/* ===== AI智能问答抽屉 ===== */
.qa-fab {
    position: fixed;
    bottom: calc(1.5rem + env(safe-area-inset-bottom, 0px));
    right: var(--space-7);
    z-index: var(--z-dropdown);
}
.qa-fab-btn {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 50%;
    border: none;
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg), 0 4px 16px rgba(59, 130, 246, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    animation: qaFloat 3s ease-in-out infinite;
}
.qa-fab-btn:hover {
    transform: scale(1.12);
    box-shadow: var(--shadow-xl), 0 6px 20px rgba(59, 130, 246, 0.5);
}
@keyframes qaFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.qa-drawer-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 9998;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}
.qa-drawer-overlay.show {
    opacity: 1;
    visibility: visible;
}

.qa-drawer {
    position: fixed;
    top: 0;
    right: 0;
    width: min(420px, 90vw);
    max-width: 90vw;
    height: 100vh;
    background: var(--card-bg);
    box-shadow: var(--shadow-xl);
    z-index: 9999;
    transform: translateX(100%);
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
}
.qa-drawer.show {
    transform: translateX(0);
}

.qa-drawer-header {
    padding: var(--space-5) var(--space-6);
    border-bottom: 1px solid var(--card-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(29, 78, 216, 0.05));
}
.qa-drawer-title {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 1.1rem;
    font-weight: 700;
}
.qa-drawer-title .icon {
    font-size: 1.4rem;
}
.qa-drawer-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--content-text-secondary);
    padding: var(--space-3);
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
    transition: all 0.2s;
}
.qa-drawer-close:hover {
    background: var(--content-bg);
    color: var(--accent-red);
}

.qa-drawer-body {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-5) var(--space-6);
}

.qa-messages {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    margin-bottom: var(--space-5);
}

.qa-message {
    display: flex;
    gap: var(--space-2);
    animation: messageSlide 0.3s ease;
}
@keyframes messageSlide {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}
.qa-message.user {
    flex-direction: row-reverse;
}
.qa-message-avatar {
    width: var(--space-9);
    height: var(--space-9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    flex-shrink: 0;
}
.qa-message.user .qa-message-avatar {
    background: var(--accent-red);
    color: white;
}
.qa-message.ai .qa-message-avatar {
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: white;
}
.qa-message-content {
    max-width: 75%;
}
.qa-message.user .qa-message-content {
    text-align: right;
}
.qa-message-bubble {
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-2xl);
    font-size: 0.9rem;
    line-height: 1.6;
}
.qa-message.user .qa-message-bubble {
    background: var(--accent-red);
    color: white;
    border-bottom-right-radius: var(--radius-sm);
}
.qa-message.ai .qa-message-bubble {
    background: var(--content-bg);
    color: var(--content-text);
    border-bottom-left-radius: var(--radius-sm);
}

.qa-related {
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--card-border);
}
.qa-related-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--content-text-secondary);
    margin-bottom: var(--space-3);
}
.qa-related-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-2);
}
.qa-related-card {
    background: var(--content-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: var(--space-3);
    text-decoration: none;
    transition: all 0.2s;
    display: block;
}
.qa-related-card:hover {
    border-color: var(--accent-red);
    background: rgba(225, 29, 72, 0.04);
}
.qa-related-card-icon {
    font-size: 1.2rem;
    margin-bottom: var(--space-1);
}
.qa-related-card-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--content-text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.qa-related-card-tag {
    font-size: 0.7rem;
    color: var(--content-text-tertiary);
    margin-top: var(--space-1);
}

.qa-drawer-footer {
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--card-border);
    background: var(--card-bg);
}
.qa-input-group {
    display: flex;
    gap: var(--space-2);
    align-items: flex-end;
}
.qa-input {
    flex: 1;
    padding: var(--space-3) var(--space-4);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-full);
    font-size: 0.95rem;
    resize: none;
    max-height: 7.5rem;
    font-family: inherit;
    transition: all 0.2s;
    background: var(--content-bg);
    color: var(--content-text);
}
.qa-input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}
.qa-send-btn {
    width: var(--space-11);
    height: var(--space-11);
    border-radius: 50%;
    border: none;
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: white;
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}
.qa-send-btn:hover:not(:disabled) {
    transform: scale(1.08);
}
.qa-send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.qa-suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
}
.qa-suggestion {
    background: var(--content-bg);
    border: 1px solid var(--card-border);
    padding: var(--space-3) var(--space-4);
    min-height: 44px;
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--content-text-secondary);
}
.qa-suggestion:hover {
    border-color: #3b82f6;
    background: rgba(59, 130, 246, 0.06);
    color: #3b82f6;
}

.qa-loading {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    color: var(--content-text-secondary);
    font-size: 0.9rem;
}
.qa-loading-dots {
    display: flex;
    gap: var(--space-1);
}
.qa-loading-dots span {
    width: 0.375rem;
    height: 0.375rem;
    background: #3b82f6;
    border-radius: 50%;
    animation: qaBounce 1.4s infinite ease-in-out;
}
.qa-loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.qa-loading-dots span:nth-child(2) { animation-delay: -0.16s; }
@keyframes qaBounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

.qa-welcome {
    text-align: center;
    padding: var(--space-8) var(--space-4);
    color: var(--content-text-secondary);
}
.qa-welcome-icon {
    width: 4.5rem;
    height: 4.5rem;
    margin: 0 auto var(--space-4);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: transparent;
    background:
        radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.25) 0%, transparent 60%),
        linear-gradient(145deg, #fbbf24 0%, #ef4444 50%, #991b1b 100%);
    border: 2px solid rgba(255, 255, 255, 0.35);
    box-shadow:
        inset 0 2px 6px rgba(255, 255, 255, 0.35),
        inset 0 -2px 6px rgba(0, 0, 0, 0.15),
        0 0 0 3px rgba(239, 68, 68, 0.12),
        0 6px 18px rgba(153, 27, 27, 0.28),
        0 12px 28px rgba(220, 38, 38, 0.18);
    position: relative;
    animation: qaIconBreathe 3s ease-in-out infinite;
    will-change: transform, box-shadow;
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
                box-shadow 0.3s ease,
                filter 0.3s ease;
}
.qa-welcome-icon::before {
    content: "";
    width: 2rem;
    height: 2rem;
    background-image: url("data:image/svg+xml;base64,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");
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.2));
    z-index: 1;
}
.qa-welcome-icon::after {
    content: "";
    position: absolute;
    inset: -5px;
    border-radius: 50%;
    border: 1.5px solid rgba(251, 191, 36, 0.35);
    z-index: -1;
    animation: qaIconRing 3s ease-in-out infinite;
}
.qa-welcome-icon:hover {
    transform: translateY(-5px) scale(1.08);
    filter: brightness(1.05);
    box-shadow:
        inset 0 2px 6px rgba(255, 255, 255, 0.4),
        inset 0 -2px 6px rgba(0, 0, 0, 0.12),
        0 0 0 5px rgba(239, 68, 68, 0.16),
        0 10px 26px rgba(153, 27, 27, 0.32),
        0 18px 38px rgba(220, 38, 38, 0.24);
}
.qa-welcome-icon:hover::after {
    border-color: rgba(251, 191, 36, 0.55);
}
@keyframes qaIconBreathe {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.03); }
}
@keyframes qaIconRing {
    0%, 100% { transform: scale(1); opacity: 0.6; }
    50% { transform: scale(1.08); opacity: 0.25; }
}
.qa-welcome-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--content-text);
    margin-bottom: var(--space-2);
}
.qa-welcome-desc {
    font-size: 0.9rem;
    margin-bottom: var(--space-5);
}

/* 深色模式 */
body.dark .qa-drawer {
    background: #1a1a2e;
}
body.dark .qa-drawer-header {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.12), rgba(29, 78, 216, 0.08));
}
body.dark .qa-input {
    background: #252540;
    border-color: #333355;
    color: #e2e8f0;
}
body.dark .qa-suggestion {
    background: #252540;
    border-color: #333355;
    color: #94a3b8;
}
body.dark .qa-suggestion:hover {
    background: rgba(59, 130, 246, 0.15);
}

/* 移动端 */
@media (max-width: 480px) {
    .qa-drawer {
        width: 100vw;
    }
    .qa-fab {
        bottom: calc(6.25rem + env(safe-area-inset-bottom, 0px));
        right: var(--space-4);
    }
}