/* ============================================================
   fridge-defrost · 冰箱除霜与耗电
   冰晶霜室风（fdf-）：冰蓝 + 霜白 + 深海蓝，霜花/冷冻室搁架/滑块冰条装饰
   与快递面单 / 防护盾牌 / 宣纸卷轴等主题零重叠
   ============================================================ */
.fdf-page {
    --fdf-ice: #3a9bd9;
    --fdf-ice-deep: #1c5f8f;
    --fdf-ice-soft: rgba(58, 155, 217, 0.12);
    --fdf-frost: #eaf4fb;
    --fdf-card: #fdfeff;
    --fdf-card-2: #eff6fb;
    --fdf-line: #cfdeea;
    --fdf-line-strong: #a3bdd2;
    --fdf-text: #14293a;
    --fdf-muted: #5b7488;
    --fdf-warn: #d97b2f;
    --fdf-warn-soft: rgba(217, 123, 47, 0.10);
    --fdf-shadow: 0 6px 20px rgba(28, 95, 143, 0.12);

    color: var(--fdf-text);
    font-size: 15px;
    line-height: 1.8;
}

[data-theme="dark"] .fdf-page {
    --fdf-ice: #6cb4e0;
    --fdf-ice-deep: #8fc8ea;
    --fdf-ice-soft: rgba(108, 180, 224, 0.14);
    --fdf-frost: #14222e;
    --fdf-card: #182833;
    --fdf-card-2: #1f3442;
    --fdf-line: #2e4657;
    --fdf-line-strong: #476279;
    --fdf-text: #ddeaf3;
    --fdf-muted: #8ca3b5;
    --fdf-warn: #e69c5c;
    --fdf-warn-soft: rgba(230, 156, 92, 0.14);
    --fdf-shadow: 0 6px 20px rgba(0, 0, 0, 0.45);
}

.fdf-page h1, .fdf-page h2, .fdf-page h3 { line-height: 1.4; }
.fdf-page b, .fdf-page strong { color: var(--fdf-ice-deep); }

/* ---------- 首屏：霜室 ---------- */
.fdf-hero {
    position: relative;
    display: grid;
    grid-template-columns: minmax(0, 1.5fr) minmax(180px, 0.65fr) minmax(240px, 0.85fr);
    gap: 22px 26px;
    align-items: center;
    padding: 30px 32px 26px;
    margin-bottom: 24px;
    border-radius: 18px;
    border: 1px solid var(--fdf-line-strong);
    background:
        radial-gradient(circle at 8% 0%, var(--fdf-ice-soft) 0, transparent 34%),
        linear-gradient(180deg, var(--fdf-frost) 0%, var(--fdf-card) 100%);
    box-shadow: var(--fdf-shadow);
    overflow: hidden;
}
/* 顶部霜檐 */
.fdf-hero::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 12px;
    background: linear-gradient(180deg, var(--fdf-ice) 0%, transparent 100%);
    opacity: 0.25;
}
.fdf-kicker {
    display: inline-block;
    padding: 5px 14px;
    margin-bottom: 12px;
    border-radius: 999px;
    background: var(--fdf-ice);
    color: #fff;
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.18em;
}
.fdf-hero h1 { margin: 0 0 10px; font-size: clamp(25px, 3.2vw, 36px); font-weight: 900; }
.fdf-hero-sub { margin: 0 0 14px; max-width: 56ch; color: var(--fdf-muted); font-size: 15px; }
.fdf-hero-chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 0; padding: 0; list-style: none; }
.fdf-hero-chips li {
    padding: 5px 13px;
    border-radius: 8px;
    border: 1px solid var(--fdf-line-strong);
    background: var(--fdf-card);
    color: var(--fdf-muted);
    font-size: 12px;
    font-weight: 700;
}

/* hero 冷冻室 */
.fdf-hero-frost {
    display: grid;
    justify-items: center;
    gap: 10px;
}
.fdf-frost-box {
    position: relative;
    width: 150px; height: 150px;
    border: 3px solid var(--fdf-ice-deep);
    border-radius: 12px;
    background: linear-gradient(180deg, var(--fdf-card-2) 0%, var(--fdf-card) 100%);
    overflow: hidden;
    box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.5), 0 10px 22px rgba(28, 95, 143, 0.22);
}
.fdf-frost-shelf {
    position: absolute;
    left: 10px; right: 10px; top: 42px;
    height: 6px;
    border-radius: 3px;
    background: var(--fdf-line-strong);
    box-shadow: 0 3px 0 var(--fdf-ice-soft);
}
.fdf-frost-shelf--2 { top: 92px; }
.fdf-snow {
    position: absolute;
    top: 6px; left: 0; right: 0;
    text-align: center;
    font-size: 13px;
    letter-spacing: 0.5em;
    color: var(--fdf-ice);
    opacity: 0.8;
}
.fdf-flake {
    position: absolute;
    color: var(--fdf-ice);
    opacity: 0.85;
    animation: fdf-fall 4.5s linear infinite;
}
.fdf-flake--1 { left: 18%; font-size: 14px; animation-delay: 0s; }
.fdf-flake--2 { left: 52%; font-size: 11px; animation-delay: 1.6s; }
.fdf-flake--3 { left: 80%; font-size: 13px; animation-delay: 3s; }
@keyframes fdf-fall {
    0% { transform: translateY(-14px); opacity: 0; }
    15% { opacity: 0.85; }
    100% { transform: translateY(130px); opacity: 0; }
}
.fdf-frost-caption {
    padding: 5px 14px;
    border-radius: 999px;
    border: 1px dashed var(--fdf-ice);
    background: var(--fdf-card);
    color: var(--fdf-ice-deep);
    font-size: 12px;
    font-weight: 800;
}

/* hero 读数 */
.fdf-hero-readout, .fdf-result-hero {
    padding: 18px 20px;
    border-radius: 14px;
    border: 1px solid var(--fdf-line-strong);
    background: var(--fdf-card);
    display: grid;
    gap: 4px;
    justify-items: start;
    box-shadow: var(--fdf-shadow);
}
.fdf-hero-readout { position: relative; z-index: 1; }
.fdf-readout-label, .fdf-rh-label {
    font-size: 12px;
    font-weight: 800;
    letter-spacing: 0.18em;
    color: var(--fdf-muted);
}
.fdf-readout-num, .fdf-rh-num {
    font-size: 27px;
    font-weight: 900;
    color: var(--fdf-ice-deep);
    font-variant-numeric: tabular-nums;
    line-height: 1.3;
}
.fdf-readout-state { font-size: 13px; font-weight: 700; color: var(--fdf-warn); }
.fdf-readout-meta { font-size: 12px; color: var(--fdf-muted); }
.fdf-readout-tip { margin-top: 6px; font-size: 12px; color: var(--fdf-muted); opacity: 0.85; }

/* ---------- 主体两栏 ---------- */
.fdf-calc {
    display: grid;
    grid-template-columns: minmax(0, 1.55fr) minmax(290px, 1fr);
    gap: 20px;
    align-items: start;
    margin-bottom: 28px;
}
.fdf-input-col { display: grid; gap: 16px; min-width: 0; }

.fdf-panel {
    padding: 20px 22px;
    border: 1px solid var(--fdf-line);
    border-radius: 14px;
    background: var(--fdf-card);
    box-shadow: var(--fdf-shadow);
}
.fdf-panel-head { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.fdf-panel-head h2 { margin: 0; font-size: 18px; font-weight: 800; }
.fdf-panel-head p { margin: 2px 0 0; font-size: 13px; color: var(--fdf-muted); }
.fdf-step {
    flex-shrink: 0;
    width: 38px; height: 38px;
    display: grid;
    place-items: center;
    border-radius: 10px;
    background: var(--fdf-ice);
    color: #fff;
    font-size: 15px;
    font-weight: 900;
}
.fdf-step--cold { background: var(--fdf-ice-deep); }
.fdf-step--warn { background: var(--fdf-warn); font-size: 17px; }

.fdf-grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.fdf-field { display: grid; gap: 6px; }
.fdf-label { font-size: 13px; font-weight: 700; color: var(--fdf-text); }
.fdf-label small { font-weight: 500; color: var(--fdf-muted); font-size: 11.5px; margin-left: 4px; }
.fdf-input-wrap, .fdf-select-wrap { position: relative; display: flex; align-items: center; }
.fdf-select-wrap::after {
    content: "▾";
    position: absolute;
    right: 12px;
    color: var(--fdf-muted);
    font-size: 13px;
    pointer-events: none;
}
.fdf-input {
    width: 100%;
    height: 44px;
    padding: 0 12px;
    border: 1.5px solid var(--fdf-line-strong);
    border-radius: 10px;
    background: var(--fdf-card-2);
    color: var(--fdf-text);
    font-size: 15px;
    font-weight: 700;
    outline: none;
    transition: border-color 0.15s, box-shadow 0.15s;
    appearance: none;
    -webkit-appearance: none;
}
.fdf-select-wrap .fdf-input { padding-right: 30px; }
.fdf-input:focus { border-color: var(--fdf-ice); box-shadow: 0 0 0 3px var(--fdf-ice-soft); }
.fdf-input:disabled { opacity: 0.5; cursor: not-allowed; }

/* ---------- 霜厚滑块 ---------- */
.fdf-slider-block {
    margin-top: 14px;
    padding: 16px 18px;
    border: 1px dashed var(--fdf-line-strong);
    border-radius: 12px;
    background: var(--fdf-card-2);
}
.fdf-slider-block.is-disabled { opacity: 0.55; }
.fdf-slider-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; }
.fdf-thick-val {
    font-size: 20px;
    font-weight: 900;
    color: var(--fdf-ice-deep);
    font-variant-numeric: tabular-nums;
}
.fdf-slider {
    width: 100%;
    height: 10px;
    margin: 14px 0 6px;
    appearance: none;
    -webkit-appearance: none;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--fdf-ice) var(--fdf-fill, 20%), var(--fdf-line) var(--fdf-fill, 20%));
    outline: none;
    cursor: pointer;
}
.fdf-slider::-webkit-slider-thumb {
    appearance: none;
    -webkit-appearance: none;
    width: 24px; height: 24px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 30%, #fff 0 28%, var(--fdf-ice) 29%);
    border: 2px solid var(--fdf-ice-deep);
    box-shadow: 0 2px 8px rgba(28, 95, 143, 0.35);
    cursor: grab;
}
.fdf-slider::-moz-range-thumb {
    width: 22px; height: 22px;
    border-radius: 50%;
    background: radial-gradient(circle at 35% 30%, #fff 0 28%, var(--fdf-ice) 29%);
    border: 2px solid var(--fdf-ice-deep);
    box-shadow: 0 2px 8px rgba(28, 95, 143, 0.35);
    cursor: grab;
}
.fdf-slider:disabled { cursor: not-allowed; }
.fdf-slider-scale {
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    color: var(--fdf-muted);
}
.fdf-slider-hint { margin: 8px 0 0; font-size: 12.5px; color: var(--fdf-muted); }

.fdf-error {
    margin-top: 12px;
    padding: 10px 14px;
    border-radius: 8px;
    border: 1px solid rgba(217, 123, 47, 0.4);
    background: var(--fdf-warn-soft);
    color: var(--fdf-warn);
    font-size: 13px;
}
.fdf-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.fdf-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 44px;
    padding: 0 20px;
    border: 1.5px solid var(--fdf-line-strong);
    border-radius: 10px;
    background: var(--fdf-card-2);
    color: var(--fdf-text);
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.12s, box-shadow 0.12s;
}
.fdf-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 10px rgba(28, 95, 143, 0.16); }
.fdf-btn:disabled { opacity: 0.55; cursor: not-allowed; transform: none; }
.fdf-btn--primary {
    border-color: var(--fdf-ice-deep);
    background: linear-gradient(170deg, var(--fdf-ice) 0%, var(--fdf-ice-deep) 100%);
    color: #fff;
}

/* ---------- 除霜六步 ---------- */
.fdf-panel--steps { border-left: 4px solid var(--fdf-ice); }
.fdf-steps { margin: 0; padding: 0; list-style: none; counter-reset: fdfstep; display: grid; gap: 10px; }
.fdf-steps li {
    position: relative;
    padding: 12px 14px 12px 46px;
    border: 1px solid var(--fdf-line);
    border-radius: 10px;
    background: var(--fdf-card-2);
    font-size: 13.5px;
    counter-increment: fdfstep;
}
.fdf-steps li::before {
    content: counter(fdfstep);
    position: absolute;
    left: 12px; top: 11px;
    width: 24px; height: 24px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--fdf-ice);
    color: #fff;
    font-size: 13px;
    font-weight: 900;
}
.fdf-steps-note {
    margin: 12px 0 0;
    padding: 10px 14px;
    border-radius: 8px;
    background: var(--fdf-ice-soft);
    border-left: 3px solid var(--fdf-ice);
    font-size: 13px;
    color: var(--fdf-text);
}

/* ---------- 风险卡 ---------- */
.fdf-panel--risk { border-left: 4px solid var(--fdf-warn); }
.fdf-risk-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.fdf-risk-card {
    padding: 16px;
    border: 1px solid var(--fdf-line);
    border-radius: 12px;
    background: var(--fdf-card-2);
}
.fdf-risk-card h3 { margin: 0 0 6px; font-size: 14.5px; font-weight: 800; }
.fdf-risk-card p { margin: 0; font-size: 13px; color: var(--fdf-muted); }

/* ---------- 结果列 ---------- */
.fdf-result-col { display: grid; gap: 14px; position: sticky; top: 16px; }
.fdf-rh-sub { font-size: 13px; font-weight: 700; color: var(--fdf-ice); }

.fdf-kpis { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.fdf-kpi {
    padding: 12px 14px;
    border: 1px solid var(--fdf-line);
    border-radius: 12px;
    background: var(--fdf-card);
    display: grid;
    gap: 2px;
}
.fdf-kpi span { font-size: 12px; color: var(--fdf-muted); font-weight: 700; }
.fdf-kpi b { font-size: 21px; font-weight: 900; color: var(--fdf-text); line-height: 1.2; font-variant-numeric: tabular-nums; }
.fdf-kpi small { font-size: 11px; color: var(--fdf-muted); }

.fdf-mini-card {
    padding: 16px 18px;
    border: 1px solid var(--fdf-line);
    border-radius: 12px;
    background: var(--fdf-card);
}
.fdf-mini-card h3 { margin: 0 0 10px; font-size: 15px; font-weight: 800; color: var(--fdf-ice-deep); }
.fdf-advice { font-size: 13.5px; color: var(--fdf-muted); }
.fdf-advice b { color: var(--fdf-ice-deep); }
.fdf-advice .fdf-advice-warn { color: var(--fdf-warn); }
.fdf-result-foot { margin: 0; font-size: 12px; color: var(--fdf-muted); }

/* ---------- 对比表 ---------- */
.fdf-vs { margin-bottom: 28px; }
.fdf-section-head { margin: 0 0 14px; }
.fdf-section-kicker {
    display: inline-block;
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 0.2em;
    color: var(--fdf-ice-deep);
    opacity: 0.85;
}
.fdf-section-head h2 { margin: 4px 0 2px; font-size: 22px; font-weight: 900; }
.fdf-section-head p { margin: 0; font-size: 13px; color: var(--fdf-muted); }
.fdf-vs-table-wrap {
    border: 1px solid var(--fdf-line-strong);
    border-radius: 12px;
    overflow: hidden;
    background: var(--fdf-card);
    box-shadow: var(--fdf-shadow);
}
.fdf-vs-table { width: 100%; border-collapse: collapse; }
.fdf-vs-table th, .fdf-vs-table td {
    padding: 11px 16px;
    border-bottom: 1px solid var(--fdf-line);
    font-size: 13.5px;
    text-align: left;
    vertical-align: top;
}
.fdf-vs-table thead th {
    background: linear-gradient(170deg, var(--fdf-ice) 0%, var(--fdf-ice-deep) 100%);
    color: #fff;
    font-size: 12.5px;
    font-weight: 800;
    letter-spacing: 0.06em;
    white-space: nowrap;
}
.fdf-vs-table tbody tr:nth-child(even) { background: var(--fdf-card-2); }
.fdf-vs-table tbody tr:last-child td { border-bottom: none; }
.fdf-vs-table td { color: var(--fdf-muted); }
.fdf-vs-table td b { color: var(--fdf-text); }

/* ---------- 省电清单 ---------- */
.fdf-save { margin-bottom: 28px; }
.fdf-save-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.fdf-save-card {
    padding: 16px 18px;
    border: 1px solid var(--fdf-line);
    border-radius: 12px;
    background: var(--fdf-card);
    box-shadow: var(--fdf-shadow);
}
.fdf-save-card h3 { margin: 0 0 6px; font-size: 15px; font-weight: 800; }
.fdf-save-card p { margin: 0; font-size: 13px; color: var(--fdf-muted); }

/* ---------- FAQ ---------- */
.fdf-faq { margin-bottom: 28px; }
.fdf-faq .faq-item { border-color: var(--fdf-line); background: var(--fdf-card); }
.fdf-faq .faq-item summary { color: var(--fdf-text); }
.fdf-faq .faq-a { color: var(--fdf-muted); }
.fdf-comments { margin-bottom: 28px; }

/* ---------- 返回顶部 ---------- */
.fdf-top {
    position: fixed;
    right: 22px;
    bottom: 26px;
    width: 44px; height: 44px;
    border: none;
    border-radius: 12px;
    background: linear-gradient(170deg, var(--fdf-ice) 0%, var(--fdf-ice-deep) 100%);
    color: #fff;
    font-size: 18px;
    font-weight: 900;
    cursor: pointer;
    opacity: 0;
    pointer-events: none;
    transform: translateY(8px);
    transition: opacity 0.2s, transform 0.2s;
    box-shadow: 0 6px 16px rgba(28, 95, 143, 0.3);
    z-index: 60;
}
.fdf-top.show { opacity: 1; pointer-events: auto; transform: translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
    .fdf-hero { grid-template-columns: 1fr 1fr; }
    .fdf-hero-readout { grid-column: 1 / -1; }
    .fdf-calc { grid-template-columns: 1fr; }
    .fdf-result-col { position: static; }
    .fdf-save-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 720px) {
    .fdf-hero { grid-template-columns: 1fr; padding: 22px 18px; }
    .fdf-grid3 { grid-template-columns: 1fr; }
    .fdf-risk-grid { grid-template-columns: 1fr; }
    .fdf-save-grid { grid-template-columns: 1fr; }
    .fdf-actions .fdf-btn { flex: 1 1 46%; }
}