/* NEXUS AI Subscription Button & Panel */
.chat-header-btn.nexus-sub-btn {
    width: auto;
    padding: 0 10px;
    gap: 5px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    font-weight: 600;
    position: relative;
}
.nexus-sub-text {
    color: inherit;
}
.nexus-sub-text.premium {
    color: #00ff88;
}
.nexus-sub-panel {
    position: fixed;
    top: 60px;
    right: 60px;
    width: 320px;
    background: rgba(10, 14, 23, 0.97);
    border: 1px solid rgba(0, 207, 255, 0.2);
    border-radius: 12px;
    z-index: 10000;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(20px);
    overflow: hidden;
}
.nexus-sub-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    border-bottom: 1px solid rgba(0, 150, 255, 0.12);
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    font-weight: 600;
    color: #00cfff;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.nexus-sub-close {
    background: none;
    border: none;
    color: #7B8794;
    font-size: 18px;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}
.nexus-sub-close:hover { color: #fff; }
.nexus-sub-panel-body {
    padding: 16px;
}
.nexus-sub-info {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.nexus-sub-tier-badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 6px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-align: center;
}
.nexus-sub-tier-badge.premium {
    background: rgba(0, 255, 136, 0.1);
    color: #00ff88;
    border: 1px solid rgba(0, 255, 136, 0.2);
}
.nexus-sub-tier-badge.payperuse {
    background: rgba(0, 207, 255, 0.1);
    color: #00cfff;
    border: 1px solid rgba(0, 207, 255, 0.2);
}
.nexus-sub-tier-badge.free {
    background: rgba(155, 163, 168, 0.1);
    color: #9DA3A8;
    border: 1px solid rgba(155, 163, 168, 0.2);
}
.nexus-sub-detail {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    color: #9DA3A8;
    font-family: 'JetBrains Mono', monospace;
}
.nexus-sub-detail span:last-child {
    color: #f9fafb;
    font-weight: 500;
}
.nexus-sub-note {
    font-size: 12px;
    color: #7B8794;
    line-height: 1.5;
    margin: 4px 0 0;
}
.nexus-sub-upgrade {
    margin-top: 8px;
    padding-top: 12px;
    border-top: 1px solid rgba(0, 150, 255, 0.08);
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.nexus-sub-price {
    font-family: 'JetBrains Mono', monospace;
    font-size: 28px;
    font-weight: 700;
    color: #00ff88;
    text-align: center;
    margin: 4px 0;
}
.nexus-sub-price span {
    font-size: 14px;
    color: #7B8794;
    font-weight: 400;
}
.nexus-sub-features {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.nexus-sub-features li {
    font-size: 12px;
    color: #9DA3A8;
    padding-left: 18px;
    position: relative;
}
.nexus-sub-features li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: #00ff88;
    font-weight: 700;
}
.nexus-sub-action-btn {
    display: block;
    width: 100%;
    padding: 12px;
    min-height: 44px;
    border: none;
    border-radius: 8px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    font-weight: 700;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    transition: all 0.2s;
}
.nexus-sub-action-btn.subscribe {
    background: #00ff88;
    color: #000;
}
.nexus-sub-action-btn.subscribe:hover {
    background: #00e67a;
    box-shadow: 0 0 16px rgba(0, 255, 136, 0.3);
}
.nexus-sub-action-btn.subscribe:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}
.nexus-sub-action-btn.cancel {
    background: transparent;
    color: #ff4444;
    border: 1px solid rgba(255, 68, 68, 0.3);
    margin-top: 4px;
}
.nexus-sub-action-btn.cancel:hover {
    background: rgba(255, 68, 68, 0.1);
}
.nexus-sub-warn {
    font-size: 11px;
    color: #ff4444;
    text-align: center;
    margin: 4px 0 0;
}
.nexus-sub-error {
    font-size: 12px;
    color: #ff4444;
    background: rgba(255, 68, 68, 0.08);
    border: 1px solid rgba(255, 68, 68, 0.2);
    border-radius: 6px;
    padding: 8px 10px;
    margin-top: 8px;
    text-align: center;
    font-family: 'JetBrains Mono', monospace;
}
.nexus-sub-loading {
    text-align: center;
    color: #7B8794;
    font-size: 13px;
    padding: 20px 0;
}
@media (max-width: 768px) {
    .nexus-sub-panel {
        right: 8px;
        width: calc(100vw - 16px);
        max-width: 320px;
    }
    .chat-header .nexus-sub-btn .nexus-sub-text {
        display: none;
    }
}