/* static/css/function_practice.css — 函数练习页面 */

* { box-sizing: border-box; }

body {
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    background: linear-gradient(135deg, #f6f8fa 0%, #eef2f6 100%);
    margin: 0;
    color: #2c3e50;
    line-height: 1.6;
    min-height: 100vh;
}

.fp-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 20px;
}

/* ───── 顶部 ───── */
.fp-header {
    background: #fff;
    border-radius: 16px;
    padding: 20px 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
    position: relative;
    overflow: hidden;
}
.fp-header::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 4px;
    background: linear-gradient(to right, #7b61ff, #5a43d0);
}
.fp-header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    flex-wrap: wrap;
    gap: 12px;
}
.fp-header h1 {
    margin: 0;
    font-size: 26px;
    color: #2c3e50;
}
.fp-header p {
    margin: 0;
    color: #666;
    font-size: 14px;
}
.fp-back {
    background: #6c757d;
    color: #fff;
    padding: 6px 14px;
    border-radius: 6px;
    text-decoration: none;
    font-size: 13px;
    transition: background 0.2s;
}
.fp-back:hover { background: #5a6268; color: #fff; }

/* ───── 工具栏 ───── */
.fp-toolbar {
    background: #fff;
    border-radius: 12px;
    padding: 14px 20px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}
.fp-label {
    font-weight: 600;
    color: #2c3e50;
}
.fp-select {
    padding: 6px 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    background: #fff;
    font-size: 14px;
    min-width: 160px;
    cursor: pointer;
}
.fp-hint {
    color: #888;
    font-size: 12px;
}
.fp-hint code {
    background: #f3f0ff;
    color: #5a43d0;
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 12px;
}

/* ───── 主体 grid ───── */
.fp-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 20px;
}
@media (max-width: 980px) {
    .fp-grid { grid-template-columns: 1fr; }
}

.fp-section-title {
    margin: 0 0 14px 0;
    font-size: 17px;
    color: #2c3e50;
}

/* ───── 左侧:函数参考 ───── */
.fp-refs {
    background: #fff;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
    max-height: calc(100vh - 220px);
    overflow-y: auto;
}
.fp-table-card {
    margin-bottom: 18px;
    border: 1px solid #eee;
    border-radius: 8px;
    overflow: hidden;
}
.fp-table-title {
    margin: 0;
    padding: 10px 14px;
    background: #f3f0ff;
    color: #5a43d0;
    font-size: 15px;
    border-bottom: 1px solid #eee;
}
.fp-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}
.fp-table th,
.fp-table td {
    padding: 8px 12px;
    text-align: left;
    border-bottom: 1px solid #f0f0f0;
    vertical-align: top;
}
.fp-table th {
    background: #fafbff;
    font-weight: 600;
    color: #555;
}
.fp-table tr:last-child td {
    border-bottom: none;
}
.fp-sig {
    font-family: "Consolas", "Monaco", monospace;
    color: #2c3e50;
    white-space: nowrap;
}
.fp-sig-fn {
    color: #5a43d0;
    font-weight: 700;
}
.fp-sig-arg {
    color: #999;
    font-style: italic;
}
.fp-desc {
    color: #555;
    line-height: 1.55;
}

/* ───── 右侧:输入输出 ───── */
.fp-io {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.fp-card {
    background: #fff;
    border-radius: 12px;
    padding: 16px 18px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}
.fp-input {
    width: 100%;
    font-family: "Consolas", "Monaco", monospace;
    font-size: 14px;
    padding: 12px 14px;
    border: 1px solid #ddd;
    border-radius: 8px;
    resize: vertical;
    background: #fafbff;
    color: #2c3e50;
    transition: border-color 0.2s, box-shadow 0.2s;
}
.fp-input:focus {
    outline: none;
    border-color: #7b61ff;
    box-shadow: 0 0 0 3px rgba(123, 97, 255, 0.15);
}

.fp-quick-row {
    margin-top: 10px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px;
}
.fp-quick-label {
    font-size: 12px;
    color: #888;
    margin-right: 4px;
}
.fp-quick-btn {
    background: #f3f0ff;
    color: #5a43d0;
    border: 1px solid #d6cfff;
    border-radius: 16px;
    padding: 3px 10px;
    font-size: 12px;
    font-family: "Consolas", "Monaco", monospace;
    cursor: pointer;
    transition: all 0.2s;
}
.fp-quick-btn:hover {
    background: #5a43d0;
    color: #fff;
    transform: translateY(-1px);
}

/* 输出框 */
.fp-output {
    margin-top: 8px;
    padding: 14px 16px;
    border-radius: 8px;
    font-family: "Consolas", "Monaco", monospace;
    font-size: 15px;
    border: 1px solid transparent;
    background: #fafbff;
    display: flex;
    align-items: center;
    gap: 10px;
    word-break: break-all;
    min-height: 48px;
}
.fp-output-label {
    color: #888;
    font-size: 13px;
    font-family: inherit;
}
.fp-output-value {
    font-weight: 600;
    color: #2c3e50;
    /* 保留连续空格 / 换行(Space(5) 会输出 5 个空格,
       默认 white-space: normal 会把多空格合并成一个) */
    white-space: pre-wrap;
    word-break: break-all;
}
.fp-output.ok {
    background: #e8f7ee;
    border-color: #b8e6c8;
}
.fp-output.ok .fp-output-value {
    color: #1e7e34;
}
.fp-output.err {
    background: #ffeaea;
    border-color: #f3b8b8;
}
.fp-output.err .fp-output-value {
    color: #b94a4a;
}
.fp-output.empty {
    background: #f5f5f5;
    border-color: #e0e0e0;
    color: #999;
}

/* 错误提示卡 */
.fp-err {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    background: #fff3f3;
    border: 1px solid #f3b8b8;
    border-left: 4px solid #e74c3c;
    border-radius: 8px;
    padding: 12px 14px;
    color: #b94a4a;
}
.fp-err-label { font-size: 18px; line-height: 1.2; }
.fp-err-text { font-size: 14px; line-height: 1.55; }

.fp-tip {
    background: #f3f0ff;
    border-radius: 8px;
    padding: 14px 18px;
    color: #555;
    font-size: 13px;
}
.fp-tip h3 {
    margin: 0 0 8px 0;
    color: #5a43d0;
    font-size: 14px;
}
.fp-tip ul {
    margin: 0;
    padding-left: 22px;
}
.fp-tip li { margin-bottom: 4px; }
.fp-tip code {
    background: #fff;
    color: #5a43d0;
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 12px;
}