/* ============================================================
   Unit Converter (单位换算) 页面样式
   ============================================================ */
.units-section {
    padding: 0 0 30px;
    border-bottom: 1px solid #eaeaea;
}

/* 分类 Tab 栏 */
.unit-category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.unit-tab {
    padding: 9px 18px;
    border: 1px solid #e3e6ea;
    border-radius: 999px;
    background: #f8f9fa;
    color: #555;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    line-height: 1.3;
}

.unit-tab:hover {
    border-color: #1a73e8;
    color: #1a73e8;
    background: #f1f8ff;
}

.unit-tab.active {
    background: #1a73e8;
    border-color: #1a73e8;
    color: #fff;
}

/* 分类分组：每组一个独立块（标签整行 + 按钮行） */
.unit-tab-group-wrap {
    flex-basis: 100%;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.unit-tab-group-wrap:not(:first-child) {
    margin-top: 6px;
}

/* 分组标签 */
.unit-tab-group {
    flex-basis: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 4px 0 0;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #9aa0a6;
}

.unit-tab-group::after {
    content: '';
    flex: 1;
    height: 1px;
    background: #eaeef2;
}

/* 分组下的按钮行（桌面：换行排列） */
.unit-tab-row {
    flex-basis: 100%;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

/* 换算输入区 */
.units-form {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 22px;
}

.unit-amount-input {
    flex: 1 1 200px;
    min-width: 160px;
}

.unit-amount-input input {
    width: 100%;
    padding: 13px 16px;
    border: 2px solid #e3e6ea;
    border-radius: 10px;
    font-size: 18px;
    font-weight: 600;
    color: #333;
    background: #fff;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    box-sizing: border-box;
}

.unit-amount-input input:focus {
    outline: none;
    border-color: #1a73e8;
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
}

.unit-select-wrapper {
    flex: 0 0 220px;
    min-width: 170px;
}

.unit-select {
    width: 100%;
    padding: 13px 16px;
    border: 2px solid #e3e6ea;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 500;
    color: #333;
    background: #fff;
    cursor: pointer;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    appearance: auto;
}

.unit-select:focus {
    outline: none;
    border-color: #1a73e8;
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
}

/* 快速开始预设按钮 */
.calc-presets {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
    margin: 0 0 14px;
}

.calc-preset-label {
    font-weight: 600;
    font-size: .85rem;
    color: #4b5563;
    margin-right: 4px;
}

.calc-preset-btn {
    font-size: .8rem;
    font-weight: 600;
    padding: .32rem .7rem;
    border-radius: 999px;
    border: 1px solid #cfe2fb;
    background: #fff;
    color: #1a73e8;
    cursor: pointer;
    transition: background .15s ease, border-color .15s ease, transform .1s ease;
}

.calc-preset-btn:hover {
    background: #eaf3ff;
    border-color: #1a73e8;
}

.calc-preset-btn:active {
    transform: scale(.96);
}

/* 结果区动态提示 */
.units-result-tip {
    margin: 0 0 10px;
    padding: 9px 14px;
    background: #f0f7ff;
    border-left: 4px solid #1a73e8;
    border-radius: 0 6px 6px 0;
    font-size: .88rem;
    color: #1a3d6e;
    line-height: 1.5;
}

/* 预设按钮点击后高亮目标换算行 */
.unit-result-row.preset-target {
    background: #fff7e6;
    border-color: #f5a623;
    box-shadow: 0 0 0 1px #f5a623 inset;
    animation: presetPulse 1.2s ease;
}

@keyframes presetPulse {
    0%, 100% { background: #fff7e6; }
    50% { background: #ffe8b8; }
}

/* 换算结果列表 */
.units-result {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 10px;
}

.unit-result-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 13px 16px;
    background: #f8f9fa;
    border: 1px solid #eef0f3;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
}

.unit-result-row:hover {
    background: #f1f8ff;
    border-color: #cfe2fb;
    transform: translateY(-1px);
}

.unit-result-row.active {
    background: #eaf3ff;
    border-color: #1a73e8;
    box-shadow: 0 0 0 1px #1a73e8 inset;
}

.unit-result-name {
    font-size: 13px;
    color: #555;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.unit-result-symbol {
    font-size: 11px;
    color: #9aa0a6;
}

.unit-result-value {
    font-size: 16px;
    font-weight: 700;
    color: #1a73e8;
    text-align: right;
    word-break: break-all;
}

/* 提示文案 */
.units-note {
    margin-top: 16px;
    font-size: 13px;
    color: #9aa0a6;
    line-height: 1.5;
}

/* 复制成功提示 */
.units-copy-toast {
    position: fixed;
    left: 50%;
    bottom: 90px;
    transform: translateX(-50%) translateY(20px);
    background: #333;
    color: #fff;
    padding: 10px 18px;
    border-radius: 8px;
    font-size: 13px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
    z-index: 999;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.units-copy-toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* 移动端适配 */
@media (max-width: 768px) {
    .units-section {
        padding: 0 0 24px;
    }

    /* 主内容卡片锁定为容器宽度，避免被换算器内部超宽内容撑出视口 */
    .container-home .main-content {
        width: 100%;
        max-width: 100%;
        min-width: 0;
    }

    .unit-category-tabs {
        display: block;               /* 阻断嵌套 flex min-content 把主内容撑宽 */
        width: 100%;
        min-width: 0;
        margin-bottom: 16px;
    }

    /* 每个分类分组改为块级：组标签整行 + 按钮行独立横向滚动 */
    .unit-tab-group-wrap {
        display: block;
        width: 100%;
        min-width: 0;
    }

    .unit-tab-group-wrap:not(:first-child) {
        margin-top: 10px;
    }

    .unit-tab-group {
        margin: 0 0 6px;
    }

    /* 分组下按钮单行横向滑动 */
    .unit-tab-row {
        flex-wrap: nowrap;            /* 禁止换行 */
        overflow-x: auto;             /* 开启横向滚动 */
        -webkit-overflow-scrolling: touch;
        scrollbar-width: thin;
        gap: 6px;
        padding-bottom: 8px;          /* 给滚动条留空间 */
    }

    .unit-tab-row::-webkit-scrollbar {
        height: 5px;
    }

    .unit-tab-row::-webkit-scrollbar-thumb {
        background: #d5dbe2;
        border-radius: 999px;
    }

    .unit-tab {
        flex: 0 0 auto;               /* 防止按钮被拉伸/收缩 */
        padding: 8px 14px;
        font-size: 13px;
    }

    .units-form {
        flex-direction: column;
        gap: 10px;
    }

    .unit-amount-input,
    .unit-select-wrapper {
        flex: 1 1 auto;
        width: 100%;
        min-width: 0;
    }

    .unit-amount-input input,
    .unit-select {
        padding: 12px 14px;
        font-size: 16px;
    }

    .units-result {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .unit-result-row {
        padding: 11px 14px;
    }

    .unit-result-value {
        font-size: 15px;
    }
}

/* 热门类别知识区 */
.unit-knowledge {
    margin-bottom: 24px;
    padding: 18px 0 4px;
    border-top: 1px solid #eaeaea;
}

.unit-knowledge h2 {
    font-size: 18px;
    margin: 0 0 14px;
}

.unit-knowledge-item {
    margin-bottom: 14px;
    padding: 14px 16px;
    background: #fff;
    border: 1px solid #e3e6ea;
    border-left: 3px solid #1a73e8;
    border-radius: 10px;
}

.unit-knowledge-item h3 {
    font-size: 14px;
    margin: 0 0 6px;
    color: #1a73e8;
}

.unit-knowledge-item p {
    margin: 0;
    font-size: 13.5px;
    line-height: 1.7;
    color: #555;
}