:root {
  --bg: #03060f;
  --bg-2: #07111e;
  --panel: rgba(8, 17, 31, 0.88);
  --panel-2: rgba(11, 26, 44, 0.78);
  --ink: #eafff6;
  --muted: #8ca6a0;
  --line: rgba(82, 255, 168, 0.20);
  --line-strong: rgba(82, 255, 168, 0.48);
  --green: #52ffa8;
  --green-2: #16d18f;
  --cyan: #67e8f9;
  --yellow: #faff7a;
  --danger: #fecaca;
  --danger-bg: rgba(127, 29, 29, 0.42);
  --shadow: 0 22px 65px rgba(0, 0, 0, 0.48);
  --radius: 22px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Courier New", Consolas, monospace;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 8%, rgba(82, 255, 168, 0.18), transparent 25%),
    radial-gradient(circle at 85% 10%, rgba(103, 232, 249, 0.12), transparent 28%),
    linear-gradient(135deg, var(--bg), var(--bg-2) 52%, #020617);
  background-attachment: fixed;
  overflow-x: hidden;
}

.matrix-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.36;
  background-image:
    linear-gradient(rgba(82, 255, 168, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(82, 255, 168, 0.055) 1px, transparent 1px),
    repeating-linear-gradient(90deg, transparent 0 58px, rgba(82, 255, 168, 0.04) 58px 60px);
  background-size: 28px 28px, 28px 28px, 120px 100%;
  mask-image: linear-gradient(to bottom, black, transparent 88%);
}

.topbar {
  width: min(1180px, calc(100% - 28px));
  margin: 20px auto 0;
  padding: 16px 18px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(3, 9, 20, 0.76);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
  position: relative;
  z-index: 1;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 20%, var(--yellow), var(--green) 45%, #0e3326 100%);
  color: #00130a;
  font-weight: 950;
  box-shadow: 0 0 30px rgba(82, 255, 168, 0.35);
}

.app-name,
.app-subtitle {
  margin: 0;
}

.app-name {
  font-weight: 950;
  letter-spacing: 0.03em;
  color: #f3fff9;
}

.app-subtitle {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.status-pill {
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--green);
  background: rgba(82, 255, 168, 0.07);
  font-size: 13px;
  font-weight: 800;
}

.main-layout {
  width: min(1180px, calc(100% - 28px));
  margin: 22px auto;
  position: relative;
  z-index: 1;
}

.intro-panel {
  padding: 36px;
  border: 1px solid var(--line);
  border-radius: 30px;
  background:
    linear-gradient(135deg, rgba(8, 17, 31, 0.92), rgba(5, 11, 22, 0.68)),
    linear-gradient(90deg, rgba(82, 255, 168, 0.08), transparent);
  box-shadow: var(--shadow);
  overflow: hidden;
  position: relative;
}

.intro-panel::after {
  content: "01010110 11001001 00110101";
  position: absolute;
  right: -20px;
  bottom: 22px;
  color: rgba(82, 255, 168, 0.10);
  font-size: 42px;
  font-weight: 950;
  transform: rotate(-6deg);
}

.kicker {
  margin: 0 0 12px;
  color: var(--green);
  font-weight: 950;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 12px;
}

.intro-panel h1 {
  max-width: 780px;
  margin: 0 0 14px;
  font-size: clamp(32px, 5vw, 62px);
  line-height: 0.98;
  letter-spacing: -0.06em;
  color: #f6fff9;
}

.intro-panel p:not(.kicker) {
  max-width: 780px;
  margin: 0;
  color: #bfd4cf;
  line-height: 1.75;
}

.flow-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
  position: relative;
  z-index: 1;
}

.flow-strip span {
  padding: 10px 13px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(82, 255, 168, 0.08);
  color: #d9fff0;
  font-weight: 900;
}

.console-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(330px, 0.75fr);
  gap: 18px;
  align-items: start;
  margin-top: 18px;
}

.terminal-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
  overflow: hidden;
}

.terminal-card::before {
  content: "";
  display: block;
  height: 8px;
  background: linear-gradient(90deg, var(--green), var(--cyan), transparent);
  opacity: 0.85;
}

.input-card,
.result-card,
.solution-card {
  padding: 0 24px 24px;
}

.card-title-row {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding-top: 24px;
  margin-bottom: 22px;
}

.card-code {
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  color: var(--green);
  background: rgba(82, 255, 168, 0.08);
  font-weight: 950;
}

.card-title-row h2 {
  margin: 0 0 5px;
  color: #f6fff9;
  letter-spacing: -0.02em;
}

.card-title-row p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.form-group label,
.mode-area > p {
  display: block;
  margin: 0 0 8px;
  color: #d7fff0;
  font-weight: 900;
}

input[type="text"] {
  width: 100%;
  padding: 16px 15px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(0, 8, 14, 0.72);
  color: var(--green);
  font-size: 20px;
  letter-spacing: 5px;
  outline: none;
  transition: 0.2s ease;
}

input[type="text"]:focus {
  border-color: var(--green);
  box-shadow: 0 0 0 4px rgba(82, 255, 168, 0.10), 0 0 22px rgba(82, 255, 168, 0.12);
}

input[type="text"]::placeholder {
  color: rgba(140, 166, 160, 0.55);
}

small {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.5;
}

.mode-area {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 11px;
  margin-top: 22px;
}

.mode-area > p {
  width: 100%;
}

.radio-card {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(0, 8, 14, 0.56);
  color: #d7fff0;
  cursor: pointer;
  font-weight: 900;
  transition: 0.18s ease;
}

.radio-card:hover,
.radio-card:has(input:checked) {
  border-color: var(--green);
  background: rgba(82, 255, 168, 0.10);
  color: #f6fff9;
}

.radio-card input {
  accent-color: var(--green);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 11px;
  margin-top: 24px;
}

.btn {
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 14px 18px;
  font-weight: 950;
  cursor: pointer;
  letter-spacing: 0.06em;
  transition: transform 0.16s ease, box-shadow 0.16s ease, background 0.16s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.primary {
  background: linear-gradient(135deg, var(--green), var(--cyan));
  color: #00130a;
  box-shadow: 0 16px 26px rgba(82, 255, 168, 0.18);
}

.secondary {
  background: rgba(255, 255, 255, 0.06);
  color: #eafff6;
  border-color: var(--line);
}

.ghost {
  background: rgba(250, 255, 122, 0.09);
  color: var(--yellow);
  border-color: rgba(250, 255, 122, 0.24);
}

.error {
  margin-top: 16px;
  padding: 13px 15px;
  border-radius: 12px;
  background: var(--danger-bg);
  color: var(--danger);
  border: 1px solid rgba(248, 113, 113, 0.40);
  font-weight: 850;
}

.hidden {
  display: none !important;
}

.result-panel {
  padding: 18px;
  border: 1px solid var(--line-strong);
  border-radius: 16px;
  background:
    radial-gradient(circle at top left, rgba(82, 255, 168, 0.13), transparent 38%),
    rgba(0, 8, 14, 0.54);
}

.result-label {
  margin: 0 0 14px;
  color: var(--green);
  font-weight: 950;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.bit-output,
.bit-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.output-cell,
.bit-cell {
  min-width: 50px;
  height: 56px;
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(82, 255, 168, 0.36);
  border-radius: 10px;
  background: rgba(0, 8, 14, 0.72);
  box-shadow: inset 0 0 18px rgba(82, 255, 168, 0.07);
}

.bit-cell {
  min-width: 42px;
  height: 48px;
}

.idx {
  width: 100%;
  text-align: center;
  font-size: 10px;
  line-height: 1;
  color: var(--muted);
  padding-bottom: 5px;
}

.bit {
  font-size: 20px;
  line-height: 1;
  font-weight: 950;
  color: var(--green);
  text-shadow: 0 0 14px rgba(82, 255, 168, 0.38);
}

.output-cell .bit {
  font-size: 27px;
}

.solution-card {
  margin-top: 18px;
}

.toggle {
  width: 100%;
  margin-top: 24px;
  padding: 16px 18px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: rgba(82, 255, 168, 0.10);
  color: #f6fff9;
  font-weight: 950;
  cursor: pointer;
}

.solution {
  margin-top: 20px;
}

.solution-intro,
.formula-box,
.final-note {
  padding: 15px 16px;
  border-radius: 13px;
  line-height: 1.72;
}

.solution-intro {
  border: 1px solid var(--line);
  background: rgba(0, 8, 14, 0.50);
  color: #d7fff0;
}

.step-block {
  margin: 16px 0;
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
  background: rgba(0, 8, 14, 0.38);
}

.step-header {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(82, 255, 168, 0.14), rgba(103, 232, 249, 0.08));
}

.step-header h3 {
  margin: 0;
  color: #f6fff9;
  font-size: 18px;
}

.step-header p {
  margin: 7px 0 0;
  color: var(--muted);
  line-height: 1.55;
}

.step-content {
  padding: 16px;
}

.table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 12px 0;
  border-radius: 12px;
}

.calc-table {
  width: 100%;
  min-width: 650px;
  border-collapse: collapse;
  color: #d7fff0;
  background: rgba(0, 8, 14, 0.44);
}

.calc-table th,
.calc-table td {
  border: 1px solid rgba(82, 255, 168, 0.14);
  padding: 10px 12px;
  text-align: center;
  vertical-align: middle;
}

.calc-table th:first-child,
.calc-table td:first-child {
  text-align: left;
  min-width: 210px;
  color: var(--green);
  font-weight: 950;
  background: rgba(82, 255, 168, 0.06);
}

.calc-table thead th {
  background: rgba(82, 255, 168, 0.14);
  color: #f6fff9;
  font-weight: 950;
}

.calc-table tbody tr:nth-child(even) td:not(:first-child) {
  background: rgba(82, 255, 168, 0.04);
}

.bit-char {
  display: inline-flex;
  width: 30px;
  height: 30px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  border: 1px solid rgba(82, 255, 168, 0.28);
  background: rgba(82, 255, 168, 0.07);
  color: var(--green);
  font-weight: 950;
}

.formula-box {
  border-left: 4px solid var(--yellow);
  background: rgba(250, 255, 122, 0.06);
  color: #eafff6;
  margin: 12px 0;
}

.split-grid,
.sbox-detail {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 13px 0;
}

.mini-card {
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px;
  background: rgba(0, 8, 14, 0.44);
}

.mini-card h4 {
  margin: 0 0 8px;
  color: #f6fff9;
}

.mini-card p,
.sbox-detail .mini-card p {
  color: #bfd4cf;
  margin: 6px 0;
  line-height: 1.58;
}

.final-note {
  border: 1px solid var(--line-strong);
  background: rgba(82, 255, 168, 0.08);
  color: var(--green);
  font-weight: 950;
}

.footer {
  width: min(1180px, calc(100% - 28px));
  margin: 0 auto;
  padding: 12px 0 34px;
  color: var(--muted);
  text-align: center;
  position: relative;
  z-index: 1;
}

@media (max-width: 920px) {
  .console-grid {
    grid-template-columns: 1fr;
  }

  .topbar {
    border-radius: 22px;
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 720px) {
  .intro-panel,
  .input-card,
  .result-card,
  .solution-card {
    padding-left: 18px;
    padding-right: 18px;
  }

  .intro-panel {
    padding-top: 26px;
    padding-bottom: 26px;
  }

  .form-grid,
  .split-grid,
  .sbox-detail {
    grid-template-columns: 1fr;
  }

  .actions .btn {
    width: 100%;
  }

  .output-cell,
  .bit-cell {
    min-width: 40px;
  }
}