/* ======= 函数图像生成器 专属样式（共享类在 style.css，这里只写专属部件） ======= */

/* ---------- 整体：控件在上，画布在下（全宽） ---------- */
.fg-tool-wrapper {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.fg-btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
}

.fg-checkbox {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    cursor: pointer;
    user-select: none;
}

.fg-checkbox input {
    accent-color: var(--primary-color);
    cursor: pointer;
}

/* ---------- 面板 ---------- */
.fg-panel {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.875rem;
    background: var(--bg-secondary);
}

.fg-panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.fg-panel-title {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.92rem;
    font-weight: 600;
    color: var(--text-primary);
}

.fg-panel-title i {
    color: var(--primary-color);
}

/* ---------- 常用函数快捷按钮 ---------- */
.fg-preset-label {
    font-size: 0.78rem;
    color: var(--text-secondary);
    margin: 0 0 0.45rem;
}

.fg-presets {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    margin-bottom: 0.875rem;
}

.fg-preset {
    display: inline-flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.05rem;
    padding: 0.35rem 0.6rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-primary);
    cursor: pointer;
    line-height: 1.3;
    transition: all 0.15s ease;
}

.fg-preset:hover {
    border-color: var(--primary-color);
    background: var(--primary-light);
    transform: translateY(-1px);
}

.fg-preset:active {
    transform: translateY(0);
}

.fg-preset-name {
    font-size: 0.72rem;
    color: var(--text-secondary);
}

.fg-preset-expr {
    font-family: 'Courier New', monospace;
    font-size: 0.82rem;
    color: var(--primary-color);
    font-weight: 600;
}

/* ---------- 函数列表 ---------- */
.fg-func-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.fg-func-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.fg-func-row {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto auto auto;
    align-items: center;
    gap: 0.4rem;
    padding: 0.25rem 0.375rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: border-color 0.2s ease;
}

.fg-func-row:focus-within {
    border-color: var(--primary-color);
}

.fg-func-row.fg-row-error {
    border-color: var(--danger-color);
}

.fg-color-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    flex: none;
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.6) inset;
}

.fg-expr-input {
    width: 100%;
    min-width: 0;
    border: none;
    background: transparent;
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    padding: 0.3rem 0.1rem;
    outline: none;
}

.fg-expr-input::placeholder {
    color: var(--text-secondary);
    font-family: inherit;
}

.fg-func-status {
    display: inline-flex;
    align-items: center;
    font-size: 0.85rem;
    line-height: 1;
}

.fg-status-ok {
    color: var(--success-color);
}

.fg-status-err {
    color: var(--danger-color);
}

.fg-func-visible {
    position: relative;
    display: inline-flex;
    align-items: center;
    cursor: pointer;
    color: var(--text-secondary);
}

.fg-func-visible input {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    margin: 0;
    cursor: pointer;
}

.fg-func-visible i {
    font-size: 0.95rem;
    transition: color 0.2s ease, opacity 0.2s ease;
}

.fg-func-visible input:not(:checked) + i {
    opacity: 0.35;
}

.fg-func-visible input:checked + i {
    color: var(--primary-color);
}

.fg-func-remove {
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.15rem 0.25rem;
    border-radius: var(--radius-sm);
    line-height: 1;
    transition: all 0.2s ease;
}

.fg-func-remove:hover {
    color: var(--danger-color);
    background: rgba(255, 77, 79, 0.1);
}

.fg-func-err {
    display: none;
    font-size: 0.75rem;
    color: var(--danger-color);
    padding-left: 1.6rem;
    line-height: 1.4;
}

.fg-empty {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    padding: 0.75rem 0.25rem;
    margin: 0;
}

/* ---------- 参数 + 分析（并排） ---------- */
.fg-mid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr);
    gap: 1rem;
    align-items: start;
}

.fg-param-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.fg-param-row .form-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.88rem;
    margin-bottom: 0.25rem;
}

.fg-param-row .form-label span {
    font-family: 'Courier New', monospace;
    font-weight: 700;
    color: var(--text-primary);
}

.fg-param-row .form-label b {
    color: var(--primary-color);
    font-family: 'Courier New', monospace;
}

.fg-range {
    width: 100%;
    accent-color: var(--primary-color);
    cursor: pointer;
}

.fg-tangent-row {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px dashed var(--border-color);
}

.fg-tangent-row .form-label {
    font-size: 0.85rem;
    margin: 0;
    white-space: nowrap;
}

.fg-tangent-input {
    width: 100%;
    min-width: 0;
    padding: 0.35rem 0.5rem;
    font-size: 0.85rem;
}

.fg-analysis {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    max-height: 240px;
    overflow-y: auto;
}

.fg-sec h4 {
    margin: 0 0 0.35rem;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-primary);
    padding-bottom: 0.2rem;
    border-bottom: 1px solid var(--border-color);
}

.fg-sec-line {
    display: flex;
    align-items: baseline;
    gap: 0.35rem;
    flex-wrap: wrap;
    font-size: 0.78rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.fg-sec-line b {
    color: var(--text-primary);
    font-weight: 600;
}

.fg-sec-line code {
    font-family: 'Courier New', monospace;
    color: var(--text-primary);
    word-break: break-all;
}

.fg-sec-line.fg-none {
    color: var(--text-secondary);
    font-style: italic;
}

.fg-dot {
    display: inline-block;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    flex: none;
    align-self: center;
}

/* ---------- 画布区（全宽） ---------- */
.fg-canvas-section {
    min-width: 0;
}

.fg-canvas-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 0.75rem;
}

.fg-view-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.fg-action-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.fg-action-buttons .btn {
    width: auto;
}

.fg-canvas-wrap {
    position: relative;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    background: var(--bg-primary);
    box-shadow: 0 1px 3px var(--shadow-color);
}

#fgCanvas {
    display: block;
    width: 100%;
    height: auto;
    cursor: grab;
    touch-action: none;
}

#fgCanvas.fg-grabbing {
    cursor: grabbing;
}

.fg-hover-readout {
    position: absolute;
    top: 0.5rem;
    left: 0.5rem;
    max-width: calc(100% - 1rem);
    padding: 0.3rem 0.6rem;
    background: rgba(45, 140, 240, 0.92);
    color: #fff;
    font-size: 0.78rem;
    font-family: 'Courier New', monospace;
    border-radius: var(--radius-sm);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    opacity: 0;
    transform: translateY(-4px);
    transition: opacity 0.15s ease, transform 0.15s ease;
    pointer-events: none;
}

.fg-hover-readout.show {
    opacity: 1;
    transform: translateY(0);
}

.fg-canvas-hint {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    margin-top: 0.6rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.fg-canvas-hint i {
    color: var(--primary-color);
}

/* ---------- 语法速查表 ---------- */
.fg-table-wrap {
    margin-top: 0.75rem;
    overflow-x: auto;
}

.fg-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

.fg-table th,
.fg-table td {
    padding: 0.625rem 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
    vertical-align: top;
}

.fg-table th {
    background: var(--primary-light);
    color: var(--text-primary);
    font-weight: 600;
}

.fg-table td {
    color: var(--text-secondary);
}

.fg-table td code {
    font-family: 'Courier New', monospace;
    background: var(--code-bg);
    padding: 0.05rem 0.3rem;
    border-radius: var(--radius-sm);
    color: var(--primary-color);
    white-space: nowrap;
}

.fg-table tbody tr:nth-child(even) td {
    background: var(--bg-light);
}

/* ---------- Toast 变体（.toast 本体在 style.css） ---------- */
.toast.success {
    background-color: var(--success-color);
    color: #fff;
}

.toast.error {
    background-color: var(--danger-color);
    color: #fff;
}

/* ---------- 响应式 ---------- */
@media (max-width: 992px) {
    .fg-mid {
        grid-template-columns: 1fr;
    }

    .fg-analysis {
        max-height: 300px;
    }
}

@media (max-width: 768px) {
    .fg-canvas-toolbar {
        flex-direction: column;
        align-items: stretch;
    }

    .fg-view-actions,
    .fg-action-buttons {
        width: 100%;
    }

    .fg-action-buttons .btn {
        flex: 1 1 auto;
        justify-content: center;
    }

    .fg-preset {
        flex: 1 1 calc(50% - 0.4rem);
        align-items: center;
    }

    .fg-expr-input {
        font-size: 0.85rem;
    }

    .fg-func-row {
        grid-template-columns: auto minmax(0, 1fr) auto auto;
    }

    .fg-func-status {
        display: none;
    }
}

@media (max-width: 480px) {
    .fg-tangent-row {
        grid-template-columns: 1fr;
    }

    .fg-preset {
        flex: 1 1 100%;
    }
}