:root {
  --bg: #0a0a0f;
  --panel: #0f1117;
  --border: #1e2535;
  --accent: #00f5a0;
  --accent2: #00d9f5;
  --danger: #f5004a;
  --text: #c8d6e5;
  --muted: #4a5568;
  --glow: 0 0 20px rgba(0,245,160,0.3);
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Courier New', Courier, monospace;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem;
  background-image:
    radial-gradient(ellipse at 20% 0%, rgba(0,245,160,0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(0,217,245,0.05) 0%, transparent 50%);
}

header {
  text-align: center;
  margin-bottom: 2.5rem;
}

header h1 {
  font-family: Georgia, 'Times New Roman', serif;
  font-size: clamp(1.8rem, 5vw, 3rem);
  font-weight: 900;
  letter-spacing: 0.1em;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: none;
}

header p {
  color: var(--muted);
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  margin-top: 0.4rem;
  text-transform: uppercase;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  width: 100%;
  max-width: 680px;
  margin-bottom: 1.2rem;
}

.card-title {
  font-family: Georgia, 'Times New Roman', serif;
  font-size: 0.65rem;
  letter-spacing: 0.25em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.card-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

.methods {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.6rem;
}

.method-btn {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.8rem 0.5rem;
  color: var(--muted);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}
.method-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.method-btn.active {
  background: rgba(0,245,160,0.08);
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: var(--glow);
}
.method-name {
  display: block;
  font-size: 0.85rem;
  font-weight: bold;
  margin-bottom: 0.2rem;
  font-family: Georgia, 'Times New Roman', serif;
}

.info-box {
  background: rgba(0,245,160,0.04);
  border-left: 2px solid var(--accent);
  border-radius: 0 6px 6px 0;
  padding: 0.8rem 1rem;
  font-size: 0.78rem;
  color: var(--text);
  line-height: 1.6;
  margin-bottom: 1rem;
}
.info-box .tag {
  color: var(--accent2);
  font-weight: bold;
}

.options-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}
.opt-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  flex: 1;
  min-width: 120px;
}
.opt-group label {
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  color: var(--muted);
  text-transform: uppercase;
}
.opt-group input {
  background: #0a0e16;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.5rem 0.75rem;
  color: var(--accent);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.85rem;
  outline: none;
  transition: border-color 0.2s;
  width: 100%;
}
.opt-group input:focus {
  border-color: var(--accent);
}

textarea {
  width: 100%;
  background: #0a0e16;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  color: var(--text);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.85rem;
  resize: vertical;
  min-height: 90px;
  outline: none;
  transition: border-color 0.2s;
  line-height: 1.6;
}
textarea:focus { border-color: var(--accent); }
textarea::placeholder { color: var(--muted); }

.textarea-label {
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
  display: block;
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin: 1rem 0;
}
.btn {
  flex: 1;
  padding: 0.85rem;
  border-radius: 8px;
  border: none;
  font-family: Georgia, 'Times New Roman', serif;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: all 0.2s;
  text-transform: uppercase;
}
.btn-encrypt {
  background: linear-gradient(135deg, #00f5a0, #00d9f5);
  color: #0a0a0f;
}
.btn-encrypt:hover {
  box-shadow: 0 0 25px rgba(0,245,160,0.5);
  transform: translateY(-1px);
}
.btn-decrypt {
  background: transparent;
  border: 1px solid var(--accent2);
  color: var(--accent2);
}
.btn-decrypt:hover {
  background: rgba(0,217,245,0.08);
  box-shadow: 0 0 20px rgba(0,217,245,0.3);
  transform: translateY(-1px);
}

.output-section { margin-top: 0.5rem; }
.output-box {
  background: #0a0e16;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  min-height: 70px;
  font-size: 0.85rem;
  line-height: 1.7;
  word-break: break-all;
  position: relative;
  color: var(--accent);
  transition: border-color 0.3s;
}
.output-box.has-content { border-color: rgba(0,245,160,0.3); }
.output-box .placeholder { color: var(--muted); }

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: rgba(0,245,160,0.1);
  border: 1px solid rgba(0,245,160,0.3);
  border-radius: 5px;
  color: var(--accent);
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.65rem;
  padding: 0.2rem 0.5rem;
  cursor: pointer;
  transition: all 0.2s;
  letter-spacing: 0.1em;
}
.copy-btn:hover { background: rgba(0,245,160,0.2); }

.viz {
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(0,0,0,0.3);
  border-radius: 8px;
  border: 1px dashed var(--border);
  font-size: 0.75rem;
  line-height: 2;
  display: none;
}
.viz.show { display: block; }
.viz-row { display: flex; flex-wrap: wrap; gap: 0.3rem; margin-bottom: 0.3rem; }
.viz-label { color: var(--muted); font-size: 0.65rem; letter-spacing: 0.15em; text-transform: uppercase; margin-bottom: 0.4rem; }
.char-box {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.2rem 0.4rem;
  min-width: 28px;
  text-align: center;
}
.char-box .orig { color: var(--muted); font-size: 0.6rem; }
.char-box .result { color: var(--accent); font-size: 0.8rem; font-weight: bold; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}

.error { color: var(--danger); font-size: 0.78rem; margin-top: 0.4rem; min-height: 1.2em; }

.disclaimer {
  margin-top: 1.2rem;
  font-size: 0.7rem;
  color: var(--muted);
  text-align: center;
  line-height: 2;
  letter-spacing: 0.05em;
}

.disclaimer-thanks {
  font-family: 'Thank You', cursive;
  font-size: 2rem;
  color: var(--accent);
  letter-spacing: 0.02em;
  display: inline-block;
  margin: 0.2rem 0;
}

::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }