:root { color-scheme: light; --paper: #f6f2e8; --card: #fffdf7; --ink: #173b38; --muted: #4d615b; --line: #93a69a; --positive: #09674e; --negative: #a52f20; --zero: #596565; --accent: #c6dfb7; --field: #ffffff; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { color-scheme: dark; --paper: #142825; --card: #1c3530; --ink: #edf4de; --muted: #bdcdbc; --line: #729087; --positive: #8ce6bd; --negative: #ffb59e; --zero: #bac6c1; --accent: #325342; --field: #102923; } }
:root[data-theme="dark"] { color-scheme: dark; --paper: #142825; --card: #1c3530; --ink: #edf4de; --muted: #bdcdbc; --line: #729087; --positive: #8ce6bd; --negative: #ffb59e; --zero: #bac6c1; --accent: #325342; --field: #102923; }
* { box-sizing: border-box; }
body { margin: 0; color: var(--ink); background: radial-gradient(ellipse at top right, var(--accent), transparent 60%), var(--paper); font: 17px/1.75 "Noto Serif CJK SC", "Songti SC", serif; }
main { max-width: 1180px; margin: auto; padding: 36px 24px; }
header { position: relative; padding: 16px 0 35px; }
.eyebrow, label, button, select, input, textarea, figcaption, table, footer { font-family: "Noto Sans CJK SC", "Microsoft YaHei", sans-serif; }
.eyebrow { font-size: 14px; letter-spacing: .1em; margin-right: 160px; }
h1 { font-size: clamp(34px, 5vw, 64px); line-height: 1.25; margin: 24px 0; letter-spacing: -.04em; }
.intro { max-width: 700px; }
h2 { font-size: 23px; margin-top: 0; }
p { overflow-wrap: anywhere; }
.card { background: var(--card); border: 1px solid var(--line); padding: 26px; margin-bottom: 24px; border-radius: 8px; }
.controls { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
label { display: block; font-size: 15px; min-width: 0; }
output { float: right; font-variant-numeric: tabular-nums; }
input, select, textarea { display: block; width: 100%; min-height: 44px; color: var(--ink); background: var(--field); border: 1px solid var(--line); border-radius: 4px; padding: 8px; font-size: 16px; }
input[type="range"] { padding: 0; accent-color: var(--positive); background: transparent; border: 0; }
button { color: var(--ink); background: var(--accent); border: 1px solid var(--line); min-height: 44px; font-size: 15px; border-radius: 4px; padding: 8px 16px; cursor: pointer; margin-top: 16px; }
#theme { position: absolute; right: 0; top: 0; }
button:hover { filter: brightness(.93); }
:focus-visible { outline: 3px solid var(--positive); outline-offset: 3px; }
:disabled { opacity: .5; }
details { margin-top: 20px; border-top: 1px solid var(--line); padding-top: 15px; }
summary { cursor: pointer; }
textarea { margin: 6px 0 12px; resize: vertical; }
.interval { grid-template-columns: 1fr 1fr 2fr; }
#input-error { color: var(--negative); }
#source-note, #focus-note, #boundary-note, #empty-note { color: var(--muted); }
.formula { padding: 14px; background: var(--accent); font-family: "Noto Serif CJK SC", serif; font-size: 19px; overflow-wrap: anywhere; }
.legend { display: flex; flex-wrap: wrap; gap: 8px 24px; font-size: 15px; }
.positive { color: var(--positive); }
.negative { color: var(--negative); }
.plots { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
figure { margin: 0; min-width: 0; }
figcaption { font-size: 15px; font-weight: bold; }
svg { display: block; width: 100%; height: auto; background: var(--field); margin: 10px 0; border: 1px solid var(--line); }
svg text { font: 15px "Noto Sans CJK SC", sans-serif; fill: var(--ink); }
svg .axis { stroke: var(--line); stroke-width: 1; }
svg .area { fill-opacity: .12; stroke-width: 1.5; }
svg .pos { fill: var(--positive); stroke: var(--positive); }
svg .neg { fill: var(--negative); stroke: var(--negative); stroke-dasharray: 6 4; }
svg .zero { fill: none; stroke: var(--zero); }
svg .focused { fill-opacity: .28; stroke-width: 3.5; }
svg .direction { fill: none; stroke: var(--ink); stroke-width: 1.5; }
.table-wrap { overflow-x: auto; max-height: 410px; border: 1px solid var(--line); }
table { border-collapse: collapse; width: 100%; font-size: 15px; font-variant-numeric: tabular-nums; white-space: nowrap; }
th, td { padding: 8px 12px; text-align: right; border-bottom: 1px solid var(--line); }
thead { background: var(--accent); }
tr.active { background: var(--accent); }
.prediction { border-left: 5px solid var(--positive); }
#prediction { display: flex; gap: 15px; align-items: end; }
#prediction label { flex: 1; }
#prediction button { margin: 0; }
dl { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 18px; }
dd { margin: 0; font-size: 23px; overflow-wrap: anywhere; }
dt { font-size: 15px; color: var(--muted); }
footer { color: var(--muted); font-size: 13px; text-align: center; padding: 20px 0; }
@media (max-width: 700px) { main { padding: 18px 12px; } .card { padding: 18px 14px; } .controls { grid-template-columns: 1fr 1fr; gap: 12px; } .interval { grid-template-columns: 1fr 1fr; } .interval label:last-child { grid-column: 1 / -1; } .plots { grid-template-columns: 1fr; } .eyebrow { margin-right: 0; padding-top: 40px; } #prediction { display: block; } #prediction button { margin-top: 12px; } dl { grid-template-columns: 1fr; gap: 8px; } .formula { font-size: 17px; } }
@media (prefers-reduced-motion: no-preference) { header { animation: reveal .5s ease-out both; } @keyframes reveal { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } } }