/* -------------------------------------------------------------------
   Kalumasol – Professionelles Kalender-Design
   ------------------------------------------------------------------- */

/* Farbvariablen */
:root {
  --primary:     #1E88E5;  /* kräftiges Blau für Header & Buttons */
  --secondary:   #263238;  /* dunkles Anthrazit für Texte & Icons */
  --background:  #FFFFFF;  /* reines Weiß */
  --card-bg:     #F5F7FA;  /* sehr helles Grau für Karten */
  --text:        #263238;  /* Haupttextfarbe */
  --muted:       #607D8B;  /* für Untertexte und Linien */
}

/* Basis-Resets */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Grund-Layout */
body {
  font-family: system-ui, sans-serif;
  background: var(--background);
  color: var(--text);
  line-height: 1.6;
}

/* Zentrierter Container */
.container {
  max-width: 768px;
  margin: 0 auto;
  padding: 1rem;
}

/* -------------------------------------------------------------------
   Header
   ------------------------------------------------------------------- */
.header {
  background: var(--primary);
  color: #fff;
  padding: 2.5rem 0;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.header .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.header h1 {
  font-size: 2.5rem;
  font-weight: 600;
}

.header p {
  font-size: 1.125rem;
  margin-top: 0.25rem;
  color: rgba(255,255,255,0.85);
}

.header nav {
  margin-top: 1rem;
}

.header nav a {
  color: #fff;
  margin: 0 0.75rem;
  text-decoration: none;
  font-weight: 500;
}

.header nav a:hover {
  opacity: 0.85;
}

/* -------------------------------------------------------------------
   Überschriften & Abschnitte
   ------------------------------------------------------------------- */
h2 {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
  color: var(--secondary);
}

section {
  margin: 2rem 0;
}

/* -------------------------------------------------------------------
   Buttons & Formulare
   ------------------------------------------------------------------- */
button {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 0.625rem 1.25rem;
  font-size: 1rem;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

button:hover {
  background: #1565C0;
  transform: translateY(-1px);
}

form,
.converter-form {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  align-items: center;
}

input[type="date"] {
  border: 1px solid #ccc;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  font-size: 1rem;
  color: var(--secondary);
}

/* -------------------------------------------------------------------
   Listen & Links
   ------------------------------------------------------------------- */
ul {
  list-style: none;
  padding-left: 0;
}

ul li + li {
  margin-top: 0.5rem;
}

ul a {
  color: var(--primary);
  text-decoration: none;
}

ul a:hover {
  text-decoration: underline;
}

/* -------------------------------------------------------------------
   Footer
   ------------------------------------------------------------------- */
.footer {
  background: var(--secondary);
  color: #fff;
  text-align: center;
  padding: 1rem 0;
  font-size: 0.9rem;
  margin-top: 2rem;
}

/* -------------------------------------------------------------------
   Feature-Cards
   ------------------------------------------------------------------- */
.feature-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.card {
  background: var(--card-bg);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  border-top: 3px solid var(--primary);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.card h3 {
  margin-bottom: 0.6rem;
  font-size: 1.25rem;
  color: var(--secondary);
}

.card p {
  font-size: 0.95rem;
  line-height: 1.4;
  color: var(--muted);
}

/* -------------------------------------------------------------------
   Converter-Card
   ------------------------------------------------------------------- */
.converter-card {
  border-top: 3px solid var(--secondary);
  background: var(--card-bg);
  padding: 2rem;
  margin-bottom: 2.5rem;
  text-align: center;
}

.converter-card h2 {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
  color: var(--secondary);
}

.converter-intro {
  font-size: 1rem;
  margin-bottom: 1.75rem;
  color: var(--muted);
}

.converter-form {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1rem;
  margin-bottom: 1.75rem;
}

.converter-result {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary);
  min-height: 1.5em;
}

/* -------------------------------------------------------------------
   Responsive Anpassungen
   ------------------------------------------------------------------- */
@media (max-width: 600px) {
  .header h1 { font-size: 2rem; }
  .feature-grid { grid-template-columns: 1fr; }
}