/**
 * style.css – Hauptstylesheet für CO₂-Rechner
 * 
 * Mobile-First Responsive Layout für eine mehrstufige CO₂-Fussabdruck-Berechnung
 * 
 * STRUKTUR:
 * 1. CSS-Variablen (Corporate Design Farben)
 * 2. Globale Styles und Reset
 * 3. Layout-Komponenten (Header, Main, Footer)
 * 4. Formular-Styles (Inputs, Buttons, Validierung)
 * 5. Mehrstufiges Formular (Navigation, Fortschritt)
 * 6. Ergebnisseite (Kreis-Animation, Kategorien, Vergleich)
 * 7. Responsive Anpassungen
 * 
 * DESIGN-PRINZIPIEN:
 * - Mobile-First Ansatz
 * - Barrierefreie Bedienung
 * - Moderne UI-Komponenten
 * - Sanfte Animationen und Übergänge
 */

/* ===== 1. CSS-VARIABLEN: CORPORATE DESIGN FARBEN ===== */
:root {
  --ice-blue: #cce9f3; /* Helles Blau für Hintergründe */
  --arktic-blue: #97d4e5; /* Mittleres Blau für Akzente */
  --ocean-blue: #00b4d8; /* Hauptfarbe für Buttons und Links */
  --midnight: #222651; /* Dunkles Blau für Text und Kontraste */
  --text-color: #222651; /* Standard-Textfarbe */
  --bg-light: #f9fafd; /* Heller Hintergrund für Container */
}

/* ===== 2. GLOBALE STYLES UND RESET ===== */
* {
  box-sizing: border-box; /* Einheitliches Box-Model */
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%; /* Vollhöhe für Flexbox-Layout */
}

body {
  font-family: "Poppins", "Montserrat", sans-serif; /* Moderne, lesbare Schriftart */
  font-size: 14px;
  color: var(--text-color);
  background-image: url("../images/gradient.webp"); /* Hintergrund-Gradient */
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  background-attachment: fixed;
  display: flex;
  flex-direction: column; /* Flexbox für Sticky Footer */
  min-height: 100vh;
  line-height: 1.5;
}

a {
  text-decoration: none;
  color: var(--bg-light); /* Standard-Linkfarbe */
}

img {
  max-width: 100%; /* Responsive Bilder */
  height: auto;
}

/* ===== 3. LAYOUT-KOMPONENTEN ===== */

/* Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  background-color: var(--bg-light);
}

.logo-container {
  display: flex;
  justify-content: center;
  width: 100%;
}

.logo-container img {
  width: 5vw; /* Responsive Logo-Grösse */
  max-width: 120px;
  min-width: 40px;
}

.site-nav a {
  font-weight: 500;
}

/* Main Content Area */
.site-main {
  max-width: 800px; /* Maximale Breite für Lesbarkeit */
  margin: 2rem auto;
  padding: 0 1rem;
  flex: 1; /* Nimmt verfügbaren Platz ein (Sticky Footer) */
}

h1 {
  font-size: 1.75rem;
  margin-bottom: 1rem;
  text-align: center;
}

.page-title {
  color: var(--bg-light);
  text-align: center;
  margin-bottom: 2rem;
}

/* ===== 4. FORMULAR-STYLES ===== */

/* Formular-Container */
form {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

fieldset {
  border: 1px solid var(--arktic-blue);
  margin-bottom: 1.5rem;
  padding: 1rem;
  border-radius: 8px;
}

legend {
  font-weight: 600;
  color: var(--midnight);
  padding: 0 0.5rem;
}

/* Standard-Labels */
label {
  display: block;
  margin-top: 0.75rem;
  margin-bottom: 0.25rem;
}

/* ===== CUSTOM RADIO BUTTONS ===== */
/* Ersetzt Standard-Radio-Buttons durch moderne, zugängliche Variante */
input[type="radio"] {
  appearance: none;
  -webkit-appearance: none;
  width: 28px;
  height: 28px;
  border: 2px solid #bbb;
  border-radius: 8px; /* Abgerundete Ecken statt Kreis */
  background: #fff;
  outline: none;
  cursor: pointer;
  position: relative;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
  margin: 0;
  box-sizing: border-box;
  display: inline-block;
  vertical-align: middle;
}

input[type="radio"]:checked {
  border-color: var(--ocean-blue);
  background: var(--ocean-blue);
  box-shadow: 0 0 0 2px rgba(0, 180, 216, 0.2);
}

input[type="radio"]:focus {
  border-color: var(--ocean-blue);
  box-shadow: 0 0 0 2px rgba(0, 180, 216, 0.3);
}

input[type="radio"]:after {
  content: "";
  display: none;
}

input[type="radio"]:checked:after {
  content: "";
  display: block;
  position: absolute;
  left: 50%;
  top: 50%;
  width: 16px;
  height: 16px;
  transform: translate(-50%, -50%);
}

input[type="radio"]:checked:after {
  /* Weisses Kreuz als Auswahlindikator */
  background: none;
}

input[type="radio"]:checked::before {
  content: "";
  display: block;
  position: absolute;
  left: 50%;
  top: 50%;
  width: 12px;
  height: 2px;
  background: #fff;
  border-radius: 1px;
  transform: translate(-50%, -50%) rotate(45deg);
}

input[type="radio"]:checked::after {
  content: "";
  display: block;
  position: absolute;
  left: 50%;
  top: 50%;
  width: 12px;
  height: 2px;
  background: #fff;
  border-radius: 1px;
  transform: translate(-50%, -50%) rotate(-45deg);
}

/* Label-Anpassung für grössere Radio-Buttons */
input[type="radio"] + label {
  margin: 0 1.5rem 0 0.25rem;
  vertical-align: middle;
  display: flex;
  align-items: center;
  height: 28px;
}

/* Barrierefreiheit: Sichtbare Fokus-Anzeige für Tastatur-Navigation */
input[type="radio"]:focus-visible {
  outline: 2px solid var(--ocean-blue);
  outline-offset: 2px;
}

/* ===== EINGABEFELDER ===== */
input[type="number"],
input[type="email"],
select,
input[type="range"] {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--ocean-blue);
  border-radius: 8px;
  font-size: 1rem;
  outline: none;
  font-family: inherit; /* Einheitliche Schriftart */
}

.error {
  color: red; /* Fehlermeldungen in Rot */
  font-size: 0.85rem;
  margin-top: 0.25rem;
  display: block;
}

/* Range-Slider Wertanzeige */
.range-value {
  display: block;
  text-align: center;
  margin-top: 0.5rem;
  font-weight: 500;
  color: var(--midnight);
}

/* ===== BUTTONS ===== */
button {
  display: block;
  width: 100%;
  padding: 0.75rem;
  background-color: var(--ocean-blue);
  color: white;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.07);
}

button:hover {
  background-color: var(--midnight);
}

/* ===== FOOTER ===== */
.site-footer {
  text-align: center;
  padding: 1rem;
  background-color: var(--bg-light);
  margin-top: 2rem;
}

/* Footer-Links sichtbar machen (überschreibt globale Link-Farbe) */
.site-footer a {
  color: var(--midnight);
  text-decoration: underline;
  font-weight: 500;
}

.site-footer a:hover {
  color: var(--ocean-blue);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (min-width: 600px) {
  form {
    padding: 2rem; /* Mehr Padding auf grösseren Bildschirmen */
  }
}

/* ===== RADIO-BUTTON GRUPPIERUNG ===== */
.radio-group {
  display: inline-flex;
  align-items: center;
  margin-right: 2rem;
  margin-bottom: 0.5rem;
  white-space: nowrap;
  gap: 0.5rem;
}

@media (max-width: 600px) {
  .radio-group {
    margin-right: 1rem;
    margin-bottom: 0.5rem;
  }

  .logo-container img {
    width: 60px;
    min-width: 40px;
    max-width: 80px;
  }
}

/* ===== CUSTOM RANGE SLIDER MIT GRADIENT ===== */
/* Moderne Range-Slider mit Fortschritts-Gradient */
input[type="range"] {
  appearance: none;
  width: 100%;
  height: 8px;
  /* CSS Custom Property --progress wird von JavaScript gesetzt */
  background: linear-gradient(90deg, #00b4d8 0%, #222651 100%) 0 /
      var(--progress, 0%) 100% no-repeat,
    #fff;
  margin: 8px 0;
  border: 1px solid var(--ocean-blue);
}

/* ===== WEBKIT BROWSER STYLES ===== */
input[type="range"]::-webkit-slider-runnable-track {
  height: 8px;
  border-radius: 8px;
  background: transparent;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
  border: 3px solid var(--ocean-blue);
  cursor: pointer;
  margin-top: -10px;
  position: relative;
  z-index: 2;
}

input[type="range"]:focus {
  outline: none;
}

input[type="range"]:focus::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px #97d4e5, 0 2px 8px rgba(0, 0, 0, 0.25);
}

/* ===== FIREFOX BROWSER STYLES ===== */
input[type="range"]::-moz-range-track {
  height: 8px;
  border-radius: 8px;
  background: transparent;
}

input[type="range"]::-moz-range-progress {
  height: 8px;
  border-radius: 8px;
  background: linear-gradient(90deg, #00b4d8 0%, #222651 100%);
}

input[type="range"]::-moz-range-thumb {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
  border: 3px solid var(--ocean-blue);
  cursor: pointer;
}

/* ===== IE/EDGE BROWSER STYLES ===== */
input[type="range"]::-ms-fill-lower {
  background: linear-gradient(90deg, #00b4d8 0%, #222651 100%);
  border-radius: 8px;
}

input[type="range"]::-ms-fill-upper {
  background: transparent;
  border-radius: 8px;
}

input[type="range"]::-ms-thumb {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.25);
  border: 3px solid var(--ocean-blue);
  cursor: pointer;
}

input[type="range"]:focus::-ms-thumb {
  box-shadow: 0 0 0 3px #97d4e5, 0 2px 8px rgba(0, 0, 0, 0.25);
}

input[type="range"]::-ms-tooltip {
  display: none;
}

input[type="range"]:focus {
  outline: none;
}

/* ===== MEHRSTUFIGES FORMULAR: NAVIGATION ===== */

/* Navigation-Container für Zurück/Weiter Buttons */
.form-navigation {
  display: flex;
  gap: 0.5rem;
  margin-top: 2rem;
}

.form-navigation .back-btn {
  flex: 1 1 33%; /* Zurück-Button nimmt 1/3 der Breite */
  background: #fff;
  color: var(--midnight);
  border: 2px solid var(--arktic-blue);
  font-weight: 700;
  font-size: 1.2rem;
  border-radius: 8px;
  padding: 1rem 0;
  cursor: pointer;
  transition: border-color 0.18s, color 0.18s, background 0.18s;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.07);
}

.form-navigation .back-btn:hover {
  background: #fff;
  border-color: var(--ocean-blue);
  color: var(--ocean-blue);
}

.form-navigation .next-btn,
.form-navigation .submit-btn {
  flex: 2 1 67%; /* Weiter/Submit-Button nimmt 2/3 der Breite */
  background: linear-gradient(90deg, var(--ocean-blue) 0%, #48d9ff 100%);
  color: #fff;
  border: none;
  font-weight: 700;
  font-size: 1.2rem;
  border-radius: 8px;
  padding: 1rem 0;
  cursor: pointer;
  transition: background 0.18s, border 0.18s, color 0.18s;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.07);
  position: relative;
  z-index: 2;
  overflow: hidden;
}

.form-navigation .next-btn::after,
.form-navigation .submit-btn::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(90deg, #00566e 0%, var(--midnight) 100%);
  opacity: 0;
  transition: opacity 0.18s;
  pointer-events: none;
}

.form-navigation .next-btn:hover::after,
.form-navigation .submit-btn:hover::after {
  opacity: 1; /* Hover-Effekt mit Overlay */
}

.form-navigation .next-btn span,
.form-navigation .submit-btn span,
.form-navigation .back-btn span {
  position: relative;
  z-index: 2; /* Text über Hover-Overlay */
}

/* ===== ERGEBNISSEITE STYLES ===== */

.results-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

/* ===== CO₂-KREIS ANZEIGE ===== */
.co2-circle {
  text-align: center;
  margin-bottom: 3rem;
}

.circle-outer {
  width: 300px; /* Desktop-Grösse */
  height: 300px;
  border-radius: 50%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: white;
}

/* Innerer Kreis bleibt über der Animation */
.circle-outer .circle-inner {
  position: relative;
  z-index: 2;
}

.circle-inner {
  width: 66.66%; /* Proportional zum äusseren Kreis */
  height: 66.66%;
  background: var(--midnight);
  border-radius: 50%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: white;
}

.circle-inner h2 {
  font-size: 2.5rem;
  margin: 0;
  font-weight: 600;
}

.circle-inner p {
  font-size: 1rem;
  margin: 0.5rem 0 0 0;
  text-align: center;
  line-height: 1.2;
}

/* ===== KATEGORIEN-AUFSCHLÜSSELUNG ===== */
.category-breakdown {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
}

.category-breakdown h2 {
  color: var(--ocean-blue);
  font-size: 1.5rem;
  margin-bottom: 2rem;
  font-weight: 600;
}

.category-item {
  margin-bottom: 1.5rem;
}

.category-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.category-name {
  font-weight: 500;
  color: var(--midnight);
  font-size: 1.1rem;
}

.category-value {
  font-weight: 600;
  color: var(--midnight);
  font-size: 1.1rem;
}

.category-bar {
  height: 12px;
  background: var(--ice-blue);
  border-radius: 8px;
  overflow: hidden;
}

.bar-fill {
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--ocean-blue) 0%,
    var(--midnight) 100%
  );
  border-radius: 8px;
  transition: width 0.8s ease-in-out;
}

/* ===== VERGLEICHSSEKTION ===== */
.comparison-section {
  background: var(--ice-blue);
  padding: 2rem;
  border-radius: 8px;
  margin-bottom: 2rem;
}

.comparison-section h2 {
  color: var(--ocean-blue);
  font-size: 1.5rem;
  margin-bottom: 2rem;
  font-weight: 600;
}

.comparison-stats {
  display: flex;
  align-items: center;
  justify-content: space-around;
  text-align: center;
}

.comparison-item {
  flex: 1;
}

.percentage {
  font-size: 3rem;
  font-weight: 700;
  color: var(--midnight);
  margin-bottom: 0.5rem;
}

.average-value {
  font-size: 3rem;
  font-weight: 700;
  color: var(--midnight);
  margin-bottom: 0.5rem;
}

.comparison-divider {
  width: 2px;
  height: 80px;
  background: var(--arktic-blue);
  margin: 0 2rem;
}

.comparison-item p {
  color: var(--midnight);
  font-weight: 500;
  margin: 0;
  line-height: 1.3;
}

/* ===== ERGEBNIS-AKTIONEN ===== */
.results-actions {
  text-align: center;
}

.back-to-form {
  display: inline-block;
  padding: 1rem 2rem;
  background: var(--ocean-blue);
  color: white;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  transition: background 0.2s;
}

.back-to-form:hover {
  background: var(--midnight);
  color: white;
}

/* Sekundärer Button für Broschüre-Link */
.secondary-action-btn {
  display: inline-block;
  padding: 1rem 2rem;
  background: #fff;
  color: var(--midnight);
  border: 2px solid var(--arktic-blue);
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  transition: border-color 0.18s, color 0.18s, background 0.18s;
  margin-top: 1rem;
  text-align: center;
}

.secondary-action-btn:hover {
  background: #fff;
  border-color: var(--ocean-blue);
  color: var(--ocean-blue);
}

.secondary-action-btn .icon {
  margin-right: 0.5rem;
  font-weight: bold;
}

/* ===== RESPONSIVE ANPASSUNGEN FÜR ERGEBNISSE ===== */
@media (max-width: 600px) {
  .circle-outer {
    width: 250px; /* Mobile Kreis-Grösse */
    height: 250px;
  }

  .circle-inner {
    /* Proportionale Grösse wird automatisch berechnet */
  }

  .circle-inner h2 {
    font-size: 2rem;
  }

  .comparison-stats {
    flex-direction: column;
    gap: 2rem;
  }

  .comparison-divider {
    width: 80%;
    height: 2px;
    margin: 0;
  }

  .percentage,
  .average-value {
    font-size: 2.5rem;
  }
}

/* ===== EINGABEFELD FOKUS-STYLES ===== */
input[type="number"]:focus,
input[type="email"]:focus,
select:focus {
  border-color: var(--ocean-blue);
  box-shadow: 0 0 0 2px rgba(0, 180, 216, 0.2);
}

input[type="number"] {
  text-align: center; /* Zahlen zentriert anzeigen */
}

/* ===== FORTSCHRITTSBALKEN ===== */
.form-progress {
  margin-bottom: 2rem;
  text-align: center;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: #f0f0f0;
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 0.5rem;
  position: relative;
}

.progress-fill {
  height: 100%;
  width: 25%; /* Initial: 25% (Schritt 1 von 4) */
  background: linear-gradient(90deg, #00b4d8 0%, #222651 100%);
  border-radius: 8px;
  transition: width 0.3s ease;
  position: relative;
}