:root {
  --bg-primary: #f8fafc;
  --bg-card: #ffffff;
  --bg-subtle: #f1f5f9;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --border-focus: #38bdf8;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --success: #059669;
  --success-light: #ecfdf5;
  --warning: #d97706;
  --warning-light: #fffbeb;
  --danger: #dc2626;
  --danger-light: #fef2f2;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.06), 0 1px 2px -1px rgb(0 0 0 / 0.06);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.08), 0 2px 4px -2px rgb(0 0 0 / 0.06);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.04);
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.55;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* Header */
header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  padding: 0.85rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  box-shadow: var(--shadow-sm);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.container {
  width: 100%;
  max-width: 1060px;
  margin: 0 auto;
  padding: 1.75rem 1rem;
  flex: 1;
}

/* 4-Schritte-Steuerungsleiste */
.stepper {
  display: flex;
  justify-content: space-between;
  margin-bottom: 2rem;
  position: relative;
  gap: 0.5rem;
}

.step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  flex: 1;
  cursor: pointer;
  background: none;
  border: none;
  font-family: inherit;
  color: var(--text-muted);
  padding: 0.5rem 0.25rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
}

.step:hover { color: var(--text-main); }
.step-number {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
  transition: all 0.2s ease;
}

.step.active .step-number {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--primary-light);
}

.step.completed .step-number {
  background: var(--success);
  color: #fff;
  border-color: var(--success);
}

.step-label {
  font-size: 0.8rem;
  font-weight: 500;
}

.step.active .step-label {
  color: var(--primary);
  font-weight: 700;
}

/* Card */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  margin-bottom: 1.5rem;
}

.card h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  color: var(--text-main);
  letter-spacing: -0.015em;
}

.card p.subtitle {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
}

/* Infoboxen & Banner */
.callout {
  padding: 0.85rem 1.15rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
  font-size: 0.835rem;
  line-height: 1.5;
  border: 1px solid transparent;
}
.callout-blue { background: rgba(37, 99, 235, 0.05); border-color: rgba(37, 99, 235, 0.18); border-left: 4px solid var(--primary); }
.callout-green { background: rgba(5, 150, 105, 0.06); border-color: rgba(5, 150, 105, 0.2); border-left: 4px solid var(--success); }
.callout-amber { background: rgba(217, 119, 6, 0.06); border-color: rgba(217, 119, 6, 0.2); border-left: 4px solid var(--warning); }

/* Upload Zone */
.dropzone {
  border: 2px dashed #cbd5e1;
  border-radius: var(--radius-md);
  padding: 2.75rem 1.5rem;
  text-align: center;
  cursor: pointer;
  background: #f8fafc;
  transition: all 0.2s ease;
}

.dropzone:hover, .dropzone.dragover {
  border-color: var(--primary);
  background: var(--primary-light);
  transform: translateY(-1px);
}

.dropzone svg {
  width: 44px;
  height: 44px;
  color: var(--primary);
  margin-bottom: 0.6rem;
}

/* Stat Grid & Yeah-Effekt Cards */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.stat-box {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 1.15rem 1.25rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.stat-box:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.stat-box.highlight-green {
  border-color: rgba(5, 150, 105, 0.35);
  background: linear-gradient(180deg, #ffffff 0%, rgba(5, 150, 105, 0.04) 100%);
}

.stat-box.highlight-blue {
  border-color: rgba(37, 99, 235, 0.3);
  background: linear-gradient(180deg, #ffffff 0%, rgba(37, 99, 235, 0.03) 100%);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 0.35rem;
}

.stat-value {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.stat-sub {
  font-size: 0.725rem;
  color: var(--text-muted);
  margin-top: 0.45rem;
  line-height: 1.35;
}

/* Table */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-card);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.85rem;
}

th, td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-color);
}

th {
  background: var(--bg-subtle);
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.775rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

tr:hover td { background: rgba(248, 250, 252, 0.7); }
tr:last-child td { border-bottom: none; }

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.2rem 0.55rem;
  font-size: 0.725rem;
  font-weight: 600;
  border-radius: 9999px;
}
.badge-success { background: var(--success-light); color: var(--success); border: 1px solid rgba(5, 150, 105, 0.2); }
.badge-warning { background: var(--warning-light); color: var(--warning); border: 1px solid rgba(217, 119, 6, 0.2); }
.badge-danger { background: var(--danger-light); color: var(--danger); border: 1px solid rgba(220, 38, 38, 0.2); }
.badge-info { background: var(--primary-light); color: var(--primary); border: 1px solid rgba(37, 99, 235, 0.2); }

/* Buttons & Inputs */
button, .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.65rem 1.35rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s ease;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}
.btn-primary:hover {
  background: var(--primary-hover);
  box-shadow: 0 4px 6px rgba(37, 99, 235, 0.3);
  transform: translateY(-1px);
}

.btn-outline {
  background: var(--bg-card);
  border-color: var(--border-color);
  color: var(--text-main);
}
.btn-outline:hover {
  background: var(--bg-subtle);
  border-color: #cbd5e1;
}

input, select {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.875rem;
  background: var(--bg-card);
  color: var(--text-main);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--text-main);
}

/* Modals & Overlays */
.mnemonic-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
  background: var(--bg-subtle);
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  font-family: monospace;
  font-size: 0.85rem;
  margin: 1rem 0;
}
.mnemonic-word {
  background: #fff;
  padding: 0.4rem 0.5rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  display: flex;
  gap: 0.4rem;
}
.mnemonic-word span.num { color: var(--text-muted); font-size: 0.75rem; user-select: none; -webkit-user-select: none; }

/* Notice Box */
.notice-box {
  background: var(--bg-subtle);
  border-left: 4px solid var(--primary);
  padding: 0.85rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 1.5rem;
  line-height: 1.45;
}

/* Footer */
footer {
  text-align: center;
  padding: 1.75rem 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  background: var(--bg-card);
  margin-top: auto;
}

@media (max-width: 640px) {
  .stepper { flex-wrap: wrap; }
  .step { min-width: 45%; }
  .card { padding: 1.25rem; }
  .mnemonic-grid { grid-template-columns: repeat(2, 1fr); }
}