:root {
  --bg: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --card-border: rgba(255, 255, 255, 0.08);
  --input-bg: #0f172a;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --accent-hover: linear-gradient(135deg, #4f46e5 0%, #9333ea 100%);
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --radius: 14px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 2.5rem 1rem;
}

.app-container {
  width: 100%;
  max-width: 600px;
}

.app-header {
  margin-bottom: 2rem;
  text-align: center;
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #818cf8;
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 999px;
  margin-bottom: 0.75rem;
}

.app-header h1 {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 0.25rem;
}

/* Card Components */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

.input-card h2 {
  font-size: 1rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

input[type="text"] {
  background: var(--input-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  padding: 0.85rem 1rem;
  border-radius: 10px;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus {
  border-color: #818cf8;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.25rem;
  border-radius: 10px;
  border: none;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
  margin-top: 0.25rem;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.btn-small {
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  border-radius: 8px;
}

.btn-edit {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  border: 1px solid var(--card-border);
}

.btn-edit:hover {
  background: rgba(255, 255, 255, 0.15);
}

.btn-delete {
  background: rgba(239, 68, 68, 0.15);
  color: #fca5a5;
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.btn-delete:hover {
  background: rgba(239, 68, 68, 0.25);
  color: #fff;
}

/* Todo Item List */
.todo-section {
  margin-top: 1.5rem;
}

.render {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.todo-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  animation: fadeIn 0.3s ease;
}

.todo-content {
  flex: 1;
  word-break: break-word;
}

.todo-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.todo-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.todo-actions {
  display: flex;
  gap: 0.5rem;
}

/* Status States */
.state-message {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-secondary);
}

.state-message h3 {
  font-size: 1.1rem;
  font-weight: 500;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}