/* ========== 斐波那契计算器 fibonacci-calculator ========== */

.fib-input {
    width: 100%;
    padding: 12px 14px;
    border: 1.5px solid var(--c-border);
    border-radius: 10px;
    background: var(--c-bg);
    color: var(--c-text);
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 18px;
    transition: border-color .15s, box-shadow .15s;
}
.fib-input:focus {
    outline: none;
    border-color: var(--c-primary);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--c-primary) 18%, transparent);
}

.fib-btn-row {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.fib-error {
    margin-bottom: 14px;
    padding: 10px 14px;
    border-radius: 10px;
    background: #fdecef;
    border: 1px solid #f3c2cf;
    color: #c0396b;
    font-size: 14px;
}

/* ---------- 结果卡片 ---------- */
.fib-result { display: flex; flex-direction: column; gap: 14px; }

.fib-card {
    border: 1px solid var(--c-border);
    border-radius: 14px;
    background: var(--c-card-bg, #fff);
    padding: 18px;
    box-shadow: 0 2px 10px rgba(30, 41, 59, .05);
}

.fib-card-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 12px;
}
.fib-k {
    font-size: 18px;
    font-weight: 800;
    color: var(--c-primary);
}
.fib-k sub { font-size: 12px; }

.fib-copy {
    border: 1px solid var(--c-border);
    background: var(--c-bg);
    color: var(--c-text-sub);
    border-radius: 8px;
    padding: 4px 10px;
    font-size: 12.5px;
    cursor: pointer;
    transition: all .15s;
}
.fib-copy:hover { border-color: var(--c-primary); color: var(--c-primary); }
.fib-copy.copied { border-color: #16a34a; color: #16a34a; background: #e7f8ee; }

/* ---------- 单项大数字 ---------- */
.fib-bignum {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 17px;
    line-height: 1.9;
    word-break: break-all;
    color: #7c3aed;
    background: #f6f2fe;
    border: 1px solid #e4d8fb;
    border-radius: 10px;
    padding: 12px 14px;
    font-variant-numeric: tabular-nums;
    user-select: all;
}
.fib-bignum em {
    display: block;
    text-align: center;
    font-style: normal;
    font-size: 12.5px;
    color: #b45309;
    background: #fef6e7;
    border-radius: 6px;
    padding: 3px 0;
    margin: 6px 0;
    user-select: none;
}

/* ---------- 指标 ---------- */
.fib-metrics {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-top: 14px;
}
.fib-metric {
    text-align: center;
    border-radius: 10px;
    background: var(--c-bg-soft, #f6f7fb);
    border: 1px solid var(--c-border);
    padding: 10px 6px;
}
.fib-metric b {
    display: block;
    font-size: 16px;
    color: var(--c-text);
    font-variant-numeric: tabular-nums;
    word-break: break-all;
}
.fib-metric span { font-size: 12px; color: var(--c-text-muted); }

/* ---------- 数列列表 ---------- */
.fib-list {
    list-style: none;
    margin: 0;
    padding: 0;
    max-height: 380px;
    overflow-y: auto;
    border: 1px solid var(--c-border);
    border-radius: 10px;
}
.fib-row {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding: 6px 12px;
    font-size: 13.5px;
}
.fib-row-alt { background: var(--c-bg-soft, #f8f9fd); }
.fib-idx {
    flex: 0 0 58px;
    color: var(--c-text-muted);
    font-variant-numeric: tabular-nums;
}
.fib-idx sub { font-size: 10px; }
.fib-val {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    word-break: break-all;
    color: var(--c-text);
}

.fib-detail {
    margin-top: 12px;
    border-top: 1px dashed var(--c-border);
    padding-top: 10px;
}
.fib-detail summary {
    cursor: pointer;
    font-size: 13.5px;
    font-weight: 600;
    color: var(--c-text-sub);
    list-style: none;
}
.fib-detail summary::before { content: '▸ '; color: var(--c-primary); }
.fib-detail[open] summary::before { content: '▾ '; }
.fib-lastnum {
    margin-top: 8px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 13px;
    line-height: 1.8;
    word-break: break-all;
    color: #7c3aed;
}
.fib-note { font-size: 12.5px; color: var(--c-text-muted); margin: 0 0 10px; }

/* ---------- 斐数判别 ---------- */
.fib-verdict {
    font-size: 16px;
    line-height: 1.8;
    padding: 14px 16px;
    border-radius: 10px;
    word-break: break-all;
}
.fib-verdict sub { font-size: 11px; }
.fib-verdict.fib-yes {
    background: #e7f8ee;
    border: 1px solid #b9e8cd;
    color: #15803d;
}
.fib-verdict.fib-no {
    background: #fdecef;
    border: 1px solid #f3c2cf;
    color: #c0396b;
}
.fib-neighbors {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 10px;
    margin-top: 12px;
}
.fib-nb {
    border: 1px solid var(--c-border);
    border-radius: 10px;
    padding: 10px;
    text-align: center;
    background: var(--c-bg-soft, #f8f9fd);
    min-width: 0;
}
.fib-nb span {
    display: block;
    font-size: 12px;
    color: var(--c-text-muted);
    margin-bottom: 4px;
}
.fib-nb b {
    display: block;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 13px;
    word-break: break-all;
    color: var(--c-text);
}
.fib-nb-cur {
    border-color: #7c3aed;
    background: #f6f2fe;
}
.fib-nb-cur b { color: #7c3aed; }
.fib-nb-empty { display: flex; align-items: center; justify-content: center; }

/* ---------- 黑夜模式 ---------- */
[data-theme="dark"] .fib-error {
    background: rgba(224, 68, 124, .13);
    border-color: rgba(224, 68, 124, .4);
    color: #ff7ab0;
}
[data-theme="dark"] .fib-bignum {
    background: rgba(124, 58, 237, .13);
    border-color: rgba(124, 58, 237, .4);
    color: #c4a6f7;
}
[data-theme="dark"] .fib-bignum em { background: rgba(180, 83, 9, .18); color: #fbbf24; }
[data-theme="dark"] .fib-lastnum { color: #c4a6f7; }
[data-theme="dark"] .fib-verdict.fib-yes { background: rgba(22, 163, 74, .15); border-color: rgba(22, 163, 74, .4); color: #4ede78; }
[data-theme="dark"] .fib-verdict.fib-no { background: rgba(224, 68, 124, .13); border-color: rgba(224, 68, 124, .4); color: #ff7ab0; }
[data-theme="dark"] .fib-nb-cur { background: rgba(124, 58, 237, .16); }

@media (max-width: 620px) {
    .fib-bignum { font-size: 14.5px; }
    .fib-metrics { grid-template-columns: 1fr; }
    .fib-neighbors { grid-template-columns: 1fr; }
}