/* Tyu browser REPL (PLAN-WASM-1 P5): minimal static styling. */

:root {
  --bg: #12141a;
  --panel: #1a1e27;
  --ink: #d7dce6;
  --muted: #7b8494;
  --accent: #5ac8fa;
  --ok: #7dd487;
  --err: #ff7a76;
  --warn: #f2c94c;
  --line: #2a3040;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 14px/1.5 var(--mono);
  height: 100vh;
  display: flex;
  flex-direction: column;
}

#statusbar {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--line);
  background: var(--panel);
}

#brand { font-weight: bold; color: var(--accent); }

#status[data-state="ready"]   { color: var(--ok); }
#status[data-state="booting"] { color: var(--warn); }
#status[data-state="error"]   { color: var(--err); }

#engine-info { margin-left: auto; color: var(--muted); font-size: 12px; }
#backend-mode-label { color: var(--muted); font-size: 12px; }

/* The segmented execution-backend control (W7): the active substrate is
   always visible — no dropdown to open. */
#backend-segments {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow: hidden;
  vertical-align: middle;
}
#backend-segments .segment {
  background: var(--panel);
  color: var(--muted);
  border: none;
  border-radius: 0;
  padding: 0.15rem 0.7rem;
  font: inherit;
  font-size: 12px;
  font-weight: bold;
  cursor: pointer;
}
#backend-segments .segment + .segment { border-left: 1px solid var(--line); }
#backend-segments .segment.active {
  background: #1d3a4d;
  color: var(--accent);
}
#backend-segments .segment:disabled { color: #4a5261; cursor: default; }

.backend-notice { color: var(--warn); border: 1px solid var(--warn); padding: 0.5rem; margin-top: 0.5rem; }

#layout {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 24rem;
  gap: 1rem;
  padding: 1rem;
  min-height: 0;
}

@media (max-width: 900px) {
  #layout {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(16rem, 1fr) minmax(16rem, 1fr);
  }
}

#editor-pane { display: flex; flex-direction: column; min-height: 0; }

#editor {
  flex: 1;
  background: var(--panel);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.75rem;
  font: inherit;
  resize: none;
  min-height: 0;
}

#editor:focus { outline: 1px solid var(--accent); }

#editor-actions { display: flex; gap: 0.5rem; padding: 0.5rem 0; align-items: center; flex-wrap: wrap; }

/* Button hierarchy (W7): run is THE primary action (larger, green), submit
   is the secondary session path (outline), step is a rare debugging nudge. */
button {
  background: var(--accent);
  color: #10222e;
  border: none;
  border-radius: 4px;
  padding: 0.4rem 1.1rem;
  font: inherit;
  font-weight: bold;
  cursor: pointer;
}

button:disabled { background: #33415a; color: var(--muted); cursor: default; }

#run.primary {
  background: var(--ok);
  color: #0a1f0d;
  font-size: 15px;
  padding: 0.5rem 1.5rem;
}
#run.primary:disabled { background: #33415a; }

#submit.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
#submit.secondary:disabled {
  background: transparent;
  border-color: #33415a;
  color: var(--muted);
}

#step.tertiary {
  background: var(--panel);
  color: var(--muted);
  border: 1px solid var(--line);
}
#step.tertiary:disabled { background: var(--panel); }
#step.tertiary:not(:disabled) { color: var(--warn); border-color: var(--warn); }

kbd {
  font: 10px/1 var(--mono);
  color: inherit;
  opacity: 0.75;
  border: 1px solid currentColor;
  border-radius: 3px;
  padding: 0.05rem 0.25rem;
  margin-left: 0.3rem;
  vertical-align: 1px;
}

/* The last action's execution model (W7): program vs session, visible
   BEFORE the status line reports it after the fact. */
.mode-badge {
  font-size: 11px;
  padding: 0.1rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  white-space: nowrap;
}
.mode-badge[data-model="program"] { color: var(--ok); border-color: #1d3324; }
.mode-badge[data-model="session"] { color: var(--accent); border-color: #1d3a4d; }

.mini {
  background: none;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 0.05rem 0.5rem;
  font: inherit;
  font-size: 11px;
  font-weight: normal;
  cursor: pointer;
}
.mini:hover { color: var(--ink); border-color: var(--muted); }
.mini:disabled { background: none; }

.muted { color: var(--muted); font-size: 12px; }

#diag {
  background: #2a1a1c;
  border: 1px solid var(--err);
  border-radius: 4px;
  color: var(--err);
  padding: 0.5rem 0.75rem;
  white-space: pre-wrap;
}

#diag.hidden { display: none; }

#side { display: flex; flex-direction: column; min-height: 0; }

/* The examples sidebar (W3/W7): chapter groups above the tabs, with a
   filter box over the 77-lab corpus. */
#examples-pane {
  flex-shrink: 0;
  margin-bottom: 0.5rem;
}
#examples-pane > summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  list-style: none;
}
#examples-pane > summary::before { content: "▸ "; }
#examples-pane[open] > summary::before { content: "▾ "; }
#example-filter {
  width: 100%;
  margin: 0.35rem 0;
  padding: 0.25rem 0.5rem;
  background: var(--panel);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 4px;
  font: inherit;
  font-size: 12px;
}
#example-filter:focus { outline: 1px solid var(--accent); }

#examples {
  overflow-y: auto;
  max-height: 14rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.25rem;
  margin-bottom: 0.25rem;
  flex-shrink: 0;
}
#examples details > summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 12px;
  padding: 0.2rem 0.4rem;
  list-style: none;
}
#examples details > summary::before { content: "▸ "; }
#examples details[open] > summary::before { content: "▾ "; }
#examples .example {
  display: flex;
  gap: 0.5rem;
  align-items: baseline;
  width: 100%;
  text-align: left;
  background: none;
  color: var(--ink);
  border: none;
  padding: 0.15rem 0.4rem 0.15rem 1.2rem;
  font: inherit;
  font-size: 12px;
  font-weight: normal;
  cursor: pointer;
}
#examples .example:hover { background: #232939; }
#examples .example.target { outline: 1px solid var(--accent); }
#examples .badge {
  font-size: 10px;
  padding: 0 0.3rem;
  border-radius: 3px;
  flex-shrink: 0;
}
#examples .badge.ok { background: #1d3324; color: var(--ok); }
#examples .badge.diag { background: #33261d; color: var(--warn); }
#examples .badge.native-only { background: #2a2033; color: #b48ead; }
#examples .examples-note { color: var(--muted); font-size: 12px; padding: 0.4rem; }

/* The side tabs (W7): console / stack / debug, one panel fills the rest. */
#side-tabs {
  display: flex;
  gap: 0.25rem;
  flex-shrink: 0;
}
#side-tabs .tab {
  background: var(--panel);
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 4px 4px 0 0;
  padding: 0.25rem 0.9rem;
  font: inherit;
  font-size: 12px;
  font-weight: bold;
  cursor: pointer;
}
#side-tabs .tab.active {
  background: #1d3a4d;
  color: var(--accent);
  border-color: #1d3a4d;
}

.tabpanel {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  border: 1px solid var(--line);
  border-radius: 0 4px 4px 4px;
  background: #161922;
  padding: 0.4rem;
}
.tabpanel[hidden] { display: none; }

.panel-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  flex-shrink: 0;
}

#side h2 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 0.2rem 0 0.25rem;
}

#stack {
  list-style: none;
  margin: 0 0 0.25rem;
  padding: 0.5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  flex: 1;
  display: flex;
  flex-direction: column-reverse; /* bottom-first: index 0 renders at the bottom */
  gap: 0.25rem;
  overflow-y: auto;
  min-height: 4rem;
}

#stack li { display: flex; gap: 0.75rem; }

#stack .ty { color: var(--muted); width: 4.5rem; }

/* Empty states (W7): an empty panel says what will appear there. The
   pseudo-content is decorative — textContent stays empty for the tests. */
#stack:empty::before {
  content: "stack is empty — run `1 2 3` to see values";
  color: var(--muted);
  font-size: 12px;
}
#console:empty::before {
  content: "console ready — output appears here";
  color: var(--muted);
  font-size: 12px;
}
#transcript:empty::before {
  content: "transcript — submissions appear here";
  color: var(--muted);
  font-size: 12px;
}

#console {
  flex: 1;
  margin: 0;
  padding: 0.5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  overflow-y: auto;
  white-space: pre-wrap;
  word-break: break-all;
  min-height: 0;
}

#boot-failure {
  background: #2a1a1c;
  border: 1px solid var(--err);
  color: var(--err);
  padding: 1rem;
  margin: 1rem;
  border-radius: 4px;
  white-space: pre-wrap;
}

/* The debug console (W4): frames/backtrace, transcript, ?debug=1 pane. */
#frames, #transcript {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.4rem;
  overflow-y: auto;
  font-size: 12px;
  margin-bottom: 0.4rem;
  min-height: 3rem;
}
#frames { flex: 1; }
#transcript { flex: 1; max-height: none; }
#frames h3, #transcript .tr-head {
  margin: 0 0 0.2rem;
  font-size: 12px;
  color: var(--accent);
}
#frames ol { margin: 0; padding-left: 1.2rem; }
#frames .bt-row { color: var(--ink); }
#frames .trap-row { margin-top: 0.3rem; color: var(--err); }
#frames .trap-row .bt-row { color: var(--warn); }
#frames .overflow-note, #transcript .overflow-note, #stack .overflow-note {
  color: var(--muted);
  font-size: 11px;
}
#transcript .tr-row { margin-bottom: 0.3rem; }
#transcript .tr-src {
  color: var(--muted);
  white-space: pre-wrap;
  word-break: break-all;
}
#debug-pane {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.4rem;
  font-size: 11px;
  color: var(--muted);
  word-break: break-all;
}
#debug-pane.hidden { display: none; }
#debug-pane button { margin-top: 0.3rem; padding: 0.2rem 0.6rem; font-size: 11px; }

/* The IR pane (W6, FR-32): the last-good --emit=ir render, collapsible. */
#ir-pane {
  flex-shrink: 0;
  margin-bottom: 0.4rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.25rem 0.4rem;
  font-size: 12px;
}
#ir-pane > summary {
  cursor: pointer;
  color: var(--muted);
  list-style: none;
}
#ir-pane > summary::before { content: "▸ "; }
#ir-pane[open] > summary::before { content: "▾ "; }
#ir {
  margin: 0.3rem 0 0;
  max-height: 10rem;
  overflow: auto;
  white-space: pre;
  font-size: 11px;
  color: var(--ink);
}