/* ============================================================================
 * 电阻计算器 · 样式
 * ========================================================================== */

:root {
  --bg: #f4f6f9;
  --bg-soft: #eaeef4;
  --panel: #ffffff;
  --text: #141922;
  --muted: #6b7280;
  --muted-2: #9ca3af;
  --border: #e3e8ef;
  --border-strong: #cdd5e0;
  --accent: #2563eb;
  --accent-ink: #ffffff;
  --accent-soft: #eef4ff;
  --ok: #067a55;
  --ok-soft: #e7f7f1;
  --warn: #a45c07;
  --warn-soft: #fdf3e3;
  --err: #c02626;
  --err-soft: #fdecec;
  --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 6px 20px rgba(16, 24, 40, .06);
  --radius: 14px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

html[data-theme="dark"] {
  --bg: #0f1319;
  --bg-soft: #151b23;
  --panel: #181f28;
  --text: #e8edf5;
  --muted: #98a2b3;
  --muted-2: #6b7684;
  --border: #26303c;
  --border-strong: #36414f;
  --accent: #5b8cff;
  --accent-ink: #0b1220;
  --accent-soft: #17233a;
  --ok: #4ade9f;
  --ok-soft: #12291f;
  --warn: #f0b45e;
  --warn-soft: #2a2113;
  --err: #ff8080;
  --err-soft: #2c1618;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font: 15px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  -webkit-font-smoothing: antialiased;
  padding-bottom: 64px;
}

/* ------------------------------------------------------------------ 顶栏 */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px clamp(16px, 4vw, 40px) 16px;
  max-width: 1080px;
  margin: 0 auto;
}

.brand { display: flex; align-items: center; gap: 14px; }

.logo {
  width: 44px; height: 44px;
  flex: 0 0 44px;
  display: grid; place-items: center;
  border-radius: 12px;
  background: linear-gradient(145deg, var(--accent), #7c3aed);
  color: #fff;
  font: 700 22px/1 var(--mono);
  box-shadow: var(--shadow);
}

.brand h1 { margin: 0; font-size: 19px; letter-spacing: .2px; }
.brand .sub { margin: 2px 0 0; font-size: 12.5px; color: var(--muted); }

/* ------------------------------------------------------------------ 标签页 */
.tabs {
  display: flex;
  gap: 6px;
  padding: 0 clamp(16px, 4vw, 40px);
  max-width: 1080px;
  margin: 0 auto 18px;
  overflow-x: auto;
  scrollbar-width: none;
}
.tabs::-webkit-scrollbar { display: none; }

.tab {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--muted);
  font: 500 14px/1 inherit;
  padding: 10px 16px;
  border-radius: 999px;
  cursor: pointer;
  transition: all .15s ease;
  white-space: nowrap;
}
.tab:hover { border-color: var(--border-strong); color: var(--text); }
.tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  box-shadow: var(--shadow);
}

/* ------------------------------------------------------------------ 布局 */
main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 40px);
  display: grid;
  gap: 16px;
}

.panel { display: none; gap: 16px; }
.panel.active { display: grid; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}

.card h2 {
  margin: 0 0 14px;
  font-size: 14px;
  font-weight: 650;
  letter-spacing: .3px;
  color: var(--muted);
  text-transform: uppercase;
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}
.card-head h2 { margin: 0; }

/* ------------------------------------------------------------------ 分段控件 */
.seg {
  display: inline-flex;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 3px;
  gap: 3px;
}
.seg button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: 500 13.5px/1 inherit;
  padding: 8px 13px;
  border-radius: 7px;
  cursor: pointer;
  transition: all .14s ease;
}
.seg button:hover { color: var(--text); }
.seg button.active {
  background: var(--panel);
  color: var(--text);
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(16, 24, 40, .12);
}

/* ------------------------------------------------------------------ 电阻外观 */
.resistor-wrap {
  display: flex;
  justify-content: center;
  padding: 18px 8px 22px;
  overflow-x: auto;
}

.resistor { display: flex; align-items: center; }

.lead {
  width: clamp(34px, 9vw, 84px);
  height: 5px;
  background: linear-gradient(180deg, #d7dee8, #94a3b8 55%, #7c8798);
  flex: 0 0 auto;
}
.lead.l { border-radius: 3px 0 0 3px; }
.lead.r { border-radius: 0 3px 3px 0; }

.body {
  position: relative;
  display: flex;
  align-items: center;
  gap: 11px;
  height: 58px;
  padding: 0 22px;
  border-radius: 30px;
  background: linear-gradient(180deg, #f6ead0 0%, #e2cf9f 45%, #cbb27c 78%, #bda469 100%);
  box-shadow:
    inset 0 -7px 14px rgba(90, 62, 20, .28),
    inset 0 7px 12px rgba(255, 255, 255, .62),
    0 8px 20px rgba(16, 24, 40, .2);
}

.band {
  width: 13px;
  height: 100%;
  border-radius: 3px;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .22);
  flex: 0 0 auto;
  transition: transform .14s ease, box-shadow .14s ease;
}
.body.interactive .band { cursor: pointer; }
.body.interactive .band:hover { transform: scaleX(1.18); }
.band.selected {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.body .spacer { flex: 1 1 auto; min-width: 12px; }

.resistor.small .body { height: 42px; padding: 0 16px; gap: 8px; border-radius: 22px; }
.resistor.small .band { width: 10px; }
.resistor.small .lead { width: 40px; height: 4px; }

/* ------------------------------------------------------------------ 环选择器 */
.band-pickers {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  margin-top: 4px;
}

.band-picker {
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 10px 12px;
  background: var(--bg-soft);
  cursor: pointer;
  transition: border-color .14s ease, background .14s ease;
}
.band-picker:hover { border-color: var(--border-strong); }
.band-picker.active {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.band-picker .bp-label {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  font-size: 12px; color: var(--muted); margin-bottom: 7px;
}
.band-picker .bp-label b { color: var(--text); font-weight: 600; font-size: 12.5px; }
.bp-row { display: flex; align-items: center; gap: 8px; }

.swatch {
  width: 22px; height: 22px;
  flex: 0 0 22px;
  border-radius: 6px;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .25);
}
.swatch.none {
  background: repeating-linear-gradient(45deg, #dfe4ea 0 5px, #f7f9fc 5px 10px);
}
html[data-theme="dark"] .swatch.none {
  background: repeating-linear-gradient(45deg, #2b3542 0 5px, #1c242e 5px 10px);
}

.bp-row select {
  flex: 1 1 auto;
  min-width: 0;
  font: inherit;
  font-size: 13.5px;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 8px;
  cursor: pointer;
}

/* ------------------------------------------------------------------ 调色板 */
.palette-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 12px; flex-wrap: wrap;
  margin: 20px 0 10px;
  font-size: 13.5px;
}
.palette-head b { font-size: 14px; }
.palette-head .hint { color: var(--muted-2); font-size: 12.5px; }

.palette {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(auto-fill, minmax(78px, 1fr));
}

.chip {
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 11px;
  padding: 7px 6px 8px;
  cursor: pointer;
  display: grid;
  justify-items: center;
  gap: 6px;
  font: inherit;
  color: var(--text);
  transition: all .14s ease;
}
.chip:hover { border-color: var(--border-strong); transform: translateY(-1px); }
.chip.active { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }
.chip .dot {
  width: 30px; height: 30px; border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .28);
}
.chip .dot.none { background: repeating-linear-gradient(45deg, #dfe4ea 0 5px, #f7f9fc 5px 10px); }
html[data-theme="dark"] .chip .dot.none { background: repeating-linear-gradient(45deg, #2b3542 0 5px, #1c242e 5px 10px); }
.chip .cn { font-size: 12.5px; font-weight: 600; line-height: 1.2; }
.chip .cv { font-size: 11px; color: var(--muted); font-family: var(--mono); }
.chip:disabled { opacity: .28; cursor: not-allowed; transform: none; }

/* ------------------------------------------------------------------ 结果 */
.result-card { padding: 20px; }

.result-main {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}
.result-value {
  font: 700 clamp(30px, 7vw, 46px)/1.1 var(--mono);
  letter-spacing: -1px;
}
.result-value .unit { font-size: .52em; font-weight: 600; color: var(--muted); margin-left: 6px; }
.result-value.bad { color: var(--err); font-size: 22px; font-family: inherit; font-weight: 600; }
.result-sub { color: var(--muted); font-size: 13.5px; font-family: var(--mono); }

.stat-grid {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  margin-top: 18px;
}
.stat {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 10px 12px;
}
.stat .k { font-size: 11.5px; color: var(--muted); letter-spacing: .3px; }
.stat .v { font-size: 15px; font-weight: 600; font-family: var(--mono); margin-top: 3px; word-break: break-all; }

.msg-list { display: grid; gap: 8px; margin-top: 16px; }
.msg {
  display: flex; gap: 9px; align-items: flex-start;
  border-radius: 10px; padding: 10px 12px; font-size: 13.5px;
  border: 1px solid transparent;
}
.msg .ico { flex: 0 0 auto; font-weight: 700; }
.msg.err { background: var(--err-soft); color: var(--err); border-color: color-mix(in srgb, var(--err) 25%, transparent); }
.msg.warn { background: var(--warn-soft); color: var(--warn); border-color: color-mix(in srgb, var(--warn) 25%, transparent); }
.msg.ok { background: var(--ok-soft); color: var(--ok); border-color: color-mix(in srgb, var(--ok) 25%, transparent); }

.band-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.band-tag {
  display: inline-flex; align-items: center; gap: 7px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 12px 5px 6px;
  font-size: 13px;
}
.band-tag .dot { width: 15px; height: 15px; border-radius: 50%; box-shadow: inset 0 0 0 1px rgba(0,0,0,.25); }
.band-tag .dot.none { background: repeating-linear-gradient(45deg,#dfe4ea 0 4px,#f7f9fc 4px 8px); }
.band-tag em { font-style: normal; color: var(--muted); font-family: var(--mono); font-size: 12px; }

/* ------------------------------------------------------------------ 表单 */
.row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: flex-end;
}

.field { display: grid; gap: 6px; flex: 1 1 180px; min-width: 0; }
.field > span { font-size: 12.5px; color: var(--muted); font-weight: 500; }

input, select, textarea {
  font: inherit;
  font-size: 14.5px;
  color: var(--text);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  width: 100%;
  transition: border-color .14s ease, box-shadow .14s ease;
}
input { font-family: var(--mono); }
input:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
select { cursor: pointer; font-family: inherit; }

.btn {
  font: 600 14px/1 inherit;
  background: var(--accent);
  color: var(--accent-ink);
  border: 1px solid var(--accent);
  border-radius: 10px;
  padding: 11px 20px;
  cursor: pointer;
  transition: filter .14s ease, transform .14s ease;
  white-space: nowrap;
}
.btn:hover { filter: brightness(1.07); }
.btn:active { transform: translateY(1px); }

.ghost-btn {
  font: 500 13px/1 inherit;
  background: var(--panel);
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 15px;
  cursor: pointer;
  transition: all .14s ease;
}
.ghost-btn:hover { border-color: var(--border-strong); color: var(--text); }

.quick { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 12px; }
.quick button {
  font: 500 12.5px/1 var(--mono);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: 999px;
  padding: 6px 12px;
  cursor: pointer;
  transition: all .14s ease;
}
.quick button:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }

/* ------------------------------------------------------------------ 图例 */
.legend { overflow-x: auto; }
.legend table { width: 100%; border-collapse: collapse; font-size: 13px; min-width: 520px; }
.legend th, .legend td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
}
.legend th { color: var(--muted); font-weight: 600; font-size: 12px; }
.legend tr:last-child td { border-bottom: 0; }
.legend .lg-name { display: flex; align-items: center; gap: 8px; font-weight: 600; }
.legend .lg-name .dot { width: 16px; height: 16px; border-radius: 4px; box-shadow: inset 0 0 0 1px rgba(0,0,0,.25); }
.legend .lg-name .dot.none { background: repeating-linear-gradient(45deg,#dfe4ea 0 4px,#f7f9fc 4px 8px); }
.legend code { font-family: var(--mono); font-size: 12.5px; color: var(--muted); }

/* ------------------------------------------------------------------ 串并联行 */
.combine-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 9px;
}
.combine-row .idx {
  flex: 0 0 26px;
  font: 600 12px/1 var(--mono);
  color: var(--muted-2);
  text-align: right;
}
.combine-row input { flex: 1 1 auto; }
.combine-row .del {
  flex: 0 0 auto;
  width: 34px; height: 34px;
  border-radius: 9px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--muted);
  font-size: 17px;
  line-height: 1;
  cursor: pointer;
}
.combine-row .del:hover { border-color: var(--err); color: var(--err); }

footer {
  max-width: 1080px;
  margin: 26px auto 0;
  padding: 0 clamp(16px, 4vw, 40px);
  color: var(--muted-2);
  font-size: 12px;
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

@media (max-width: 560px) {
  .brand .sub { display: none; }
  .card { padding: 15px; }
  .result-card { padding: 16px; }
}