margin: 4rem auto;
  background: rgba(247, 247, 247, 0.85);
  color: var(--text-dark);
  border-radius: var(--radius);
}

/* --- Highlights Cards --- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-light);
  padding: 2rem;
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
}

.card h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  text-align:left;
}

/* --- Schedule Tabs (CSS Only) --- */
.schedule-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2rem;
}

.tab-btn {
  padding: 0.5rem 1.5rem;
  background: var(--bg-card);
  color: var(--text-muted);
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 600;
  border: 1px solid var(--accent);
  transition: var(--transition);
}

/* Target schedule tabs using CSS :has() selector or radio inputs */
input[type="radio"] {
  display: none;
}

#day1:checked ~ .schedule-tabs label[for="day1"],
#day2:checked ~ .schedule-tabs label[for="day2"],
#day3:checked ~ .schedule-tabs label[for="day3"] {
  background: var(--accent-gradient);
  color: #fff;
}

.schedule-content {
  display: none;
}

#day1:checked ~ #content-day1,
#day2:checked ~ #content-day2,
#day3:checked ~ #content-day3 {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.talk-card, .break-card {
  background: var(--text-muted);
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.5rem;  
  border-radius: var(--radius);
  align-items: center;
}
.talk-card {
  padding: 1.5rem;
  border-left: 4px solid var(--accent);
}
.break-card {
  padding: 0.85rem 1.5rem;
  border-left: 4px dashed var(--accent); /* Dashed left border signals a pause */
}

.talk-time {
  font-weight: 600;
  color: var(--text-dark);
  font-size: 1.2rem;
}
.break-card .talk-time { font-size: 1rem; }

.speaker-name {
  color: var(--accent);
  font-size: 0.875rem;
  margin-top: 0.25rem;
  font-weight: 600;
}

.schedule-content h3 { text-align:left; margin-bottom:0.75rem; }
.talk-summary { margin-top:1rem; }
.break-card.major-break { border-left-color: var(--accent); }
.keynote {
  border-left-color: var(--text-main);
  background-color: #9fa463bd;
  color: var(--text-main);
}
.keynote .content { font-size: 1.2rem; }
.keynote .speaker-name { color:var(--text-dark); font-size: inherit; }

/* --- Footer --- */
footer {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  background: var(--dark-transparent);
  backdrop-filter: blur(8px);
  padding: 2rem 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}
footer a { color: var(--accent); }

/* --- Responsive Styling --- */
@media (max-width: 768px) {
  .hero h1 { font-size: 2.25rem; }
  .talk-card { grid-template-columns: 1fr; gap: 0.5rem; }
  .nav-links { display: none; }
  .break-card { grid-template-columns: 1fr; gap: 0.25rem; }
}