/* ===== World Bitcoin Forum - Modern Revamp ===== */
:root {
  --primary: #1a56db;
  --primary-dark: #1e3a8a;
  --accent: #f59e0b;
  --accent-hover: #d97706;
  --dark: #0f172a;
  --dark-2: #1e293b;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --white: #ffffff;
  --font: 'Inter', system-ui, -apple-system, sans-serif;
  --font-heading: 'Inter', system-ui, -apple-system, sans-serif;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -2px rgba(0,0,0,.05);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,.1), 0 10px 10px -5px rgba(0,0,0,.04);
  --transition: all .3s ease;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: var(--font); color: var(--dark); line-height: 1.7; background: var(--white); }
img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }
h1,h2,h3,h4,h5,h6 { font-family: var(--font-heading); font-weight: 700; line-height: 1.2; color: var(--dark); }
h1 { font-size: 2.75rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
p { margin-bottom: 1rem; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== HEADER / NAV ===== */
.site-header { background: var(--white); border-bottom: 1px solid var(--gray-200); position: sticky; top: 0; z-index: 1000; backdrop-filter: blur(12px); background: rgba(255,255,255,.95); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 16px 24px; max-width: 1200px; margin: 0 auto; }
.logo { font-size: 1.5rem; font-weight: 800; color: var(--dark); }
.logo span { color: var(--primary); }
.logo a { color: inherit; }
.logo a:hover { color: var(--primary); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--dark); margin: 6px 0; transition: var(--transition); }
.main-nav ul { display: flex; gap: 8px; align-items: center; }
.main-nav a { padding: 8px 16px; border-radius: 8px; color: var(--gray-600); font-weight: 500; font-size: .95rem; }
.main-nav a:hover, .main-nav a.active { color: var(--primary); background: rgba(26,86,219,.06); }
.nav-cta { background: var(--primary) !important; color: var(--white) !important; padding: 10px 20px !important; border-radius: 8px !important; font-weight: 600 !important; }
.nav-cta:hover { background: var(--primary-dark) !important; }
.social-links { display: flex; gap: 12px; align-items: center; }
.social-links a { color: var(--gray-400); font-size: 1.2rem; }
.social-links a:hover { color: var(--primary); }

/* ===== HERO ===== */
.hero { background: linear-gradient(135deg, var(--dark) 0%, var(--primary-dark) 50%, var(--primary) 100%); color: var(--white); padding: 100px 0 80px; position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E"); }
.hero .container { position: relative; z-index: 1; text-align: center; }
.hero h1 { font-size: 3.5rem; margin-bottom: 20px; font-weight: 800; }
.hero .subtitle { font-size: 1.3rem; opacity: .9; margin-bottom: 12px; font-weight: 400; }
.hero .event-meta { display: inline-flex; gap: 24px; flex-wrap: wrap; justify-content: center; margin: 24px 0 36px; }
.hero .event-meta span { display: flex; align-items: center; gap: 8px; font-size: 1.05rem; opacity: .85; }
.hero-cta { display: inline-block; background: var(--accent); color: var(--dark); padding: 16px 40px; border-radius: 50px; font-size: 1.15rem; font-weight: 700; transition: var(--transition); }
.hero-cta:hover { background: var(--accent-hover); color: var(--dark); transform: translateY(-2px); box-shadow: 0 8px 25px rgba(245,158,11,.35); }

/* ===== SECTIONS ===== */
.section { padding: 80px 0; }
.section-alt { background: var(--gray-100); }
.section-dark { background: var(--dark); color: var(--white); }
.section-dark h2, .section-dark h3, .section-dark h4 { color: var(--white); }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 { margin-bottom: 12px; }
.section-header p { color: var(--gray-500); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }
.section-label { display: inline-block; background: rgba(26,86,219,.1); color: var(--primary); padding: 6px 16px; border-radius: 50px; font-size: .85rem; font-weight: 600; text-transform: uppercase; letter-spacing: .5px; margin-bottom: 12px; }

/* ===== GRID UTILITIES ===== */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.flex-center { display: flex; align-items: center; justify-content: center; }

/* ===== CARDS ===== */
.card { background: var(--white); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); transition: var(--transition); border: 1px solid var(--gray-200); }
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.card-icon { width: 56px; height: 56px; border-radius: 12px; background: rgba(26,86,219,.1); display: flex; align-items: center; justify-content: center; margin-bottom: 20px; font-size: 1.5rem; color: var(--primary); }
.card h3 { margin-bottom: 12px; }
.card p { color: var(--gray-500); font-size: .95rem; }

/* ===== SPEAKER CARDS ===== */
.speaker-card { text-align: center; background: var(--white); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); transition: var(--transition); border: 1px solid var(--gray-200); }
.speaker-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.speaker-card .speaker-img { width: 100%; aspect-ratio: 1; object-fit: cover; background: var(--gray-200); }
.speaker-card .speaker-info { padding: 20px; }
.speaker-card h3 { font-size: 1.1rem; margin-bottom: 4px; }
.speaker-card .speaker-role { color: var(--gray-500); font-size: .85rem; margin-bottom: 8px; }
.speaker-card .speaker-tag { display: inline-block; background: rgba(26,86,219,.1); color: var(--primary); padding: 4px 12px; border-radius: 50px; font-size: .75rem; font-weight: 600; }

/* ===== SPEAKER BIO (full page) ===== */
.speaker-hero { background: linear-gradient(135deg, var(--dark) 0%, var(--primary-dark) 100%); color: var(--white); padding: 60px 0; }
.speaker-profile { display: flex; gap: 40px; align-items: flex-start; }
.speaker-profile .speaker-photo { width: 200px; height: 200px; border-radius: 50%; object-fit: cover; border: 4px solid rgba(255,255,255,.2); flex-shrink: 0; background: var(--gray-300); }
.speaker-profile h1 { font-size: 2.5rem; margin-bottom: 8px; }
.speaker-profile .speaker-title { font-size: 1.1rem; opacity: .8; margin-bottom: 16px; }
.speaker-bio { max-width: 800px; margin: 0 auto; }
.speaker-bio p { font-size: 1.05rem; line-height: 1.8; color: var(--gray-600); }

/* ===== TICKET CARDS ===== */
.ticket-card { background: var(--white); border-radius: var(--radius); padding: 32px; border: 2px solid var(--gray-200); text-align: center; transition: var(--transition); }
.ticket-card:hover { border-color: var(--primary); box-shadow: var(--shadow-lg); }
.ticket-card.featured { border-color: var(--accent); position: relative; }
.ticket-card.featured::before { content: 'Popular'; position: absolute; top: -12px; left: 50%; transform: translateX(-50%); background: var(--accent); color: var(--dark); padding: 4px 16px; border-radius: 50px; font-size: .8rem; font-weight: 700; }
.ticket-card h3 { margin-bottom: 8px; }
.ticket-card .price { font-size: 2.5rem; font-weight: 800; color: var(--primary); margin: 16px 0; }
.ticket-card .price small { font-size: .9rem; color: var(--gray-400); font-weight: 400; }
.ticket-card ul { margin: 24px 0; text-align: left; }
.ticket-card li { padding: 8px 0; color: var(--gray-600); font-size: .95rem; border-bottom: 1px solid var(--gray-100); display: flex; align-items: center; gap: 8px; }
.ticket-card li::before { content: '\2713'; color: var(--primary); font-weight: 700; }

/* ===== BUTTONS ===== */
.btn { display: inline-block; padding: 12px 28px; border-radius: 8px; font-weight: 600; font-size: 1rem; cursor: pointer; transition: var(--transition); border: none; text-align: center; }
.btn-primary { background: var(--primary); color: var(--white); }
.btn-primary:hover { background: var(--primary-dark); color: var(--white); transform: translateY(-1px); }
.btn-accent { background: var(--accent); color: var(--dark); }
.btn-accent:hover { background: var(--accent-hover); color: var(--dark); }
.btn-outline { border: 2px solid var(--primary); color: var(--primary); background: transparent; }
.btn-outline:hover { background: var(--primary); color: var(--white); }
.btn-block { display: block; width: 100%; }
.btn-lg { padding: 16px 36px; font-size: 1.1rem; }

/* ===== NEWS / BLOG ===== */
.post-card { background: var(--white); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); transition: var(--transition); border: 1px solid var(--gray-200); }
.post-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
.post-card .post-body { padding: 24px; }
.post-card .post-date { font-size: .85rem; color: var(--gray-400); margin-bottom: 8px; }
.post-card h3 { margin-bottom: 12px; font-size: 1.15rem; }
.post-card h3 a { color: var(--dark); }
.post-card h3 a:hover { color: var(--primary); }
.post-card p { color: var(--gray-500); font-size: .95rem; }
.post-card .read-more { color: var(--primary); font-weight: 600; font-size: .9rem; }

/* ===== SPONSOR SECTION ===== */
.sponsor-tier { margin-bottom: 48px; }
.sponsor-tier h3 { text-align: center; margin-bottom: 24px; padding-bottom: 12px; border-bottom: 2px solid var(--gray-200); }
.sponsor-tier .sponsor-logos { display: flex; flex-wrap: wrap; gap: 32px; justify-content: center; align-items: center; }
.sponsor-tier .sponsor-logos a { display: block; padding: 16px; border-radius: var(--radius); border: 1px solid var(--gray-200); transition: var(--transition); background: var(--white); }
.sponsor-tier .sponsor-logos a:hover { border-color: var(--primary); box-shadow: var(--shadow); }
.sponsor-item { background: var(--white); border-radius: var(--radius); padding: 32px; border: 1px solid var(--gray-200); margin-bottom: 24px; }
.sponsor-item h4 { margin-bottom: 8px; }
.sponsor-item p { color: var(--gray-500); }

/* ===== LOCATION ===== */
.location-info { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.location-info .venue-details h3 { margin-bottom: 16px; }
.location-info .venue-details p { color: var(--gray-600); }
.venue-features { margin-top: 24px; }
.venue-features li { padding: 8px 0; color: var(--gray-600); display: flex; align-items: center; gap: 12px; }
.venue-features li::before { content: '\2713'; color: var(--primary); font-weight: 700; font-size: 1.1rem; }

/* ===== CONTACT FORM ===== */
.contact-form { max-width: 640px; margin: 0 auto; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 6px; font-weight: 600; color: var(--dark); font-size: .95rem; }
.form-group input, .form-group textarea, .form-group select { width: 100%; padding: 12px 16px; border: 2px solid var(--gray-200); border-radius: 8px; font-size: 1rem; font-family: var(--font); transition: var(--transition); background: var(--white); }
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(26,86,219,.1); }
.form-group textarea { min-height: 160px; resize: vertical; }

/* ===== FOOTER ===== */
.site-footer { background: var(--dark); color: var(--gray-400); padding: 64px 0 0; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 48px; }
.footer-col h4 { color: var(--white); margin-bottom: 20px; font-size: 1rem; }
.footer-col p { font-size: .9rem; line-height: 1.7; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul a { color: var(--gray-400); font-size: .9rem; }
.footer-col ul a:hover { color: var(--white); }
.footer-bottom { border-top: 1px solid var(--gray-700); padding: 24px 0; display: flex; justify-content: space-between; align-items: center; font-size: .85rem; }
.footer-bottom a { color: var(--gray-400); }
.footer-bottom a:hover { color: var(--white); }

/* ===== BREADCRUMBS ===== */
.breadcrumb { padding: 16px 0; font-size: .9rem; color: var(--gray-400); }
.breadcrumb a { color: var(--gray-500); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 8px; }

/* ===== PAGE HEADER ===== */
.page-header { background: linear-gradient(135deg, var(--dark) 0%, var(--primary-dark) 100%); color: var(--white); padding: 60px 0; text-align: center; }
.page-header h1 { margin-bottom: 12px; }
.page-header p { opacity: .8; font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* ===== AGENDA ===== */
.agenda-track { margin-bottom: 48px; }
.agenda-track h3 { margin-bottom: 24px; padding: 12px 20px; background: var(--primary); color: var(--white); border-radius: 8px; font-size: 1.1rem; }
.agenda-item { display: flex; gap: 20px; padding: 20px; border-left: 3px solid var(--primary); margin-bottom: 16px; background: var(--white); border-radius: 0 var(--radius) var(--radius) 0; box-shadow: var(--shadow); }
.agenda-item .time { font-weight: 700; color: var(--primary); min-width: 100px; font-size: .95rem; }
.agenda-item .details h4 { margin-bottom: 4px; }
.agenda-item .details p { color: var(--gray-500); font-size: .9rem; margin-bottom: 0; }

/* ===== LEGAL PAGES ===== */
.legal-content { max-width: 800px; margin: 0 auto; }
.legal-content h2 { font-size: 1.5rem; margin: 32px 0 12px; padding-top: 16px; border-top: 1px solid var(--gray-200); }
.legal-content h2:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.legal-content p, .legal-content li { color: var(--gray-600); font-size: .95rem; }
.legal-content ul { padding-left: 24px; margin-bottom: 16px; }
.legal-content ul li { list-style: disc; margin-bottom: 8px; }

/* ===== NEWSLETTER ===== */
.newsletter { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%); color: var(--white); padding: 64px 0; text-align: center; }
.newsletter h2 { color: var(--white); margin-bottom: 12px; }
.newsletter p { opacity: .85; margin-bottom: 24px; }
.newsletter-form { display: flex; gap: 12px; max-width: 480px; margin: 0 auto; }
.newsletter-form input { flex: 1; padding: 14px 20px; border: none; border-radius: 8px; font-size: 1rem; }
.newsletter-form button { padding: 14px 28px; background: var(--accent); color: var(--dark); border: none; border-radius: 8px; font-weight: 700; cursor: pointer; transition: var(--transition); }
.newsletter-form button:hover { background: var(--accent-hover); }

/* ===== VIDEO EMBED ===== */
.video-wrapper { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow-xl); }
.video-wrapper iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0; }

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .hero h1 { font-size: 2.25rem; }
  .hero { padding: 60px 0 50px; }
  .section { padding: 48px 0; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .location-info { grid-template-columns: 1fr; }
  .speaker-profile { flex-direction: column; align-items: center; text-align: center; }
  .nav-toggle { display: block; }
  .main-nav { display: none; position: absolute; top: 100%; left: 0; right: 0; background: var(--white); border-top: 1px solid var(--gray-200); box-shadow: var(--shadow-lg); padding: 16px; }
  .main-nav.open { display: block; }
  .main-nav ul { flex-direction: column; }
  .main-nav a { display: block; padding: 12px 16px; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
  .newsletter-form { flex-direction: column; }
  .hero .event-meta { flex-direction: column; gap: 12px; }
  .ticket-card .price { font-size: 2rem; }
}
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero h1 { font-size: 1.75rem; }
  .hero-cta { padding: 14px 28px; font-size: 1rem; }
}