/* ==========================================================================
   ChemLabX 4.0 — Landing page styles
   ========================================================================== */

.landing-bg {
    position: fixed;
    inset: 0;
    z-index: -2;
    pointer-events: none;
    background:
        radial-gradient(ellipse at 15% 30%, rgba(var(--accent-green-rgb),0.1) 0%, transparent 55%),
        radial-gradient(ellipse at 85% 15%, rgba(var(--accent-blue-rgb),0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 85%, rgba(var(--accent-purple-rgb),0.1) 0%, transparent 55%);
    animation: loginPulse 10s ease-in-out infinite alternate;
}
.landing-canvas {
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    opacity: 0.55;
}

.landing-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 22px 40px;
    position: relative;
    z-index: 2;
}
.landing-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 26px;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent-green), var(--accent-teal), var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.landing-logo .icon {
    font-size: 32px;
    -webkit-text-fill-color: initial;
    filter: drop-shadow(0 0 12px rgba(var(--accent-green-rgb),0.4));
}
.landing-logo .version {
    font-size: 11px;
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-pink));
    color: var(--on-bright);
    -webkit-text-fill-color: var(--on-bright);
    padding: 4px 12px;
    border-radius: 20px;
    font-weight: 700;
}
.landing-nav { display: flex; align-items: center; gap: 10px; }

.landing-hero {
    text-align: center;
    padding: 60px 24px 40px;
    position: relative;
    z-index: 1;
}
.hero-badge {
    display: inline-block;
    background: rgba(var(--accent-purple-rgb),0.12);
    border: 1px solid rgba(var(--accent-purple-rgb),0.3);
    color: var(--accent-purple);
    font-size: 13px;
    font-weight: 700;
    padding: 8px 20px;
    border-radius: 40px;
    margin-bottom: 24px;
}
.hero-title {
    font-size: clamp(34px, 6vw, 64px);
    font-weight: 900;
    line-height: 1.25;
    margin-bottom: 20px;
}
.hero-title .grad {
    background: linear-gradient(135deg, var(--accent-green), var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-sub {
    color: var(--text-secondary);
    font-size: 16px;
    max-width: 640px;
    margin: 0 auto 32px;
    line-height: 1.9;
}
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn-lg { padding: 16px 34px; font-size: 16px; border-radius: 16px; }

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 48px;
}
.stat {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 18px 30px;
    min-width: 140px;
    backdrop-filter: blur(20px);
}
.stat-value {
    font-size: 28px;
    font-weight: 900;
    font-family: var(--font-mono);
    background: linear-gradient(135deg, var(--accent-green), var(--accent-blue));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-label { font-size: 12px; color: var(--text-secondary); margin-top: 4px; }

.landing-section {
    padding: 60px 40px;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}
.section-head {
    font-size: 28px;
    font-weight: 900;
    text-align: center;
    margin-bottom: 40px;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-green));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}
.feature-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 28px;
    backdrop-filter: blur(20px);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}
.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-green), var(--accent-blue), var(--accent-purple));
    opacity: 0;
    transition: opacity 0.3s;
}
.feature-card:hover { transform: translateY(-6px); border-color: var(--border-accent); box-shadow: var(--shadow-glow); }
.feature-card:hover::before { opacity: 1; }
.feature-icon { font-size: 40px; margin-bottom: 16px; }
.feature-card h3 { font-size: 17px; font-weight: 800; margin-bottom: 10px; }
.feature-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.8; }

.roles-section { padding-top: 20px; }
.roles-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}
.role-card {
    border-radius: 20px;
    padding: 26px;
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    transition: var(--transition);
}
.role-card:hover { transform: translateY(-6px) scale(1.02); box-shadow: var(--shadow-glow); }
.role-admin:hover { border-color: var(--accent-red); }
.role-teacher:hover { border-color: var(--accent-blue); }
.role-student:hover { border-color: var(--accent-green); }
.role-user:hover { border-color: var(--accent-purple); }
.role-icon { font-size: 38px; margin-bottom: 12px; }
.role-card h3 { font-size: 17px; font-weight: 800; margin-bottom: 8px; }
.role-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.8; }

.landing-cta {
    text-align: center;
    padding: 60px 24px;
    position: relative;
    z-index: 1;
}
.landing-cta h2 { font-size: 34px; font-weight: 900; margin-bottom: 12px; }
.landing-cta p { color: var(--text-secondary); margin-bottom: 28px; }

.landing-footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-primary);
    border-top: 1px solid var(--glass-border);
    position: relative;
    z-index: 1;
    font-size: 14px;
}
.landing-footer .muted { color: var(--text-secondary); font-size: 12px; margin-top: 6px; }

@media (max-width: 900px) {
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .roles-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
    .feature-grid { grid-template-columns: 1fr; }
    .roles-grid { grid-template-columns: 1fr; }
    .landing-header { padding: 16px 18px; flex-wrap: wrap; gap: 10px; }
    .landing-logo { font-size: 20px; gap: 8px; }
    .landing-logo .icon { font-size: 24px; }
    .landing-nav { gap: 6px; flex-wrap: wrap; }
    .landing-nav .btn-sm { padding: 8px 12px; font-size: 12px; }
    .landing-section { padding: 40px 18px; }
    .hero-stats { flex-direction: column; align-items: center; }
    .stat { width: 100%; max-width: 240px; }
}