:root {
  color-scheme: light;
  --navy: #082942;
  --blue: #0b5f82;
  --cyan: #33a7b4;
  --orange: #ef7a34;
  --ink: #172735;
  --muted: #647684;
  --line: #d8e4ea;
  --paper: #f3f7f8;
  --white: #fff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 90% 5%, rgba(51, 167, 180, .14), transparent 22rem),
    var(--paper);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

.basic-page {
  width: min(1060px, calc(100% - 28px));
  margin: 0 auto;
  padding: 46px 0 36px;
}

.basic-hero {
  padding: 38px;
  border-radius: 18px;
  color: var(--white);
  background:
    linear-gradient(125deg, rgba(8, 41, 66, .97), rgba(11, 95, 130, .92)),
    linear-gradient(45deg, var(--navy), var(--blue));
  box-shadow: 0 22px 48px rgba(8, 41, 66, .18);
}

.eyebrow {
  display: inline-block;
  margin-bottom: 10px;
  color: #8fe0e7;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .12em;
}

.basic-hero h1 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.18;
}

.basic-hero p {
  max-width: 760px;
  margin: 0;
  color: rgba(255, 255, 255, .82);
  font-size: 16px;
  line-height: 1.8;
}

.basic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin: 22px 0;
}

.calc-card,
.formula-card,
.notice {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--white);
  box-shadow: 0 12px 30px rgba(8, 41, 66, .07);
}

.calc-card {
  position: relative;
  padding: 28px;
  overflow: hidden;
}

.step {
  position: absolute;
  top: 18px;
  right: 22px;
  color: rgba(11, 95, 130, .1);
  font-size: 58px;
  font-weight: 900;
  line-height: 1;
}

.calc-card h2 {
  position: relative;
  margin: 0 0 22px;
  color: var(--navy);
  font-size: 21px;
}

label {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 5px 12px;
  margin-top: 15px;
  color: #344b5d;
  font-size: 14px;
  font-weight: 700;
}

label span {
  color: var(--muted);
  font-weight: 500;
}

input {
  grid-column: 1 / -1;
  width: 100%;
  padding: 12px 13px;
  border: 1px solid #bdd0da;
  border-radius: 8px;
  background: #fbfdfe;
  color: var(--ink);
  font: inherit;
  font-size: 16px;
  outline: 0;
}

input:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(51, 167, 180, .14);
}

.result {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-top: 22px;
  padding: 18px;
  border-radius: 10px;
  background: #e9f5f6;
}

.result > span {
  color: var(--muted);
  font-size: 13px;
}

.result > strong {
  margin-left: auto;
  color: var(--orange);
  font-size: 30px;
}

.result em {
  color: var(--muted);
  font-size: 13px;
  font-style: normal;
}

.result.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.result.split span {
  display: grid;
  gap: 3px;
}

.result.split span + span {
  padding-left: 14px;
  border-left: 1px solid #c9dfe2;
}

.result.split strong {
  color: var(--orange);
  font-size: 26px;
}

.message {
  min-height: 38px;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.55;
}

.formula-card,
.notice {
  margin-top: 20px;
  padding: 22px 26px;
}

.formula-card {
  display: grid;
  gap: 10px;
}

.formula-card strong,
.notice strong {
  color: var(--blue);
  font-size: 16px;
}

.formula-card code {
  display: block;
  width: fit-content;
  padding: 7px 10px;
  border-radius: 6px;
  background: #edf3f6;
  color: var(--navy);
  font-family: Consolas, monospace;
  font-size: 15px;
}

.formula-card span,
.notice p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.notice {
  border-left: 4px solid var(--orange);
}

.notice p { margin-top: 8px; }

@media (max-width: 760px) {
  .basic-page { width: min(100% - 20px, 1060px); padding-top: 20px; }
  .basic-hero { padding: 28px 22px; border-radius: 14px; }
  .basic-grid { grid-template-columns: 1fr; }
  .calc-card { padding: 24px 20px; }
  .result.split { grid-template-columns: 1fr; }
  .result.split span + span { padding: 12px 0 0; border-top: 1px solid #c9dfe2; border-left: 0; }
}