* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; min-height: 100dvh; display: flex; flex-direction: column; background: #f4f7fc; color: #0b1a33; font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'Microsoft YaHei', sans-serif; }
button, input { font: inherit; }
button { cursor: pointer; }
button:disabled, input:disabled { opacity: .55; cursor: not-allowed; }
[hidden] { display: none !important; }
button:focus-visible, a:focus-visible, .digits-viewport:focus-visible { outline: 3px solid #8ec7ff; outline-offset: 3px; }
.calculator-header { display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr); align-items: center; gap: 16px; flex-shrink: 0; min-height: 66px; padding: 10px 28px; background: #fff; border-bottom: 1px solid #e7edf5; }
.calculator-plan { justify-self: start; display: inline-flex; align-items: center; gap: 7px; padding: 6px 12px; border-radius: 8px; color: #16803d; background: #eaf8ef; font-size: .8rem; font-weight: 500; }
.calculator-plan strong { font-size: .85rem; font-style: italic; font-weight: 800; }
.calculator-title { display: flex; align-items: center; justify-content: center; gap: 10px; margin: 0; font-size: 1.325rem; font-weight: 700; line-height: 1.4; }
.calculator-title-icon { display: grid; place-items: center; width: 36px; height: 36px; color: #006acd; font-size: 1.9rem; font-family: Georgia, serif; }
.calculator-open-link { display: inline-flex; align-items: center; gap: 6px; justify-self: end; color: #69798d; font-size: .9rem; text-decoration: none; white-space: nowrap; }
.calculator-open-link:hover { color: #006acd; }
.calculator-main { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 24px; width: 100%; padding: 32px 24px 16px; }
.calculator-wrapper { display: flex; flex: 1 0 auto; align-items: center; justify-content: center; width: 100%; min-width: 0; }
.pi-card { width: 100%; max-width: 1100px; min-width: 0; padding: 28px; background: #fff; border: 1px solid #e5ebf3; border-radius: 24px; box-shadow: 0 12px 40px rgba(18,61,107,.06); }
.pi-intro { display: flex; align-items: center; flex-wrap: wrap; gap: 18px 32px; padding-bottom: 24px; border-bottom: 1px solid #e7edf5; }
.section-kicker { display: block; margin-bottom: 7px; color: #8895a7; font-size: .75rem; }
.pi-intro h2 { margin: 0 0 9px; color: #315d8d; font-size: 1.45rem; font-weight: 700; }
.pi-intro p { margin: 0; color: #69798d; font-size: .85rem; line-height: 1.8; }
.pi-preview { margin-left: auto; color: #315d8d; font: 1.35rem/1.5 ui-monospace, SFMono-Regular, Consolas, monospace; overflow-wrap: anywhere; }
.pi-preview span { color: #9aa9bb; }
.pi-controls { display: flex; flex-wrap: wrap; align-items: center; gap: 18px 26px; padding: 24px 0; }
.digits-form label { display: block; margin-bottom: 9px; color: #536277; font-size: .85rem; font-weight: 600; }
.input-action { display: flex; gap: 10px; }
input { min-width: 0; max-width: 100%; height: 42px; padding: 9px 12px; border: 1px solid #dce5f0; border-radius: 10px; color: #0b1a33; background: #f8faff; font-size: .875rem; }
input:focus { outline: none; border-color: #006acd; box-shadow: 0 0 0 3px #e7f2ff; }
input[aria-invalid="true"] { border-color: #c44949; }
#digitCount { width: 190px; font-variant-numeric: tabular-nums; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 9px 16px; border: 1px solid #dce5f0; border-radius: 10px; font-size: .85rem; font-weight: 600; line-height: 1.5; white-space: nowrap; }
.button.primary { color: #fff; background: #006acd; border-color: #006acd; }
.button.primary:hover:not(:disabled) { background: #0059b3; }
.button.secondary { color: #536f8b; background: #fff; }
.button.secondary:hover:not(:disabled) { color: #006acd; background: #eef4fe; border-color: #bfd6ec; }
.button.compact { min-height: 34px; padding: 6px 11px; font-size: .75rem; border-radius: 8px; }
.field-hint { margin: 8px 0 0; color: #8895a7; font-size: .72rem; }
.preset-group { display: flex; flex-wrap: wrap; gap: 8px; margin-left: auto; }
.preset { min-height: 36px; padding: 7px 12px; color: #69798d; background: #fff; border: 1px solid #dce5f0; border-radius: 9px; font-size: .8rem; }
.preset[aria-pressed="true"] { color: #006acd; border-color: #b7d5f2; background: #eef4fe; }
.pi-layout { display: grid; grid-template-columns: minmax(0, 1fr) 242px; gap: 22px; align-items: start; }
.digits-panel { min-width: 0; overflow: hidden; border: 1px solid #e0e8f3; border-radius: 18px; }
.digits-heading { display: flex; align-items: center; flex-wrap: wrap; justify-content: space-between; gap: 12px; padding: 18px 18px 14px; }
.digits-heading h3 { margin: 0 0 7px; color: #315d8d; font-size: 1rem; font-weight: 600; }
.digits-heading p { margin: 0; color: #8895a7; font-size: .75rem; }
.digits-heading strong { color: #006acd; font-weight: 600; font-variant-numeric: tabular-nums; }
.export-actions { display: flex; flex-wrap: wrap; gap: 7px; }
.digit-tools { display: flex; flex-wrap: wrap; gap: 12px 18px; padding: 0 18px; }
.inline-form { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; max-width: 100%; color: #69798d; font-size: .75rem; }
.inline-form input { width: 76px; height: 34px; padding: 6px 8px; font-size: .75rem; border-radius: 8px; }
.inline-form .search-input { flex: 1; width: 150px; min-width: 100px; }
#searchForm { flex: 1; min-width: 235px; }
.search-scope { margin: 10px 18px 13px; color: #8895a7; font-size: .7rem; line-height: 1.7; }
.number-display { padding: 0 10px 0 0; border-top: 1px solid #e7edf5; background: #f8faff; }
.integer-part { padding: 12px 0 7px 18px; color: #315d8d; font: 700 1.65rem/1.3 ui-monospace, SFMono-Regular, Consolas, monospace; }
.integer-part span { color: #006acd; }
.digits-viewport { height: 384px; overflow-y: auto; overflow-x: hidden; overscroll-behavior: contain; scrollbar-width: thin; scrollbar-color: #bdcde0 #eef3f9; }
.digits-canvas { position: relative; min-width: 0; }
.pi-row { position: absolute; left: 0; right: 0; display: grid; grid-template-columns: 88px minmax(0, 1fr); align-items: center; height: 32px; padding: 0 10px 0 18px; line-height: 32px; }
.pi-row:nth-child(even) { background: rgba(227,236,248,.35); }
.row-position { color: #97a5b7; font: 10px/32px ui-monospace, SFMono-Regular, Consolas, monospace; user-select: none; }
.row-digits { color: #31516f; font: 16px/32px ui-monospace, SFMono-Regular, Consolas, 'Liberation Mono', monospace; white-space: pre; font-variant-numeric: tabular-nums; }
.row-digits mark { padding: 2px 0; color: #0e6548; background: #bfeeda; border-radius: 2px; }
.digits-footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; padding: 11px 18px; border-top: 1px solid #e7edf5; color: #8895a7; font-size: .68rem; }
.pi-sidebar { display: flex; flex-direction: column; gap: 18px; min-width: 0; }
.info-panel { padding: 20px; border: 1px solid #d2dce9; border-radius: 18px; }
.info-panel h3 { margin: 0 0 14px; color: #315d8d; font-size: .95rem; font-weight: 600; }
.info-panel p { margin: 0; color: #8895a7; font-size: .75rem; line-height: 1.9; }
.circle-diagram { display: block; width: 100%; max-width: 220px; margin: -6px auto 4px; }
.info-panel .formula { margin-bottom: 12px; text-align: center; color: #006acd; font: 1.15rem/1.5 Georgia, serif; }
.approx-list { display: grid; gap: 13px; margin: 0 0 16px; }
.approx-list div { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 5px 10px; }
.approx-list dt { color: #8895a7; font-size: .72rem; }
.approx-list dd { margin: 0; color: #315d8d; font: .85rem/1.5 ui-monospace, SFMono-Regular, Consolas, monospace; }
.info-panel .small-note { padding-top: 12px; border-top: 1px solid #e7edf5; font-size: .7rem; }
.tool-message { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; min-height: 24px; margin-top: 16px; }
#piStatus { margin: 0; color: #69798d; font-size: .78rem; line-height: 1.8; }
#piStatus.is-error { color: #b74646; }
.calculator-tips { flex-shrink: 0; width: 100%; max-width: 1100px; margin-top: auto; padding: 20px 4px 0; border-top: 1px solid #dfe7f1; color: #66758a; font-size: .78rem; line-height: 1.9; text-align: left; }
.calculator-tips h2 { margin: 0 0 12px; color: #315d8d; font-size: .9rem; font-weight: 600; }
.tips-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 22px; }
.tips-grid p { margin: 0; }
.tips-grid strong { display: block; margin-bottom: 4px; color: #536277; font-weight: 600; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
@media (max-width: 900px) { .pi-layout { grid-template-columns: minmax(0, 1fr); } .pi-sidebar { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); } .pi-preview { margin-left: 0; } .preset-group { margin-left: 0; } .tips-grid { grid-template-columns: 1fr; gap: 12px; } }
@media (max-width: 767.98px) { .calculator-header { padding: 8px 16px; gap: 10px; } .calculator-plan { padding: 5px 8px; font-size: .72rem; } .calculator-title { gap: 7px; font-size: 1.175rem; } .calculator-open-link { font-size: .8rem; } .calculator-main { padding: 24px 16px 16px; } .pi-card { padding: 22px; } }
@media (max-width: 575.98px) { .calculator-header { grid-template-columns: minmax(0, 1fr) auto; } .calculator-title { grid-column: 1 / -1; grid-row: 1; } .calculator-plan { grid-column: 1; grid-row: 2; } .calculator-open-link { grid-column: 2; grid-row: 2; } .calculator-main { padding: 20px 12px 16px; } .pi-card { padding: 18px 14px; border-radius: 22px; } .pi-intro { padding-bottom: 18px; } .pi-intro h2 { font-size: 1.2rem; } .pi-preview { font-size: 1.05rem; } .pi-controls { padding: 18px 0; } .digits-form, .input-action { width: 100%; } #digitCount { flex: 1; width: 100%; } .preset { padding: 6px 9px; font-size: .75rem; } .digits-heading, .digit-tools { padding-left: 12px; padding-right: 12px; } .search-scope { margin-left: 12px; margin-right: 12px; } .pi-row { grid-template-columns: 72px minmax(0, 1fr); padding-left: 12px; padding-right: 4px; } .row-digits { font-size: 14px; } .number-display { padding-right: 4px; } .digits-viewport { height: 352px; } .pi-sidebar { grid-template-columns: 1fr; } .circle-diagram { max-width: 180px; } .tool-message { margin-top: 12px; } }