/* ===== 螺栓拧紧力计算工具 V5 ===== */

:root {
  --bg: #f1f3f8;
  --card: #ffffff;
  --bd: #e6eaf2;
  --bd-soft: #f0f2f7;
  --text: #1a2233;
  --text-soft: #4a5772;
  --muted: #8893a8;
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-soft: rgba(99, 102, 241, .08);
  --primary-glow: rgba(99, 102, 241, .14);
  --accent: #a855f7;
  --radius: 14px;
  --rs: 10px;
  --shadow-sm: 0 1px 3px rgba(20, 30, 50, .05);
  --shadow-md: 0 6px 24px rgba(20, 30, 50, .07);
  --shadow-lg: 0 16px 48px rgba(79, 70, 229, .28);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(168, 85, 247, .09), transparent 60%),
    radial-gradient(900px 500px at 0% 100%, rgba(99, 102, 241, .08), transparent 60%),
    var(--bg);
  color: var(--text);
  font: 14px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* ===== 顶栏 ===== */
.topbar {
  position: sticky; top: 0; z-index: 30;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--bd);
  padding: 12px 18px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { margin: 0; font-size: 16px; font-weight: 600; letter-spacing: .2px; }
.logo {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px;
  background: linear-gradient(135deg, #6366f1, #a855f7);
  color: #fff; border-radius: 9px;
  font-size: 18px; font-weight: 700; line-height: 1;
  box-shadow: 0 6px 14px rgba(99, 102, 241, .38);
}
.reset-btn {
  background: #fff; color: var(--text-soft);
  border: 1px solid var(--bd);
  padding: 5px 14px; border-radius: 999px;
  font-size: 12px; cursor: pointer; font-family: inherit;
  transition: all .15s;
}
.reset-btn:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ===== 容器 ===== */
.container {
  max-width: 720px; margin: 0 auto;
  padding: 18px 16px;
  display: flex; flex-direction: column; gap: 14px;
}

/* ===== 卡片 ===== */
.card {
  background: var(--card);
  border: 1px solid var(--bd);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s, transform .2s;
}
.card:hover { box-shadow: var(--shadow-md); }
.card h2 {
  margin: 0; font-size: 14px; font-weight: 600; color: var(--text);
  display: flex; align-items: center;
  letter-spacing: .2px;
}
.card h2::before {
  content: ""; width: 4px; height: 14px; border-radius: 2px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
  margin-right: 10px;
}
.card-head {
  margin-bottom: 14px; display: flex; align-items: center; justify-content: space-between;
  gap: 12px;
}
.collapsible-head { cursor: pointer; user-select: none; padding: 4px 0; }
.collapsible-head h2 { pointer-events: none; }

/* ===== 表单 ===== */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.field {
  display: flex; flex-direction: column; gap: 6px;
  margin-bottom: 12px;
  min-width: 0;
}
.field:last-child { margin-bottom: 0; }
.lbl {
  font-size: 12px; font-weight: 500; color: var(--text-soft);
  display: flex; justify-content: space-between; align-items: baseline;
  gap: 8px;
}
.lbl .src {
  font-size: 11px; font-weight: 400; color: var(--muted);
  font-family: "Cambria Math", "Consolas", monospace;
}
.ctrl {
  width: 100%; padding: 9px 12px;
  font-size: 14px; font-family: inherit;
  border: 1px solid var(--bd); border-radius: var(--rs);
  background: #fff; color: var(--text);
  outline: none; transition: all .15s;
}
.ctrl:hover { border-color: #cbd2e0; }
.ctrl:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--primary-glow);
}
.ctrl[readonly] { background: #f7f9fc; color: var(--text-soft); }
.ctrl[disabled] {
  background: #f3f5fa; color: #a8b1c2;
  border-color: var(--bd-soft);
}

select.ctrl {
  appearance: none; padding-right: 30px; cursor: pointer;
  background: #fff url("data:image/svg+xml;charset=UTF-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='none' stroke='%238893a8' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round' d='M3 4.5l3 3 3-3'/%3E%3C/svg%3E") no-repeat right 10px center;
  transition: background-color .15s;
}
select.ctrl:hover { background-color: #fafbfd; }

/* ===== 数据 chips ===== */
.chips, .chip-row { display: flex; gap: 8px; margin-top: 4px; flex-wrap: wrap; }
.chip {
  flex: 1; min-width: 90px;
  background: linear-gradient(135deg, #f7f9fc, #eef2f8);
  border: 1px solid var(--bd-soft);
  border-radius: var(--rs);
  padding: 8px 12px;
  display: flex; align-items: baseline; gap: 7px;
}
.chip em {
  font-style: normal; font-size: 11px; color: var(--muted);
  font-family: "Cambria Math", serif;
}
.chip b {
  font-size: 14px; font-weight: 600;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
  font-family: "Cambria Math", "Consolas", monospace;
}

/* ===== 分割线 ===== */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--bd), transparent);
  margin: 18px 0 6px;
}

/* ===== 折叠 (胶囊按钮) ===== */
.caret {
  font-size: 14px; color: var(--muted);
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px;
  border-radius: 999px;
  background: var(--bd-soft);
  transition: transform .25s, background .15s, color .15s;
}
.collapsible-head:hover .caret {
  background: var(--primary-soft); color: var(--primary);
}
.collapsible.collapsed .caret { transform: rotate(-90deg); }

.collapsible-body {
  max-height: 1400px; overflow: hidden;
  transition: max-height .3s ease, opacity .25s, margin-top .25s;
  opacity: 1;
  margin-top: 14px;
}
.collapsible.collapsed .collapsible-body {
  max-height: 0; opacity: 0; margin-top: 0; pointer-events: none;
}

/* ===== 相斥勾选项 (radio-card) ===== */
.seg-radios {
  display: grid; grid-template-columns: 1fr 1fr; gap: 10px;
  margin-bottom: 14px;
}
.radio-card {
  display: flex; gap: 10px;
  padding: 12px 14px;
  background: #fafbfd;
  border: 1.5px solid var(--bd);
  border-radius: var(--rs);
  cursor: pointer;
  transition: all .15s;
  position: relative;
}
.radio-card:hover { border-color: #cbd2e0; background: #fff; }
.radio-card input { position: absolute; opacity: 0; pointer-events: none; }
.rc-radio {
  flex-shrink: 0;
  width: 18px; height: 18px;
  border: 2px solid #cbd2e0;
  border-radius: 50%;
  margin-top: 2px;
  position: relative;
  transition: border-color .15s;
}
.rc-radio::after {
  content: "";
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%) scale(0);
  width: 10px; height: 10px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  transition: transform .15s;
}
.radio-card input:checked ~ .rc-radio { border-color: var(--primary); }
.radio-card input:checked ~ .rc-radio::after { transform: translate(-50%, -50%) scale(1); }
.radio-card:has(input:checked) {
  border-color: var(--primary);
  background: var(--primary-soft);
  box-shadow: 0 0 0 3px var(--primary-glow);
}
.rc-body { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.rc-title {
  font-size: 13px; font-weight: 600; color: var(--text);
}
.rc-sub {
  font-size: 11px; color: var(--muted);
}
.radio-card:has(input:checked) .rc-title { color: var(--primary); }
.radio-card.disabled { opacity: .5; cursor: not-allowed; pointer-events: none; }

/* ===== 提示图标 ===== */
.info {
  display: inline-flex; align-items: center; justify-content: center;
  width: 14px; height: 14px; margin-left: 6px;
  border-radius: 50%; background: #e0e6f0; color: #6c7793;
  font-size: 9px; font-weight: 700; font-style: normal;
  font-family: Georgia, serif; cursor: help;
  position: relative; flex-shrink: 0; user-select: none;
  transition: background .15s;
}
.info:hover { background: var(--primary-soft); color: var(--primary); }
.info::after {
  content: attr(data-tip);
  position: absolute; bottom: 100%; left: 50%;
  transform: translateX(-50%) translateY(-8px);
  background: #1e2739; color: #fff;
  padding: 8px 11px; border-radius: 8px;
  font-size: 11px; font-weight: 400; line-height: 1.55;
  white-space: pre-line; width: max-content; max-width: 240px;
  text-align: left; font-family: -apple-system, "Segoe UI", "PingFang SC", sans-serif;
  box-shadow: 0 6px 18px rgba(0, 0, 0, .25);
  opacity: 0; visibility: hidden; transition: opacity .15s;
  pointer-events: none; z-index: 100;
}
.info::before {
  content: ""; position: absolute; bottom: 100%; left: 50%;
  transform: translateX(-50%) translateY(-2px);
  border: 5px solid transparent; border-top-color: #1e2739;
  opacity: 0; visibility: hidden; transition: opacity .15s;
  pointer-events: none; z-index: 100;
}
.info:hover::after, .info:hover::before,
.info.show::after, .info.show::before {
  opacity: 1; visibility: visible;
}
.info.light { background: rgba(255, 255, 255, .22); color: #fff; }
.info.light:hover { background: rgba(255, 255, 255, .4); }

/* ===== 结果 (现代化) ===== */
.result {
  position: relative;
  background: #ffffff;
  color: var(--text);
  border-radius: var(--radius);
  padding: 24px 22px 18px;
  border: 1px solid var(--bd);
  box-shadow: var(--shadow-md);
  overflow: visible;  /* 关键:不裁掉 tooltip */
}
.res-head {
  font-size: 12px; color: var(--muted);
  display: flex; align-items: center; justify-content: center; gap: 6px;
  letter-spacing: 1px;
  text-transform: uppercase;
}
/* 两个并列数值单元格：钢件 / 铝件 */
.res-duo {
  display: grid; grid-template-columns: 1fr 1fr; gap: 12px;
  margin-top: 14px;
}
.res-cell {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  padding: 18px 12px 16px;
  border-radius: var(--rs);
  border: 1px solid var(--bd);
  background: #fbfbfe;
}
.res-cell-steel {
  background: linear-gradient(160deg, #ffffff, #eef0fe);
  border-color: rgba(99, 102, 241, .25);
}
.res-cell-alu {
  background: linear-gradient(160deg, #ffffff, #f6f2fc);
  border-color: rgba(168, 85, 247, .22);
}
.rc-lbl {
  font-size: 13px; font-weight: 600; color: var(--text-soft);
  letter-spacing: .5px;
}
.res-cell-steel .rc-lbl { color: var(--primary); }
.res-cell-alu .rc-lbl { color: #8b5cf6; }
.rc-val {
  display: inline-flex; align-items: baseline; gap: 6px;
  font-size: 38px; font-weight: 700; line-height: 1;
  font-family: "Cambria Math", "Consolas", monospace;
  letter-spacing: -1px;
  color: var(--text);
}
.res-cell-steel .rc-val b {
  background: linear-gradient(135deg, #4f46e5 0%, #6366f1 100%);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}
.res-cell-alu .rc-val b {
  background: linear-gradient(135deg, #a855f7 0%, #d946ef 100%);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}
.rc-val .unit {
  font-size: 13px; font-weight: 500; opacity: .8;
  color: var(--text-soft);
  -webkit-text-fill-color: var(--text-soft);
}
.res-meta {
  display: flex; justify-content: center; flex-wrap: wrap;
  gap: 6px 18px; margin-top: 16px; padding-top: 14px;
  border-top: 1px solid var(--bd-soft);
  font-size: 12px; color: var(--text-soft);
  position: relative;
}
.res-meta span { display: inline-flex; align-items: baseline; gap: 6px; }
.res-meta em {
  font-style: normal; font-family: "Cambria Math", serif;
  font-size: 11px; opacity: .7;
}
.res-meta b {
  color: var(--text); font-weight: 600;
  font-family: "Cambria Math", "Consolas", monospace;
  font-size: 13px;
}

.foot {
  text-align: center; font-size: 11px; color: var(--muted);
  padding: 6px 0 4px;
  letter-spacing: .3px;
}

/* ===== 手机端 ===== */
@media (max-width: 680px) {
  .container { padding: 12px 12px; gap: 12px; }
  .card { padding: 16px; border-radius: 12px; }
  .grid-2 { grid-template-columns: 1fr; }
  .topbar { padding: 10px 14px; }
  .brand h1 { font-size: 15px; }
  .logo { width: 28px; height: 28px; font-size: 16px; }
  .rc-val { font-size: 30px; }
  .res-duo { gap: 8px; }
  .res-cell { padding: 14px 8px 13px; }
  .chip { min-width: 76px; padding: 6px 9px; }
  .chip b { font-size: 13px; }
  .card-head { flex-wrap: wrap; gap: 8px; }
  .info { width: 17px; height: 17px; font-size: 11px; }
  .info::after { max-width: 200px; }
  .res-meta { font-size: 11px; gap: 4px 10px; }
  .res-meta b { font-size: 12px; }
  .seg-radios { grid-template-columns: 1fr; }
}
@media (max-width: 380px) {
  .rc-val { font-size: 27px; }
  .card { padding: 14px; }
  .radio-card { padding: 10px 12px; }
}