:root {
  color-scheme: light;
  --bg-primary: #f6f8fb;
  --bg-secondary: #ffffff;
  --bg-tertiary: #eef2f6;
  --card-bg: #ffffff;
  --card-hover: #f8fafc;
  --text-primary: #111827;
  --text-secondary: #5f6b7a;
  --text-muted: #657182;
  --accent: #1597d4;
  --accent-hover: #0e7fb5;
  --accent-soft: rgba(21, 151, 212, .10);
  --link: #0876a9;
  --button-bg: #087fb6;
  --button-hover: #086b99;
  --button-text: #ffffff;
  --border: #dce3ea;
  --border-strong: #c9d2dc;
  --success: #177a50;
  --warning: #8b6214;
  --danger: #bd3535;
  --shadow: 0 8px 24px rgba(15, 23, 42, .08);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --space-xs: .25rem;
  --space-sm: .5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --font-sans: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-primary: #0b1118;
  --bg-secondary: #101821;
  --bg-tertiary: #151f2b;
  --card-bg: #111b25;
  --card-hover: #162330;
  --text-primary: #eef4f8;
  --text-secondary: #aebbc8;
  --text-muted: #93a2b2;
  --accent: #22a7e8;
  --accent-hover: #42b8ed;
  --accent-soft: rgba(34, 167, 232, .12);
  --link: #42b8ed;
  --button-bg: #22a7e8;
  --button-hover: #42b8ed;
  --button-text: #0b1118;
  --border: #253443;
  --border-strong: #334659;
  --success: #3ccf91;
  --warning: #e7ad3c;
  --danger: #ef6666;
  --shadow: 0 8px 28px rgba(0, 0, 0, .28);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --bg-primary: #0b1118; --bg-secondary: #101821; --bg-tertiary: #151f2b;
    --card-bg: #111b25; --card-hover: #162330;
    --text-primary: #eef4f8; --text-secondary: #aebbc8; --text-muted: #93a2b2;
    --accent: #22a7e8; --accent-hover: #42b8ed; --accent-soft: rgba(34, 167, 232, .12);
    --link: #42b8ed; --button-bg: #22a7e8; --button-hover: #42b8ed; --button-text: #0b1118;
    --border: #253443; --border-strong: #334659;
    --success: #3ccf91; --warning: #e7ad3c; --danger: #ef6666;
    --shadow: 0 8px 28px rgba(0, 0, 0, .28);
  }
}
* { box-sizing: border-box; }
html { scroll-padding-top: var(--space-xl); }
body { margin: 0; background: var(--bg-primary); color: var(--text-primary); font-family: var(--font-sans); line-height: 1.6; }
a { color: var(--link); text-underline-offset: 4px; }
a:hover { color: var(--link); text-decoration-thickness: 2px; }
.container { width: min(1160px, calc(100% - var(--space-2xl))); margin-inline: auto; }
.site-header { min-height: 88px; display: flex; align-items: center; gap: var(--space-lg); flex-wrap: wrap; padding-block: var(--space-lg); border-bottom: 1px solid var(--border); }
.brand { color: var(--text-primary); font-size: 1.5rem; font-weight: 800; letter-spacing: -.04em; text-decoration: none; }
.brand span { color: var(--link); }
nav { display: flex; gap: var(--space-lg); margin-left: auto; }
nav a { color: var(--text-secondary); text-decoration: none; font-size: .875rem; }
nav a[aria-current] { color: var(--link); font-weight: 650; }
.card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius-md); padding: var(--space-xl); min-width: 0; transition: border-color .15s ease, background-color .15s ease; }
.card:hover { border-color: var(--border-strong); }
.hero { padding: clamp(var(--space-lg), 4vw, var(--space-2xl)); margin-block: var(--space-xl); border-left: 3px solid var(--accent); border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.hero-top, .actions { display: flex; align-items: center; gap: var(--space-md); flex-wrap: wrap; }
.hero-top { justify-content: space-between; }
.eyebrow { color: var(--link); font-size: .75rem; font-weight: 700; letter-spacing: .10em; margin: 0 0 var(--space-sm); }
h1 { font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 600; letter-spacing: -.03em; margin: var(--space-lg) 0 var(--space-sm); }
.ip-address { font-family: var(--font-mono); font-size: clamp(2.375rem, 5vw, 3.5rem); font-weight: 700; letter-spacing: -.045em; line-height: 1.3; overflow-wrap: anywhere; margin: var(--space-sm) 0 var(--space-lg); }
.badge { display: inline-flex; padding: var(--space-xs) var(--space-sm); border: 1px solid var(--border); background: var(--bg-tertiary); color: var(--text-secondary); border-radius: var(--radius-sm); font-size: .75rem; font-weight: 600; }
.ip-badge { background: var(--accent-soft); color: var(--link); }
.button { background: var(--button-bg); color: var(--button-text); border: 1px solid transparent; border-radius: var(--radius-sm); padding: var(--space-sm) var(--space-md); min-height: 44px; font: inherit; font-size: .875rem; font-weight: 650; cursor: pointer; transition: background-color .15s ease, border-color .15s ease; }
.button:hover { background: var(--button-hover); }
.button.secondary { color: var(--text-primary); background: transparent; border-color: var(--border); }
.button.secondary:hover { background: var(--bg-tertiary); border-color: var(--border-strong); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
[hidden] { display: none !important; }
.muted, .note, .privacy-note { color: var(--text-secondary); }
.note { font-size: .8125rem; margin-top: var(--space-md); margin-bottom: 0; }
.notice { color: var(--warning); font-size: .875rem; }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-lg); }
h2 { margin: 0 0 var(--space-lg); font-size: 1.5rem; letter-spacing: -.025em; line-height: 1.3; }
dl { margin: 0; }
.detail-row { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.35fr); align-items: baseline; gap: var(--space-md); padding: var(--space-md) 0; border-bottom: 1px solid var(--border); }
dt { color: var(--text-muted); font-size: .8125rem; font-weight: 500; }
dd { margin: 0; overflow-wrap: anywhere; text-align: right; font-size: 1rem; font-weight: 500; }
#user-agent, .request-card dd { font-size: .875rem; }
.status-badge { display: inline-block; border: 1px solid var(--border); border-radius: var(--radius-sm); padding: var(--space-xs) var(--space-sm); font-size: .8125rem; font-weight: 600; }
.status-ok { color: var(--success); }
.status-warning { color: var(--warning); }
.status-error { color: var(--danger); }
.tools-section { margin-block: var(--space-2xl) var(--space-lg); }
.section-heading { display: flex; justify-content: space-between; align-items: center; gap: var(--space-lg); }
.tools-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-md); }
.tool-card { border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--bg-secondary); padding: var(--space-lg); transition: border-color .15s ease, background-color .15s ease; }
.tool-card:hover { border-color: var(--accent); background: var(--card-hover); }
.tool-icon { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; margin-bottom: var(--space-md); background: var(--accent-soft); color: var(--link); border-radius: var(--radius-sm); }
.tool-icon svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
h3 { font-size: 1.0625rem; margin: 0 0 var(--space-sm); font-weight: 650; }
.tool-description { font-size: .875rem; color: var(--text-secondary); margin: 0 0 var(--space-md); }
.privacy-note { font-size: .8125rem; max-width: 800px; margin-block: var(--space-xl); }
.site-footer { margin-top: var(--space-2xl); border-top: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; gap: var(--space-lg); padding-block: var(--space-lg); font-size: .875rem; color: var(--text-muted); }
.site-footer .brand { font-size: 1.125rem; }
.site-footer a { text-decoration: none; font-weight: 600; }
.site-footer a:hover { text-decoration: underline; }
@media (max-width: 900px) {
  .tools-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 700px) {
  .container { width: calc(100% - var(--space-xl)); }
  .site-header { gap: var(--space-md); }
  nav { order: 3; width: 100%; margin: 0; }
  #theme-toggle { margin-left: auto; }
  .card-grid, .tools-grid { grid-template-columns: 1fr; }
  .card { padding: var(--space-lg); }
  .section-heading, .site-footer { align-items: flex-start; flex-direction: column; gap: var(--space-sm); }
  .detail-row { grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr); gap: var(--space-sm); }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; }
}