@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;600;700&display=swap');

*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --bg: #eef2f6;
  --bg-rgb: 238, 242, 246;
  --surface: #ffffff;
  --surface-raised: #fbfcfe;
  --surface-muted: #f3f6fa;
  --ink: #172033;
  --muted: #647084;
  --subtle: #94a0b4;
  --line: #d8e0eb;
  --primary: #2357d9;
  --primary-strong: #183fa8;
  --primary-soft: #e8eefc;
  --accent: #047b75;
  --accent-soft: #dff8f4;
  --warning: #b45309;
  --danger: #be3144;
  --danger-soft: #fff0f2;
  --success: #087443;
  --shadow: 0 20px 60px rgba(23, 32, 51, 0.12);
  --shadow-soft: 0 10px 30px rgba(23, 32, 51, 0.08);
  --radius: 8px;
  --nav-h: 68px;
  --font-ui: 'Manrope', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', Consolas, monospace;
  --motion: 180ms ease;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0a1020;
  --bg-rgb: 10, 16, 32;
  --surface: #111a2e;
  --surface-raised: #162139;
  --surface-muted: #0d1628;
  --ink: #eef4ff;
  --muted: #aeb9cb;
  --subtle: #76849a;
  --line: #26344d;
  --primary: #82a4ff;
  --primary-strong: #b2c5ff;
  --primary-soft: #1d2e57;
  --accent: #55d6c7;
  --accent-soft: #123d3c;
  --danger: #ff7d90;
  --danger-soft: #3a1720;
  --success: #73e4aa;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.42);
  --shadow-soft: 0 14px 36px rgba(0, 0, 0, 0.3);
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    linear-gradient(135deg, rgba(35, 87, 217, 0.16), transparent 34rem),
    linear-gradient(225deg, rgba(4, 123, 117, 0.13), transparent 30rem),
    var(--bg);
  color: var(--ink);
  font-family: var(--font-ui);
  font-size: 15px;
  line-height: 1.55;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(100, 112, 132, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(100, 112, 132, 0.1) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: linear-gradient(180deg, #000, transparent 680px);
}

button,
input,
textarea {
  font: inherit;
}

button {
  border: 0;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(35, 87, 217, 0.28);
  outline-offset: 2px;
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  height: var(--nav-h);
  background: rgba(var(--bg-rgb), 0.82);
  border-bottom: 1px solid rgba(148, 160, 180, 0.22);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  transition: box-shadow var(--motion), background var(--motion);
}

.site-nav.scrolled {
  box-shadow: var(--shadow-soft);
}

.nav-inner {
  width: min(100%, 1200px);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.brand-mark,
.section-code {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid color-mix(in srgb, var(--primary) 22%, transparent);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--primary-soft), color-mix(in srgb, var(--accent-soft) 72%, transparent));
  color: var(--primary-strong);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 800;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 6px;
  min-width: 0;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-links::-webkit-scrollbar {
  display: none;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 8px 13px;
  border-radius: var(--radius);
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
  transition: color var(--motion), background var(--motion);
}

.nav-link:hover,
.nav-link.active {
  background: var(--primary-soft);
  color: var(--primary-strong);
}

.theme-toggle,
.btn-secondary {
  min-height: 38px;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
  transition: transform var(--motion), border-color var(--motion), background var(--motion);
}

.theme-toggle {
  margin-left: auto;
}

.theme-toggle:hover,
.btn-secondary:hover {
  border-color: color-mix(in srgb, var(--primary) 45%, var(--line));
  transform: translateY(-1px);
}

.page-shell {
  width: min(100%, 1200px);
  margin: 0 auto;
  padding: 36px 24px 80px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 390px);
  gap: 24px;
  align-items: stretch;
  margin-bottom: 24px;
}

.hero-copy,
.hero-panel,
.history-panel,
.cipher-section {
  border: 1px solid rgba(148, 160, 180, 0.28);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  box-shadow: var(--shadow-soft);
}

.hero-copy {
  padding: clamp(28px, 5vw, 56px);
}

.eyebrow,
.panel-kicker,
.section-kicker,
.form-label,
.result-label,
.matrix-caption {
  margin: 0;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  margin: 10px 0 14px;
  color: var(--ink);
  font-size: clamp(42px, 7vw, 84px);
  line-height: 0.95;
  letter-spacing: 0;
}

.hero p {
  max-width: 680px;
  margin: 0;
  color: var(--muted);
  font-size: clamp(16px, 2.2vw, 20px);
}

.hero-panel {
  display: grid;
  gap: 1px;
  overflow: hidden;
}

.hero-panel > div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 120px;
  padding: 24px;
  background: linear-gradient(135deg, var(--surface-raised), var(--surface));
}

.metric-value {
  color: var(--primary-strong);
  font-family: var(--font-mono);
  font-size: 32px;
  font-weight: 800;
}

.metric-label {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.history-panel {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: start;
  margin-bottom: 24px;
  padding: 22px;
}

.history-panel h2 {
  margin: 4px 0 0;
  font-size: 22px;
}

.history-list {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.history-list.empty {
  display: block;
  padding: 16px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  background: var(--surface-muted);
}

.history-item {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.history-item div {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
  color: var(--ink);
  text-transform: capitalize;
}

.history-item div span,
.history-item p span {
  color: var(--subtle);
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
}

.history-item p {
  display: grid;
  gap: 3px;
  margin: 8px 0 0;
  color: var(--muted);
  overflow-wrap: anywhere;
}

.cipher-section {
  margin-bottom: 24px;
  padding: clamp(18px, 3vw, 28px);
  scroll-margin-top: calc(var(--nav-h) + 20px);
}

.cipher-section.featured {
  border-color: color-mix(in srgb, var(--primary) 28%, var(--line));
}

.section-head {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 22px;
}

.section-head h2 {
  margin: 2px 0;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.1;
}

.section-head p:last-child {
  margin: 0;
  color: var(--muted);
}

.cipher-grid {
  display: grid;
  grid-template-columns: minmax(280px, 400px) minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.cipher-card,
.result-box,
.process-box,
.preview-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-raised);
}

.cipher-card {
  display: grid;
  gap: 16px;
  padding: 18px;
}

.field-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.form-group {
  display: grid;
  gap: 8px;
}

.form-label span {
  color: var(--primary-strong);
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  transition: border-color var(--motion), box-shadow var(--motion), background var(--motion);
}

input {
  min-height: 46px;
  padding: 10px 13px;
}

textarea {
  min-height: 132px;
  padding: 12px 13px;
  resize: vertical;
}

input:focus,
textarea:focus {
  border-color: color-mix(in srgb, var(--primary) 70%, var(--line));
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 17%, transparent);
}

input::placeholder,
textarea::placeholder {
  color: var(--subtle);
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
}

input[type="number"] {
  -moz-appearance: textfield;
}

.segmented {
  display: inline-grid;
  grid-auto-flow: column;
  gap: 4px;
  width: fit-content;
  max-width: 100%;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.segment {
  min-height: 36px;
  padding: 8px 14px;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
  transition: color var(--motion), background var(--motion), box-shadow var(--motion);
}

.segment:hover {
  color: var(--primary-strong);
}

.segment.active {
  background: var(--surface);
  color: var(--primary-strong);
  box-shadow: 0 3px 12px rgba(23, 32, 51, 0.12);
}

.btn-run {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 18px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #ffffff;
  cursor: pointer;
  font-weight: 900;
  box-shadow: 0 14px 30px color-mix(in srgb, var(--primary) 24%, transparent);
  transition: transform var(--motion), filter var(--motion), box-shadow var(--motion);
}

.btn-run:hover {
  filter: brightness(1.05);
  transform: translateY(-1px);
  box-shadow: 0 18px 38px color-mix(in srgb, var(--primary) 30%, transparent);
}

.btn-run:active {
  transform: translateY(0);
}

.btn-run:disabled {
  cursor: wait;
  filter: grayscale(0.25);
  opacity: 0.72;
  transform: none;
}

.help-text,
.note {
  margin: 0;
  padding: 11px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
}

.error-region:empty {
  display: none;
}

.error-msg {
  padding: 12px 13px;
  border: 1px solid color-mix(in srgb, var(--danger) 28%, transparent);
  border-radius: var(--radius);
  background: var(--danger-soft);
  color: var(--danger);
  font-weight: 800;
  animation: rise 180ms ease both;
}

.output-stack {
  display: grid;
  gap: 14px;
}

.result-box {
  position: relative;
  display: none;
  min-height: 116px;
  padding: 18px;
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--accent-soft) 66%, transparent), transparent),
    var(--surface-raised);
}

.result-box.visible {
  display: block;
  animation: rise 220ms ease both;
}

.result-text {
  max-width: calc(100% - 88px);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.6;
  overflow-wrap: anywhere;
}

.btn-copy {
  position: absolute;
  top: 14px;
  right: 14px;
  min-height: 34px;
  padding: 8px 11px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--accent);
  cursor: pointer;
  font-size: 12px;
  font-weight: 900;
  transition: transform var(--motion), background var(--motion);
}

.btn-copy:hover {
  transform: translateY(-1px);
}

.btn-copy.copied {
  color: var(--success);
}

.process-box {
  min-height: 190px;
  padding: 18px;
  overflow: hidden;
}

.empty-state {
  display: grid;
  min-height: 150px;
  place-items: center;
  padding: 18px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--muted);
  text-align: center;
  background: var(--surface-muted);
}

.process-head {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.process-head h3 {
  margin: 3px 0 0;
  font-size: 18px;
}

.process-head code {
  max-width: 300px;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
  color: var(--primary-strong);
  font-family: var(--font-mono);
  font-size: 12px;
  white-space: normal;
}

.process-content {
  display: grid;
  gap: 14px;
  margin-top: 14px;
}

.step-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding-left: 22px;
}

.step-list li {
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
  animation: rise 220ms ease both;
}

.step-list code,
.calc-card code {
  color: var(--primary-strong);
  font-family: var(--font-mono);
  font-weight: 700;
}

.muted-step {
  color: var(--muted);
}

.matrix-inputs {
  display: grid;
  gap: 8px;
  max-width: 310px;
}

.matrix-inputs.matrix-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.matrix-inputs.matrix-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

[hidden] {
  display: none !important;
}

.matrix-showcase {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.matrix-visual-wrap {
  display: grid;
  gap: 8px;
}

.matrix-visual {
  display: grid;
  grid-template-columns: repeat(var(--cols), 48px);
  gap: 7px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
}

.matrix-visual span,
.pf-cell {
  display: grid;
  place-items: center;
  min-height: 42px;
  border: 1px solid color-mix(in srgb, var(--primary) 20%, var(--line));
  border-radius: 6px;
  background: color-mix(in srgb, var(--primary-soft) 72%, var(--surface));
  color: var(--primary-strong);
  font-family: var(--font-mono);
  font-weight: 800;
}

.calc-grid {
  display: grid;
  gap: 10px;
}

.calc-card {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-muted);
  animation: rise 220ms ease both;
}

.calc-card p {
  margin: 5px 0 0;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  overflow-wrap: anywhere;
}

.preview-panel {
  display: grid;
  gap: 10px;
  padding: 13px;
}

.playfair-table {
  display: grid;
  grid-template-columns: repeat(5, minmax(34px, 1fr));
  gap: 6px;
  max-width: 300px;
}

.process-table {
  max-width: 360px;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(7px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

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

  .hero-panel {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .hero-panel > div {
    min-height: 110px;
  }
}

@media (max-width: 720px) {
  :root {
    --nav-h: 64px;
  }

  .nav-inner {
    padding-inline: 14px;
  }

  .nav-brand span:last-child {
    display: none;
  }

  .page-shell {
    padding: 24px 14px 56px;
  }

  .hero-panel,
  .history-list,
  .field-row {
    grid-template-columns: 1fr;
  }

  .history-panel {
    grid-template-columns: 1fr;
  }

  .history-actions {
    width: 100%;
  }

  .btn-secondary,
  .btn-run,
  .segmented {
    width: 100%;
  }

  .segment {
    width: 100%;
  }

  .section-head,
  .process-head {
    flex-direction: column;
  }

  .result-text {
    max-width: 100%;
    padding-top: 38px;
  }
}

@media (max-width: 430px) {
  .nav-link {
    padding-inline: 10px;
  }

  .hero-copy,
  .history-panel,
  .cipher-section {
    padding: 16px;
  }

  .matrix-visual {
    grid-template-columns: repeat(var(--cols), minmax(36px, 1fr));
    width: 100%;
  }
}