/* Left Sidebar Styles */
.sidebar-left {
    padding: var(--spacing-lg) var(--spacing-md);
}

/* ===== Nút tạo hội thoại mới ===== */
.new-chat-btn {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    background: var(--color-gradient);
    color: white;
    padding: 14px var(--spacing-md);
    border-radius: var(--radius-md);
    font-family: var(--font-display);
    font-weight: 700;
    font-size: var(--font-size-base);
    letter-spacing: 0.3px;
    margin-bottom: var(--spacing-lg);
    box-shadow: 0 4px 14px rgba(0, 85, 170, 0.35);
    transition: box-shadow 0.2s, transform 0.12s, filter 0.2s;
}

.new-chat-btn:hover {
    filter: brightness(1.05);
    box-shadow: 0 6px 20px rgba(0, 85, 170, 0.45);
    transform: translateY(-1px);
}

.new-chat-btn:active {
    transform: translateY(0);
    box-shadow: 0 3px 10px rgba(0, 85, 170, 0.35);
}

.new-chat-btn svg {
    flex-shrink: 0;
}

/* ===== Tiêu đề khu lịch sử ===== */
.history-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0 var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: var(--font-size-caption);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-ink-lighter);
}

.history-header svg {
    flex-shrink: 0;
    opacity: 0.8;
}

/* ===== Danh sách lịch sử ===== */
.history-list {
    flex-grow: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 3px;
    margin-bottom: var(--spacing-md);
    padding-right: 2px;
}

.history-list::-webkit-scrollbar {
    width: 6px;
}

.history-list::-webkit-scrollbar-thumb {
    background-color: var(--color-border);
    border-radius: var(--radius-round);
}

.history-item {
    position: relative;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px var(--spacing-md) 10px var(--spacing-sm);
    border-radius: var(--radius-sm);
    color: var(--color-ink-light);
    font-size: var(--font-size-base);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: background-color 0.18s, color 0.18s;
    text-align: left;
    border: 1px solid transparent;
}

/* Icon bong bóng chat trước mỗi mục lịch sử */
.history-item .history-icon {
    flex-shrink: 0;
    color: var(--color-ink-lighter);
    opacity: 0.7;
    transition: color 0.18s, opacity 0.18s;
}

.history-item .history-text {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.history-item:hover {
    background-color: var(--color-surface-hover);
    color: var(--color-ink);
}

.history-item:hover .history-icon {
    opacity: 1;
    color: var(--color-ink-light);
}

/* Mục đang chọn — nền nổi + thanh nhấn màu bên trái */
.history-item.active {
    background-color: var(--color-surface-hover);
    color: var(--color-ink);
    font-weight: 600;
    border-color: var(--color-border);
}

.history-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    border-radius: var(--radius-round);
    background: var(--color-primary);
}

.history-item.active .history-icon {
    opacity: 1;
    color: var(--color-primary);
}

/* Trạng thái rỗng khi chưa có lịch sử */
.history-empty {
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    color: var(--color-ink-lighter);
    font-size: var(--font-size-caption);
    line-height: 1.6;
}

.history-empty svg {
    display: block;
    margin: 0 auto var(--spacing-sm);
    opacity: 0.4;
}

.sidebar-footer {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.icon-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-ink-light);
    border-radius: var(--radius-sm);
    transition: background-color 0.2s, color 0.2s;
}

.icon-btn:hover {
    background-color: var(--color-border);
    color: var(--color-ink);
}

.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-ink-light);
}

/* Toggle Switch */
.switch {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-border);
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
}

input:checked + .slider {
    background-color: var(--color-primary);
}

input:checked + .slider:before {
    transform: translateX(20px);
}

.slider.round {
    border-radius: 24px;
}

.slider.round:before {
    border-radius: 50%;
}