:root {
  --bg-gradient: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
  --card-bg: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --input-bg: #f8fafc;
  --input-border: #e2e8f0;
  --matrix-bg: #f1f5f9;
  --shadow: 0 20px 40px rgba(15, 23, 42, 0.2);
  --accent: #3b82f6;
}

body.dark {
  --bg-gradient: linear-gradient(135deg, #020617 0%, #0f172a 100%);
  --card-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --input-bg: #0f172a;
  --input-border: #334155;
  --matrix-bg: #0f172a;
  --shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
}

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

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  transition: background 0.3s ease;
}

.broad-layout {
  max-width: 960px !important;
  width: 100%;
}

.app {
  background: var(--card-bg);
  border-radius: 24px;
  padding: 32px;
  box-shadow: var(--shadow);
  transition: background 0.3s ease;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

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

header h1 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-main);
}

#themeToggle {
  border: none;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  width: 42px;
  height: 42px;
  border-radius: 12px;
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.main-grid {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  gap: 32px;
}

@media (max-width: 768px) {
  .main-grid {
    grid-template-columns: 1fr;
  }
}

.input-wrapper {
  margin-bottom: 20px;
}

.converter label {
  display: block;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.75px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

textarea, select {
  width: 100%;
  padding: 14px;
  border-radius: 12px;
  border: 1px solid var(--input-border);
  background: var(--input-bg);
  color: var(--text-main);
  font-size: 15px;
  outline: none;
  font-family: inherit;
  resize: none;
}

.validation-badge {
  font-size: 11px;
  margin-top: 6px;
  font-weight: 600;
  color: #10b981;
}

.validation-badge.invalid {
  color: #ef4444;
}

.dashboard-panel {
  background: var(--matrix-bg);
  border-radius: 20px;
  padding: 24px;
  border: 1px solid var(--input-border);
}

.dashboard-panel h3 {
  font-size: 14px;
  color: var(--text-main);
  margin-bottom: 18px;
}

.matrix-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

@media (max-width: 480px) {
  .matrix-grid {
    grid-template-columns: 1fr;
  }
}

.matrix-card {
  background: var(--card-bg);
  border: 1px solid var(--input-border);
  padding: 16px;
  border-radius: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.matrix-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.05);
}

.matrix-label {
  display: block;
  font-size: 10px;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 6px;
}

.matrix-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
  word-break: break-all;
  max-height: 60px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.history {
  margin-top: 24px;
  border-top: 1px solid var(--input-border);
  padding-top: 20px;
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.history h3 {
  font-size: 13px;
  color: var(--text-main);
}

.text-action-btn {
  background: none;
  border: none;
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

#historyList {
  list-style: none;
  max-height: 120px;
  overflow-y: auto;
}

#historyList li {
  padding: 8px 0;
  border-bottom: 1px solid var(--input-border);
  font-size: 12px;
  color: var(--text-muted);
  word-break: break-all;
}

.empty-state {
  text-align: center;
  font-style: italic;
  padding: 16px 0;
}

.tap-hint {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 18px;
  text-align: center;
}

footer {
  margin-top: 28px;
  text-align: center;
  font-size: 11px;
  color: var(--text-muted);
}