:root { font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: #182235; background: #f3f6f9; font-size: 16px; line-height: 1.5; }
* { box-sizing: border-box; }
body { margin: 0; }
button, input, select { font: inherit; }
a { color: #ab1f28; }
.shell { min-height: 100vh; display: flex; flex-direction: column; }
.topbar { min-height: 76px; background: #111b2d; color: white; padding: 0 max(24px, calc((100vw - 1180px) / 2)); display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.brand { display: flex; align-items: center; gap: 12px; font-size: 1.1rem; font-weight: 700; letter-spacing: -.025em; }
.brand-mark { width: 34px; height: 34px; border-radius: 9px; background: #bc2029; display: grid; place-items: center; font-weight: 800; font-size: 1.1rem; }
.preview-tag { color: #d7e1ef; border: 1px solid #46556c; padding: 5px 10px; border-radius: 5px; font-size: .85rem; white-space: nowrap; }
.workspace { flex: 1; width: min(1180px, calc(100% - 48px)); margin: 0 auto; display: grid; grid-template-columns: minmax(0, 1fr) 310px; gap: 24px; align-content: start; padding: 56px 0 64px; }
.intro { grid-column: 1 / -1; margin-bottom: 12px; }
.eyebrow { color: #a52029; font-weight: 800; letter-spacing: .14em; font-size: .79rem; margin: 0 0 10px; }
h1 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -.055em; line-height: 1.1; margin: 0 0 12px; }
.intro > p:last-child { color: #526075; font-size: 1.05rem; margin: 0; max-width: 670px; }
.tool, .boundary { background: white; border: 1px solid #dce3eb; box-shadow: 0 8px 36px rgba(23, 40, 66, .045); border-radius: 13px; }
.tool { padding: 32px; }
.form-head { display: flex; align-items: start; justify-content: space-between; gap: 18px; margin-bottom: 22px; }
h2 { font-size: 1.2rem; margin: 0 0 5px; letter-spacing: -.025em; }
.form-head p, .boundary p { color: #5d6b7d; margin: 0; }
.read-only { color: #6c7789; border: 1px solid #d8e0e8; background: #f6f8fa; border-radius: 4px; padding: 5px 8px; font-size: .73rem; font-weight: 800; letter-spacing: .08em; white-space: nowrap; }
label { display: block; font-weight: 700; font-size: .9rem; margin: 18px 0 8px; }
input, select { width: 100%; min-height: 49px; border-radius: 6px; border: 1px solid #bac6d3; background: white; color: #172133; padding: 10px 13px; outline: none; }
input { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9rem; }
input:focus, select:focus, button:focus-visible, a:focus-visible { outline: 3px solid #f1b3b6; outline-offset: 2px; }
button { border: 0; border-radius: 6px; background: #bc2029; color: white; font-weight: 700; padding: 13px 20px; margin-top: 20px; cursor: pointer; }
button:hover { background: #9e1a23; }
.message { margin: 12px 0 0; color: #a41a22; min-height: 1.5em; font-size: .9rem; }
.result { margin-top: 24px; border-top: 1px solid #e1e7ed; padding-top: 22px; }
.result-title { display: flex; align-items: center; gap: 8px; }
h3 { font-size: 1rem; margin: 0; }
.valid-dot { width: 9px; height: 9px; border-radius: 50%; background: #208354; }
dl { margin: 16px 0; }
dl div { display: grid; grid-template-columns: 110px minmax(0, 1fr); gap: 12px; padding: 10px 0; border-top: 1px solid #edf1f5; }
dt { color: #627185; font-size: .86rem; }
dd { margin: 0; overflow-wrap: anywhere; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .85rem; }
.result a { font-weight: 700; text-decoration: none; }
.result a:hover, footer a:hover { text-decoration: underline; }
.boundary { padding: 28px; align-self: start; }
.boundary p { font-size: .94rem; }
.boundary-rule { border-top: 1px solid #e5eaf0; margin: 24px 0; }
footer { border-top: 1px solid #dce3eb; padding: 20px max(24px, calc((100vw - 1180px) / 2)); color: #637184; font-size: .87rem; display: flex; justify-content: space-between; gap: 12px; }
footer a { text-decoration: none; font-weight: 700; white-space: nowrap; }
@media (max-width: 850px) { .workspace { grid-template-columns: 1fr; padding-top: 35px; } .intro { grid-column: 1; } .boundary { display: grid; grid-template-columns: 1fr 1fr; column-gap: 22px; } .boundary-rule { display: none; } }
@media (max-width: 580px) { .topbar { padding: 16px 20px; align-items: start; flex-direction: column; } .workspace { width: min(100% - 32px, 540px); gap: 17px; } .tool, .boundary { padding: 22px; } .form-head { display: block; } .read-only { display: inline-block; margin-top: 14px; } .boundary { display: block; } .boundary-rule { display: block; } dl div { display: block; } dd { margin-top: 4px; } footer { padding: 18px 20px; display: block; } footer a { display: block; margin-top: 7px; } }