/* =========================================================
   DES SIMULATOR - Blueprint/Schematic Theme
   ========================================================= */

:root {
  --bg-deep: #0b1622;
  --bg-panel: #0f1f30;
  --bg-panel-light: #142a3f;
  --grid-line: rgba(94, 161, 219, 0.08);
  --accent: #5ea1db;
  --accent-bright: #8ed1ff;
  --accent-warn: #ffb454;
  --accent-ok: #6ee7a8;
  --text-primary: #e7f1fb;
  --text-secondary: #9bb4cc;
  --text-dim: #5f7a93;
  --mono: 'IBM Plex Mono', 'Courier New', monospace;
  --display: 'IBM Plex Sans', 'Segoe UI', sans-serif;
  --border-col: rgba(94, 161, 219, 0.25);
  --radius: 3px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background-color: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--display);
  min-width: 1280px;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 24px 24px;
}

/* ---------- HEADER ---------- */

.site-header {
  border-bottom: 1px solid var(--border-col);
  background: linear-gradient(180deg, rgba(15,31,48,0.9), rgba(15,31,48,0.4));
  padding: 28px 40px 24px;
  position: relative;
  overflow: hidden;
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0; right: 0;
  width: 360px; height: 100%;
  background: repeating-linear-gradient(
    -45deg,
    transparent 0 18px,
    rgba(94,161,219,0.04) 18px 19px
  );
  pointer-events: none;
}

.header-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  position: relative;
  z-index: 1;
}

.title-block .eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--accent);
  text-transform: uppercase;
  margin: 0 0 8px;
}

.title-block h1 {
  font-family: var(--mono);
  font-size: 34px;
  font-weight: 600;
  margin: 0;
  letter-spacing: 0.02em;
  color: var(--text-primary);
}

.title-block h1 .accent {
  color: var(--accent-bright);
}

.title-block .sub {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 10px 0 0;
  max-width: 640px;
  line-height: 1.6;
}

.spec-tag {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-dim);
  text-align: right;
  line-height: 1.8;
  border-left: 1px solid var(--border-col);
  padding-left: 18px;
}

.spec-tag b { color: var(--accent-bright); font-weight: 600; }

/* ---------- LAYOUT ---------- */

.app-shell {
  max-width: 1440px;
  margin: 0 auto;
  padding: 32px 40px 80px;
}

.panel {
  background: var(--bg-panel);
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  margin-bottom: 24px;
  position: relative;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border-col);
}

.panel-header h2 {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin: 0;
  color: var(--accent-bright);
  display: flex;
  align-items: center;
  gap: 10px;
}

.panel-header h2 .step-no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px; height: 22px;
  border: 1px solid var(--accent);
  border-radius: 50%;
  font-size: 11px;
  color: var(--accent);
}

.panel-body {
  padding: 20px;
}

.panel-note {
  font-size: 12px;
  color: var(--text-dim);
  font-family: var(--mono);
}

/* ---------- INPUT FORM ---------- */

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 20px;
  align-items: end;
}

.field label {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.field input {
  width: 100%;
  background: var(--bg-deep);
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  color: var(--accent-bright);
  font-family: var(--mono);
  font-size: 15px;
  padding: 12px 14px;
  letter-spacing: 0.05em;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.field input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(94,161,219,0.12);
}

.field .hint {
  font-size: 11px;
  color: var(--text-dim);
  margin-top: 6px;
  font-family: var(--mono);
}

.mode-toggle {
  display: flex;
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  overflow: hidden;
}

.mode-toggle button {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  background: var(--bg-deep);
  color: var(--text-secondary);
  border: none;
  padding: 12px 18px;
  cursor: pointer;
  transition: all 0.15s;
}

.mode-toggle button.active {
  background: var(--accent);
  color: var(--bg-deep);
  font-weight: 600;
}

.mode-toggle button:hover:not(.active) {
  color: var(--text-primary);
}

.action-row {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
  align-items: center;
}

.btn {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 12px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border-col);
  background: transparent;
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.15s;
}

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

.btn-primary {
  background: var(--accent);
  color: var(--bg-deep);
  border-color: var(--accent);
  font-weight: 600;
}

.btn-primary:hover {
  background: var(--accent-bright);
  border-color: var(--accent-bright);
  color: var(--bg-deep);
}

.btn-ghost {
  color: var(--text-dim);
  border-color: transparent;
}

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

.error-msg {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent-warn);
  padding: 10px 14px;
  border: 1px solid rgba(255,180,84,0.3);
  border-radius: var(--radius);
  background: rgba(255,180,84,0.06);
  margin-top: 16px;
  display: none;
}

.error-msg.show { display: block; }

/* ---------- BIT GRID DISPLAY ---------- */

.bitgrid {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  font-family: var(--mono);
}

.bitgrid .bit {
  width: 22px; height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  background: var(--bg-deep);
  border: 1px solid var(--border-col);
  border-radius: 2px;
  color: var(--text-secondary);
}

.bitgrid .bit.one { color: var(--accent-bright); border-color: var(--accent); }
.bitgrid .bit.changed { color: var(--accent-warn); border-color: var(--accent-warn); background: rgba(255,180,84,0.08); }

.bitgrid.bit-block-8 .bit:nth-child(8n) { margin-right: 8px; }

.byte-label-row {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--text-dim);
  margin-bottom: 4px;
}

/* ---------- VALUE DISPLAY ---------- */

.value-row {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.value-box {
  flex: 1;
  min-width: 240px;
}

.value-box .vlabel {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.value-box .vlabel .pill {
  background: var(--bg-panel-light);
  border: 1px solid var(--border-col);
  border-radius: 10px;
  padding: 2px 8px;
  font-size: 10px;
  color: var(--accent);
}

.value-box .vvalue {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--accent-bright);
  word-break: break-all;
  background: var(--bg-deep);
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  padding: 10px 12px;
}

/* ---------- COLLAPSIBLE ROUND CARDS ---------- */

.round-card {
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  margin-bottom: 10px;
  background: var(--bg-panel-light);
  overflow: hidden;
}

.round-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  cursor: pointer;
  user-select: none;
}

.round-card-header:hover {
  background: rgba(94,161,219,0.06);
}

.round-card-header .rname {
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-bright);
  display: flex;
  align-items: center;
  gap: 12px;
}

.round-card-header .rmeta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-dim);
}

.round-card-header .chevron {
  font-family: var(--mono);
  color: var(--accent);
  transition: transform 0.2s;
  font-size: 13px;
}

.round-card.open .chevron {
  transform: rotate(90deg);
}

.round-card-body {
  display: none;
  padding: 18px;
  border-top: 1px solid var(--border-col);
}

.round-card.open .round-card-body {
  display: block;
}

.flow-step {
  margin-bottom: 18px;
}

.flow-step:last-child { margin-bottom: 0; }

.flow-step h4 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.flow-step h4::before {
  content: "▸";
  color: var(--text-dim);
}

.flow-arrow {
  font-family: var(--mono);
  font-size: 18px;
  color: var(--text-dim);
  text-align: center;
  margin: 6px 0;
}

/* ---------- S-BOX TABLE ---------- */

.sbox-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.sbox-card {
  border: 1px solid var(--border-col);
  border-radius: var(--radius);
  padding: 12px;
  background: var(--bg-deep);
}

.sbox-card .sb-title {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent-bright);
  margin-bottom: 8px;
  font-weight: 600;
}

.sbox-card table {
  width: 100%;
  font-family: var(--mono);
  font-size: 10px;
  border-collapse: collapse;
}

.sbox-card td {
  text-align: center;
  padding: 2px 1px;
  color: var(--text-dim);
  border: 1px solid rgba(94,161,219,0.08);
}

.sbox-card td.highlight {
  background: var(--accent);
  color: var(--bg-deep);
  font-weight: 700;
  border-color: var(--accent-bright);
}

.sbox-card td.row-head, .sbox-card td.col-head {
  color: var(--accent);
  font-weight: 600;
  background: rgba(94,161,219,0.05);
}

.sbox-meta {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 8px;
  line-height: 1.6;
}

.sbox-meta b { color: var(--accent-bright); }

/* ---------- KEY SCHEDULE TABLE ---------- */

.kstable {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 12px;
}

.kstable th, .kstable td {
  border: 1px solid var(--border-col);
  padding: 8px 10px;
  text-align: left;
}

.kstable th {
  background: var(--bg-panel-light);
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 10px;
}

.kstable td {
  color: var(--text-secondary);
}

.kstable td.mono-val {
  color: var(--accent-bright);
  word-break: break-all;
}

.kstable tr:hover td {
  background: rgba(94,161,219,0.04);
}

/* ---------- OUTPUT PANEL ---------- */

.output-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.output-card {
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  padding: 18px;
  background: linear-gradient(135deg, rgba(94,161,219,0.08), transparent);
}

.output-card .olabel {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

.output-card .ohex {
  font-family: var(--mono);
  font-size: 24px;
  color: var(--accent-bright);
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  word-break: break-all;
}

.output-card .obin {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-secondary);
  word-break: break-all;
  line-height: 1.8;
}

/* ---------- ROUND TRIP TEST ---------- */

.roundtrip-result {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 13px;
  padding: 14px 18px;
  border-radius: var(--radius);
  border: 1px solid var(--border-col);
}

.roundtrip-result.pass {
  border-color: var(--accent-ok);
  color: var(--accent-ok);
  background: rgba(110,231,168,0.06);
}

.roundtrip-result.fail {
  border-color: var(--accent-warn);
  color: var(--accent-warn);
  background: rgba(255,180,84,0.06);
}

.status-icon {
  font-size: 18px;
}

/* ---------- FOOTER ---------- */

.site-footer {
  text-align: center;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-dim);
  padding: 30px 0;
  border-top: 1px solid var(--border-col);
  letter-spacing: 0.1em;
}

/* ---------- SCROLLABLE WIDE TABLES ---------- */

.table-scroll {
  overflow-x: auto;
}

/* ---------- EMPTY STATE ---------- */

.empty-state {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 13px;
}

.empty-state .glyph {
  font-size: 32px;
  margin-bottom: 12px;
  opacity: 0.4;
}