:root {
  --bg: #0d0d12;
  --panel: #12131a;
  --panel2: #171922;
  --green: #33ff66;
  --green-dim: #1a9944;
  --amber: #ffb000;
  --red: #ff4455;
  --border: #24303a;
  --text-dim: #6a8877;
  --mono: 'JetBrains Mono', 'Courier New', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  background-image:
    radial-gradient(ellipse at top, #16241c 0%, var(--bg) 60%),
    repeating-linear-gradient(0deg, transparent 0, transparent 2px, rgba(0,0,0,0.15) 3px);
  color: var(--green);
  font-family: var(--mono);
  min-height: 100vh;
  overflow-x: hidden;
}

/* CRT overlays */
.scanlines {
  position: fixed; inset: 0; pointer-events: none; z-index: 9998;
  background: repeating-linear-gradient(0deg, rgba(0,0,0,0) 0, rgba(0,0,0,0) 2px, rgba(0,0,0,0.12) 3px, rgba(0,0,0,0) 4px);
  animation: flick 0.15s infinite;
}
.vignette {
  position: fixed; inset: 0; pointer-events: none; z-index: 9997;
  background: radial-gradient(ellipse at center, transparent 55%, rgba(0,0,0,0.5) 100%);
}
@keyframes flick { 0%,100%{opacity:0.9} 50%{opacity:1} }

.app-root { max-width: 1200px; margin: 0 auto; padding: 20px 16px 48px; position: relative; z-index: 1; }

/* Header */
.hdr { text-align: center; margin-bottom: 22px; animation: fadeDown 0.6s ease both; }
@keyframes fadeDown { from { opacity: 0; transform: translateY(-12px); } to { opacity: 1; transform: none; } }
.hdr-title-row { display: flex; align-items: center; justify-content: center; gap: 14px; }
.hdr-title {
  font-weight: 800; font-size: clamp(1.8rem, 6vw, 3.2rem); letter-spacing: 4px;
  color: var(--green);
  text-shadow: 0 0 8px rgba(51,255,102,0.6), 0 0 24px rgba(51,255,102,0.3);
}
.cursor-blink { animation: blink 1s step-end infinite; font-weight: 400; }
@keyframes blink { 50% { opacity: 0; } }
.hdr-sub { color: var(--text-dim); font-size: 0.8rem; margin-top: 6px; letter-spacing: 1px; }

.power-led {
  width: 12px; height: 12px; border-radius: 50%;
  background: #331515; box-shadow: inset 0 0 3px #000;
}
.power-led.power-on {
  background: var(--red);
  box-shadow: 0 0 10px var(--red), 0 0 20px var(--red);
  animation: pulse 0.8s infinite;
}
@keyframes pulse { 50% { opacity: 0.4; } }

/* Grid */
.grid-main { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 860px) { .grid-main { grid-template-columns: 1fr; } }

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px;
  box-shadow: inset 0 0 30px rgba(51,255,102,0.03), 0 0 0 1px rgba(51,255,102,0.05);
  animation: fadeUp 0.6s ease both;
}
@keyframes fadeUp { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.grid-main .panel:nth-child(2) { animation-delay: 0.1s; }

.panel-head {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 0.75rem; letter-spacing: 2px; color: var(--amber);
  border-bottom: 1px solid var(--border); padding-bottom: 8px; margin-bottom: 10px;
  text-shadow: 0 0 6px rgba(255,176,0,0.4);
}

/* Editor */
.editor-wrap { display: flex; background: #0a0b0f; border: 1px solid var(--border); border-radius: 4px; overflow: hidden; }
.gutter {
  padding: 6px 8px; text-align: right; color: var(--text-dim);
  font-size: 0.8rem; line-height: 20px; background: #0e1014; user-select: none;
  border-right: 1px solid var(--border); min-width: 34px;
}
.gutter-line { height: 20px; }
.gutter-active { color: var(--amber); text-shadow: 0 0 6px var(--amber); font-weight: 700; }
.code-editor {
  flex: 1; background: transparent; color: var(--green); border: none; resize: vertical;
  font-family: var(--mono); font-size: 0.85rem; line-height: 20px; padding: 6px 10px;
  outline: none; white-space: pre; overflow-wrap: normal; overflow-x: auto;
}
.code-editor::selection { background: rgba(51,255,102,0.25); }

.preset-select, .toggle-btn {
  background: var(--panel2); color: var(--green); border: 1px solid var(--border);
  font-family: var(--mono); font-size: 0.72rem; padding: 4px 8px; border-radius: 3px; cursor: pointer;
  letter-spacing: 1px;
}
.toggle-btn:hover, .preset-select:hover { border-color: var(--green-dim); }

/* Toolbar */
.toolbar { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.btn {
  flex: 1; min-width: 76px;
  background: linear-gradient(#1c2029, #12141a);
  color: var(--green); border: 1px solid var(--border);
  font-family: var(--mono); font-weight: 700; font-size: 0.82rem;
  padding: 10px 8px; border-radius: 4px; cursor: pointer; letter-spacing: 1px;
  transition: all 0.12s; box-shadow: 0 2px 0 #05060a;
}
.btn:hover:not(:disabled) { border-color: var(--green-dim); text-shadow: 0 0 6px var(--green); transform: translateY(-1px); }
.btn:active:not(:disabled) { transform: translateY(1px); box-shadow: none; }
.btn:disabled { opacity: 0.35; cursor: not-allowed; }
.btn-run { color: var(--green); border-color: var(--green-dim); }
.btn-run:hover:not(:disabled) { background: linear-gradient(#1a3324, #12241a); }
.btn-reset { color: var(--amber); }

/* Speed */
.speed-row { display: flex; align-items: center; gap: 10px; margin-top: 12px; }
.speed-label { font-size: 0.72rem; color: var(--amber); letter-spacing: 1px; white-space: nowrap; }
.speed-slider { flex: 1; accent-color: var(--amber); height: 4px; }
.speed-val { font-size: 0.72rem; color: var(--text-dim); min-width: 48px; text-align: right; }

/* Status */
.status {
  margin-top: 12px; padding: 8px 10px; border-radius: 4px; font-size: 0.78rem;
  border: 1px solid var(--border); background: #0a0b0f; word-break: break-word; line-height: 1.4;
}
.status-ok { border-color: var(--green-dim); }
.status-err { border-color: var(--red); color: #ff8899; }
.status-tag { font-weight: 700; }
.status-ok .status-tag { color: var(--green); }
.status-err .status-tag { color: var(--red); }
.kbd-hint { margin-top: 8px; font-size: 0.68rem; color: var(--text-dim); letter-spacing: 1px; }

/* Registers */
.reg-group-label { font-size: 0.68rem; color: var(--text-dim); letter-spacing: 2px; margin: 12px 0 6px; }
.reg-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 6px; }
@media (max-width: 420px) { .reg-grid { grid-template-columns: 1fr; } }
.reg-box {
  display: flex; justify-content: space-between; align-items: center;
  background: #0a0b0f; border: 1px solid var(--border); border-radius: 3px;
  padding: 6px 10px; transition: background 0.15s;
}
.reg-label { color: var(--amber); font-size: 0.78rem; font-weight: 700; }
.reg-val { color: var(--green); font-size: 0.82rem; letter-spacing: 0.5px; }
.reg-flash { background: rgba(255,176,0,0.18); border-color: var(--amber); animation: flashReg 0.6s ease; }
@keyframes flashReg { 0% { background: rgba(255,176,0,0.5); } 100% { background: #0a0b0f; } }

/* PC + flags */
.pc-flags { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.pc-box {
  display: flex; align-items: center; gap: 10px;
  background: #0a0b0f; border: 1px solid var(--green-dim); border-radius: 4px;
  padding: 8px 14px; box-shadow: inset 0 0 12px rgba(51,255,102,0.08);
}
.pc-val { font-size: 1.3rem; font-weight: 800; text-shadow: 0 0 8px rgba(51,255,102,0.5); }
.halt-badge {
  background: var(--red); color: #fff; font-size: 0.62rem; font-weight: 700;
  padding: 2px 6px; border-radius: 3px; letter-spacing: 1px;
}
.flags-row { display: flex; gap: 12px; }
.led-wrap { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.led {
  width: 14px; height: 14px; border-radius: 50%;
  background: #1a1015; border: 1px solid #2a2a2a; box-shadow: inset 0 0 4px #000;
}
.led-on {
  background: var(--green);
  box-shadow: 0 0 8px var(--green), 0 0 14px rgba(51,255,102,0.5); border-color: var(--green);
}
.led-label { font-size: 0.68rem; color: var(--text-dim); font-weight: 700; }

/* Memory */
.mem-view {
  background: #0a0b0f; border: 1px solid var(--border); border-radius: 4px;
  padding: 8px; max-height: 210px; overflow-y: auto; font-size: 0.72rem;
}
.mem-row { display: flex; gap: 10px; white-space: nowrap; line-height: 1.6; }
.mem-addr { color: var(--amber); }
.mem-bytes { color: var(--text-dim); }
.mem-byte { margin-right: 4px; }
.mem-nz { color: var(--green); text-shadow: 0 0 4px rgba(51,255,102,0.4); }
.mem-sp { color: var(--bg); background: var(--amber); border-radius: 2px; box-shadow: 0 0 6px var(--amber); }
.mem-ascii { color: var(--green-dim); letter-spacing: 2px; }

/* Reference */
.ref-wrap { margin-top: 18px; }
.ref-toggle {
  background: var(--panel); color: var(--amber); border: 1px solid var(--border);
  font-family: var(--mono); font-size: 0.75rem; letter-spacing: 2px;
  padding: 8px 14px; border-radius: 4px; cursor: pointer; width: 100%; text-align: left;
}
.ref-toggle:hover { border-color: var(--amber); }
.ref-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 6px;
  margin-top: 10px; animation: fadeUp 0.3s ease both;
}
.ref-item {
  background: var(--panel); border: 1px solid var(--border); border-radius: 3px;
  padding: 8px 10px; display: flex; flex-direction: column; gap: 3px;
}
.ref-op { color: var(--green); font-size: 0.76rem; }
.ref-desc { color: var(--text-dim); font-size: 0.7rem; }

/* Footer */
.ftr { text-align: center; margin-top: 28px; color: var(--text-dim); font-size: 0.72rem; letter-spacing: 1px; }
.ftr a { color: var(--green-dim); text-decoration: none; border-bottom: 1px dashed var(--green-dim); }
.ftr a:hover { color: var(--green); border-color: var(--green); }

/* scrollbars */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: #0a0b0f; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--green-dim); }