/* ============================================================
   ENGINEERING LAB — DESIGN SYSTEM
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500;600&display=swap');

:root {
  /* Color */
  --bg: #07110F;
  --bg-2: #0B1714;
  --surface: #101F1B;
  --border: #1C332C;
  --text: #F4F7F5;
  --text-2: #91A69E;
  --accent: #2ECC87;
  --accent-dim: #1C7A50;
  --warning: #F2B84B;
  --error: #EF6461;
  --info: #62A8FF;

  /* Type */
  --font-body: 'IBM Plex Sans', -apple-system, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, monospace;

  --fs-00: clamp(0.75rem, 0.72rem + 0.15vw, 0.8125rem);
  --fs-0: clamp(0.875rem, 0.85rem + 0.15vw, 0.9375rem);
  --fs-1: clamp(1rem, 0.96rem + 0.2vw, 1.0625rem);
  --fs-2: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
  --fs-3: clamp(1.6rem, 1.4rem + 1vw, 2.1rem);
  --fs-4: clamp(2rem, 1.7rem + 1.5vw, 2.8rem);

  /* Layout */
  --rail-w: 240px;
  --radius: 3px;
  --gap: 1.25rem;
  --transition: 140ms ease;
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

* { box-sizing: border-box; }

html { color-scheme: dark; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-1);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

code, pre, .mono, .metric, .tag, .status-pill, kbd {
  font-family: var(--font-mono);
}

::selection { background: var(--accent-dim); color: var(--text); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

h1, h2, h3, h4 {
  margin: 0 0 0.5em 0;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

h1 { font-size: var(--fs-4); }
h2 { font-size: var(--fs-3); }
h3 { font-size: var(--fs-2); }

p { margin: 0 0 1em 0; color: var(--text-2); max-width: 62ch; }

/* ---------- App shell: left rail + content ---------- */

.shell {
  display: grid;
  grid-template-columns: var(--rail-w) 1fr;
  min-height: 100vh;
}

.rail {
  border-right: 1px solid var(--border);
  background: var(--bg-2);
  padding: 1.5rem 1.25rem;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.rail-brand {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.rail-brand .mark {
  width: 30px; height: 30px;
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  margin-bottom: 0.6rem;
}

.rail-brand .name {
  font-size: var(--fs-0);
  font-weight: 600;
}

.rail-brand .role {
  font-size: var(--fs-00);
  color: var(--text-2);
}

.rail nav {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.rail nav a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.5rem 0.6rem;
  border-radius: var(--radius);
  color: var(--text-2);
  font-size: var(--fs-0);
  border-left: 2px solid transparent;
  transition: color var(--transition), background var(--transition), border-color var(--transition);
}

.rail nav a:hover { color: var(--text); background: var(--surface); }

.rail nav a.active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--surface);
}

.rail nav a .dot {
  width: 5px; height: 5px;
  border-radius: 50%;
  background: currentColor;
  flex-shrink: 0;
}

.rail-footer {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: var(--fs-00);
  color: var(--text-2);
}

.rail-footer a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-2);
}

.rail-footer a:hover { color: var(--accent); }

.rail-toggle {
  display: none;
}

main {
  min-width: 0;
  padding: 2.5rem clamp(1.25rem, 4vw, 3.5rem) 4rem;
}

.page-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.page-header .eyebrow {
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: var(--fs-00);
}

.page-header p { max-width: 60ch; }

/* ---------- Utility ---------- */

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius);
  font-size: var(--fs-00);
  border: 1px solid var(--border);
  background: var(--surface);
}

.status-pill::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.status-pill.active, .status-pill.operational { color: var(--accent); }
.status-pill.demo { color: var(--info); }
.status-pill.experimental { color: var(--warning); }
.status-pill.archived, .status-pill.degraded { color: var(--text-2); }
.status-pill.error, .status-pill.down { color: var(--error); }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: var(--fs-0);
  cursor: pointer;
  font-family: var(--font-body);
  transition: border-color var(--transition), color var(--transition);
}

.btn:hover { border-color: var(--accent); color: var(--accent); }

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
  font-weight: 500;
}

.btn.primary:hover { background: #34d894; color: var(--bg); }

.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.field label {
  font-size: var(--fs-00);
  color: var(--text-2);
}

.field input, .field select, .field textarea {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  padding: 0.55rem 0.7rem;
  font-family: var(--font-body);
  font-size: var(--fs-0);
}

.field textarea { font-family: var(--font-mono); resize: vertical; }

.field input:focus, .field select:focus, .field textarea:focus {
  border-color: var(--accent);
}

.callout {
  border: 1px solid var(--border);
  border-left: 3px solid var(--info);
  background: var(--surface);
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  font-size: var(--fs-00);
  color: var(--text-2);
}

.callout.warning { border-left-color: var(--warning); }
.callout.error { border-left-color: var(--error); }

.empty-state {
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  color: var(--text-2);
  font-size: var(--fs-0);
}

/* ---------- Mobile ---------- */

@media (max-width: 880px) {
  .shell { grid-template-columns: 1fr; }

  .rail {
    position: fixed;
    inset: 0 30% 0 0;
    z-index: 50;
    transform: translateX(-100%);
    transition: transform var(--transition);
    box-shadow: 2px 0 24px rgba(0,0,0,0.5);
  }

  .rail.open { transform: translateX(0); }

  .rail-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    position: sticky;
    top: 0;
    z-index: 40;
    background: var(--bg-2);
    border-bottom: 1px solid var(--border);
    padding: 1rem clamp(1.25rem, 4vw, 3.5rem);
    color: var(--text);
    font-family: var(--font-mono);
    font-size: var(--fs-00);
  }

  .rail-scrim {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 45;
  }

  .rail-scrim.open { display: block; }

  main { padding: 1.5rem 1.25rem 3rem; }
}