/* ================================================================
   Conference Proceedings Platform — Premium Design System v2.0
   Color palette: Deep Navy + Electric Blue + Crisp White
   ================================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Playfair+Display:wght@700;800&display=swap');

/* ── CSS Variables ─────────────────────────────────────────────── */
:root {
    --navy:         #0a1628;
    --navy-mid:     #0f2040;
    --navy-light:   #1a3358;
    --blue:         #2563eb;
    --blue-light:   #3b82f6;
    --blue-glow:    #60a5fa;
    --accent:       #06b6d4;   /* Cyan accent */
    --success:      #10b981;
    --warning:      #f59e0b;
    --danger:       #ef4444;

    --bg:           #f1f5f9;
    --bg-card:      #ffffff;
    --border:       #e2e8f0;
    --text:         #0f172a;
    --text-muted:   #64748b;
    --text-light:   #94a3b8;

    --radius-sm:    8px;
    --radius:       14px;
    --radius-lg:    20px;
    --radius-xl:    28px;

    --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
    --shadow:    0 4px 16px rgba(0,0,0,.08), 0 2px 6px rgba(0,0,0,.04);
    --shadow-lg: 0 20px 48px rgba(0,0,0,.12), 0 8px 20px rgba(0,0,0,.06);
    --shadow-blue: 0 8px 32px rgba(37,99,235,.25);

    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Base ──────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.65;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
}

/* ── Typography ────────────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
}
.display-serif { font-family: 'Playfair Display', serif; }

/* ── Navigation ────────────────────────────────────────────────── */
.navbar {
    background: rgba(10, 22, 40, 0.96) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255,255,255,.07);
    padding: 0.75rem 0;
    position: sticky;
    top: 0;
    z-index: 1030;
    transition: var(--transition);
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    font-size: 1.1rem;
    letter-spacing: -0.02em;
    color: #fff !important;
}

.navbar-brand .brand-logo {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    object-fit: cover;
}

.navbar-brand .brand-text { line-height: 1; }
.navbar-brand .brand-sub {
    font-size: 0.65rem;
    font-weight: 400;
    opacity: 0.6;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    display: block;
}

.nav-link {
    color: rgba(255,255,255,.75) !important;
    font-weight: 500;
    font-size: 0.875rem;
    padding: 0.5rem 0.85rem !important;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}
.nav-link:hover { color: #fff !important; background: rgba(255,255,255,.07); }
.nav-link.active { color: #fff !important; }

.navbar .btn-nav-cta {
    background: var(--blue);
    color: #fff !important;
    border-radius: var(--radius-sm);
    padding: 0.45rem 1rem !important;
    font-weight: 600;
    font-size: 0.875rem;
    border: none;
    transition: var(--transition);
}
.navbar .btn-nav-cta:hover {
    background: var(--blue-light);
    transform: translateY(-1px);
    box-shadow: var(--shadow-blue);
}

.dropdown-menu {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 0.5rem;
    min-width: 220px;
    animation: dropdownFade 0.2s ease;
}

@keyframes dropdownFade {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: translateY(0); }
}

.dropdown-item {
    border-radius: var(--radius-sm);
    padding: 0.6rem 0.875rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}
.dropdown-item:hover { background: var(--bg); color: var(--blue); }
.dropdown-divider { margin: 0.4rem 0; border-color: var(--border); }

/* ── Hero Section ──────────────────────────────────────────────── */
.hero-section {
    position: relative;
    min-height: 600px;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--navy) 0%, #0f2557 60%, #1a1063 100%);
    overflow: hidden;
}

.hero-bg-overlay {
    position: absolute; inset: 0;
    background-image: url('../img/hero_bg.png');
    background-size: cover;
    background-position: center;
    opacity: 0.12;
    filter: saturate(0.5);
}

.hero-particles {
    position: absolute; inset: 0;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(37,99,235,.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(6,182,212,.1) 0%, transparent 50%);
}

.hero-content { position: relative; z-index: 1; }

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(37,99,235,.15);
    border: 1px solid rgba(37,99,235,.3);
    color: var(--blue-glow);
    padding: 0.35rem 0.9rem;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 900;
    letter-spacing: -0.04em;
    line-height: 1.08;
    background: linear-gradient(135deg, #ffffff 0%, #93c5fd 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1.5rem;
}

.hero-lead {
    font-size: 1.1rem;
    color: rgba(255,255,255,.7);
    line-height: 1.7;
    max-width: 560px;
}

.hero-stats {
    display: flex;
    gap: 2.5rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,.1);
}

.hero-stat-num {
    font-size: 2rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -0.03em;
    line-height: 1;
}
.hero-stat-label {
    font-size: 0.78rem;
    color: rgba(255,255,255,.5);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
}

/* ── Cards ─────────────────────────────────────────────────────── */
.card {
    border: 1px solid var(--border) !important;
    border-radius: var(--radius) !important;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    background: var(--bg-card);
}

.card-hover:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37,99,235,.2) !important;
}

.glass-card {
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid rgba(255,255,255,.5) !important;
    border-radius: var(--radius-lg) !important;
    box-shadow: var(--shadow);
    transition: var(--transition);
}
.glass-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37,99,235,.25) !important;
}

/* ── Buttons ───────────────────────────────────────────────────── */
.btn-premium {
    background: linear-gradient(135deg, var(--blue) 0%, #1d4ed8 100%);
    color: #fff !important;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.65rem 1.5rem;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(37,99,235,.3);
    letter-spacing: 0.01em;
}
.btn-premium:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-blue);
    background: linear-gradient(135deg, var(--blue-light) 0%, var(--blue) 100%);
}
.btn-premium:active { transform: translateY(0); }

.btn-ghost {
    background: rgba(37,99,235,.08);
    color: var(--blue) !important;
    border: 1px solid rgba(37,99,235,.2);
    border-radius: var(--radius-sm);
    padding: 0.65rem 1.5rem;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition);
}
.btn-ghost:hover {
    background: rgba(37,99,235,.15);
    border-color: var(--blue);
    transform: translateY(-1px);
}

/* ── Feature section ───────────────────────────────────────────── */
.feature-icon {
    width: 52px; height: 52px;
    background: linear-gradient(135deg, rgba(37,99,235,.1) 0%, rgba(6,182,212,.1) 100%);
    border-radius: var(--radius);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.4rem;
    color: var(--blue);
    flex-shrink: 0;
    margin-bottom: 1rem;
    border: 1px solid rgba(37,99,235,.12);
}

/* ── Section Headers ───────────────────────────────────────────── */
.section-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--blue);
    margin-bottom: 0.75rem;
}

/* ── Badges & Status ───────────────────────────────────────────── */
.badge-status {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 0.3rem 0.75rem;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.02em;
}
.badge-status::before {
    content: '';
    width: 6px; height: 6px;
    border-radius: 50%;
    background: currentColor;
    animation: pulse 2s infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.status-active   { background: rgba(16,185,129,.1); color: #059669; }
.status-pending  { background: rgba(245,158,11,.1);  color: #d97706; }
.status-archived { background: rgba(100,116,139,.1); color: #64748b; }

/* ── Forms ─────────────────────────────────────────────────────── */
.form-control, .form-select {
    border-radius: var(--radius-sm);
    border: 1.5px solid var(--border);
    padding: 0.6rem 0.875rem;
    font-size: 0.9rem;
    transition: var(--transition);
    background: #fff;
}
.form-control:focus, .form-select:focus {
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgba(37,99,235,.12);
}
.form-label {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text);
    margin-bottom: 0.4rem;
}

/* ── Tables ────────────────────────────────────────────────────── */
.table { font-size: 0.9rem; }
.table th {
    font-weight: 600;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    border-bottom: 2px solid var(--border) !important;
    padding: 0.875rem 1rem;
    background: #f8fafc;
}
.table td { padding: 0.875rem 1rem; vertical-align: middle; }
.table-hover tbody tr:hover { background: rgba(37,99,235,.03); }

/* ── Dashboard Module Cards ────────────────────────────────────── */
.module-card {
    border-radius: var(--radius-lg) !important;
    border: 1px solid var(--border) !important;
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}
.module-card:hover { box-shadow: var(--shadow); transform: translateY(-3px); }

.module-card .module-header {
    padding: 1.25rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 0.95rem;
}

.module-card .module-header .module-icon {
    width: 38px; height: 38px;
    background: rgba(255,255,255,.2);
    border-radius: var(--radius-sm);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.1rem;
}

.module-card .module-body { padding: 1.25rem 1.5rem; background: #fff; }

/* ── Stat Cards ────────────────────────────────────────────────── */
.stat-card {
    border-radius: var(--radius-lg) !important;
    border: 1px solid var(--border) !important;
    padding: 1.5rem;
    background: #fff;
    text-align: center;
    transition: var(--transition);
}
.stat-card:hover { box-shadow: var(--shadow); transform: translateY(-4px); }
.stat-card .stat-value {
    font-size: 2.5rem;
    font-weight: 900;
    letter-spacing: -0.04em;
    line-height: 1;
}
.stat-card .stat-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-top: 0.4rem;
}

/* ── Alerts ────────────────────────────────────────────────────── */
.alert {
    border-radius: var(--radius);
    border: none;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 1rem 1.25rem;
}
.alert-success { background: rgba(16,185,129,.1); color: #065f46; }
.alert-warning { background: rgba(245,158,11,.1); color: #92400e; }
.alert-danger  { background: rgba(239,68,68,.1);  color: #991b1b; }
.alert-info    { background: rgba(37,99,235,.08); color: #1e40af; }

/* ── Breadcrumb ────────────────────────────────────────────────── */
.breadcrumb {
    font-size: 0.85rem;
    background: none;
    padding: 0;
    margin: 0;
}
.breadcrumb-item a { color: var(--blue); text-decoration: none; font-weight: 500; }
.breadcrumb-item a:hover { text-decoration: underline; }
.breadcrumb-item.active { color: var(--text-muted); }
.breadcrumb-item + .breadcrumb-item::before { color: var(--text-light); }

/* ── Footer ────────────────────────────────────────────────────── */
footer {
    background: var(--navy);
    color: rgba(255,255,255,.6);
    font-size: 0.875rem;
    padding: 3.5rem 0 2rem;
    margin-top: 5rem;
}
footer h6 {
    color: #fff;
    font-weight: 700;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 1.1rem;
}
footer a {
    color: rgba(255,255,255,.55);
    text-decoration: none;
    transition: var(--transition);
    display: block;
    margin-bottom: 0.5rem;
}
footer a:hover { color: #fff; padding-left: 4px; }
.footer-divider {
    border-color: rgba(255,255,255,.08);
    margin: 2rem 0 1.5rem;
}
.footer-brand {
    font-size: 1.1rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -0.02em;
}

/* ── Page Headers ──────────────────────────────────────────────── */
.page-header {
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 2.5rem 0;
    margin-bottom: 2.5rem;
}
.page-header h1 { font-size: 1.875rem; margin-bottom: 0.35rem; }

/* ── Loading Animation ─────────────────────────────────────────── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}
.animate-fade-in { animation: fadeInUp 0.6s ease-out forwards; }
.animate-delay-1 { animation-delay: 0.1s; opacity: 0; }
.animate-delay-2 { animation-delay: 0.2s; opacity: 0; }
.animate-delay-3 { animation-delay: 0.3s; opacity: 0; }

/* ── Scrollbar ─────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-light); }

/* ── Responsive ────────────────────────────────────────────────── */
@media (max-width: 768px) {
    .hero-section { padding: 4rem 0; min-height: auto; }
    .hero-title { font-size: 2rem; }
    .hero-stats { flex-wrap: wrap; gap: 1.5rem; }
}