/**
 * K24AI Landing Page v2 - Styles
 * Based on FE-03 Brand Guide
 */

/* ========================================
   CSS Variables (Brand Guide)
   ======================================== */
:root {
  /* Primary Colors */
  --primary: #1e40af;
  --primary-light: #3b82f6;

  /* Accent Colors */
  --accent-cyan: #06b6d4;
  --accent-orange: #f59e0b;

  /* Status Colors */
  --status-success: #10b981;
  --status-error: #ef4444;
  --status-warning: #f59e0b;
  --status-neutral: #6b7280;

  /* Light Mode */
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --border-color: #e5e7eb;

  /* Spacing */
  --header-height: 64px;
  --container-max: 1280px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;

  /* Typography */
  --font-family: system-ui, -apple-system, "Inter", sans-serif;
  --font-mono: "Consolas", "Monaco", monospace;
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --border-color: #334155;
}

/* ========================================
   Reset & Base
   ======================================== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition:
    background-color 0.3s ease,
    color 0.3s ease;
}

a {
  color: var(--primary-light);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary);
}

img {
  max-width: 100%;
  height: auto;
}

/* ========================================
   Layout
   ======================================== */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.125rem;
  text-align: center;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 3rem;
}

/* ========================================
   Header
   ======================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition:
    background-color 0.3s ease,
    border-color 0.3s ease;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}

.logo-icon {
  width: 32px;
  height: 32px;
}

.logo-text {
  color: var(--text-primary);
}

.logo-text span {
  color: var(--primary);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Language Switcher */
.lang-switcher {
  display: flex;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.lang-btn {
  padding: 0.5rem 0.75rem;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}

.lang-btn:hover {
  color: var(--text-primary);
}

.lang-btn.active {
  background-color: var(--primary);
  color: #ffffff;
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color 0.2s ease;
  border: 1px solid var(--border-color);
}

.theme-toggle:hover {
  background-color: var(--border-color);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  color: var(--text-primary);
}

.theme-toggle .sun-icon {
  display: none;
}

.theme-toggle .moon-icon {
  display: block;
}

[data-theme="dark"] .theme-toggle .sun-icon {
  display: block;
}

[data-theme="dark"] .theme-toggle .moon-icon {
  display: none;
}

/* CTA Button */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
  border: none;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--primary-light);
  color: #ffffff;
}

.btn-accent {
  background-color: var(--accent-orange);
  color: #ffffff;
}

.btn-accent:hover {
  background-color: #d97706;
  color: #ffffff;
}

.btn-outline {
  background-color: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background-color: var(--primary);
  color: #ffffff;
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
  padding-top: calc(var(--header-height) + 4rem);
  padding-bottom: 5rem;
  background-color: var(--bg-secondary);
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background-color: var(--primary);
  color: #ffffff;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.hero-title span {
  color: var(--primary);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.hero-cta {
  display: inline-flex;
  gap: 1rem;
}

/* ========================================
   Problem Section
   ======================================== */
.problem {
  background-color: var(--bg-primary);
}

.problem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.problem-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.problem-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.problem-stat {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--status-error);
  margin-bottom: 0.5rem;
}

.problem-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.problem-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

/* ========================================
   Solution Section
   ======================================== */
.solution {
  background-color: var(--bg-secondary);
}

.solution-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.solution-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.solution-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.solution-icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-light) 100%
  );
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 1.75rem;
}

.solution-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.solution-card p {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin-bottom: 1rem;
}

.solution-stat {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--status-success);
}

/* ========================================
   Trust Section
   ======================================== */
.trust {
  background-color: var(--bg-primary);
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.trust-item {
  text-align: center;
  padding: 1.5rem;
}

.trust-icon {
  width: 48px;
  height: 48px;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-size: 1.5rem;
  border: 1px solid var(--border-color);
}

.trust-item h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.trust-item p {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ========================================
   Alpha CTA Section
   ======================================== */
.alpha {
  background: linear-gradient(
    135deg,
    var(--primary) 0%,
    var(--primary-light) 100%
  );
  color: #ffffff;
}

.alpha .section-title,
.alpha .section-subtitle {
  color: #ffffff;
}

.alpha .section-subtitle {
  opacity: 0.9;
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.benefit-item {
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.benefit-icon {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
}

.benefit-item h4 {
  font-size: 0.9375rem;
  font-weight: 600;
}

/* Form Styles */
.alpha-form {
  max-width: 600px;
  margin: 0 auto;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  font-size: 0.875rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-md);
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  font-size: 1rem;
  font-family: inherit;
  transition:
    border-color 0.2s ease,
    background-color 0.2s ease;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: rgba(255, 255, 255, 0.6);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: #ffffff;
  background-color: rgba(255, 255, 255, 0.15);
}

.form-group select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='white' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

.form-group select option {
  background-color: var(--primary);
  color: #ffffff;
}

.form-submit {
  width: 100%;
  padding: 1rem 2rem;
  background-color: #ffffff;
  color: var(--primary);
  font-size: 1rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.form-submit:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.form-submit:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  transform: none;
}

.form-message {
  text-align: center;
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-top: 1rem;
  display: none;
}

.form-message.success {
  display: block;
  background-color: rgba(16, 185, 129, 0.2);
  border: 1px solid var(--status-success);
}

.form-message.error {
  display: block;
  background-color: rgba(239, 68, 68, 0.2);
  border: 1px solid var(--status-error);
}

/* ========================================
   Footer
   ======================================== */
.footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-brand .logo-icon {
  width: 24px;
  height: 24px;
}

.footer-tagline {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--text-primary);
}

.footer-copyright {
  text-align: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
  .problem-grid,
  .solution-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .trust-grid,
  .benefits-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .problem-grid,
  .solution-grid,
  .trust-grid,
  .benefits-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .header-nav {
    display: none;
  }

  .footer-content {
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
  }

  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 1rem;
  }

  .section {
    padding: 3rem 0;
  }

  .hero {
    padding-top: calc(var(--header-height) + 2rem);
    padding-bottom: 3rem;
  }

  .hero-cta {
    flex-direction: column;
  }

  .alpha-form {
    padding: 1.5rem;
  }
}

/* ========================================
   Legal Pages (Impressum, Datenschutz)
   ======================================== */
.legal-page {
  padding-top: calc(var(--header-height) + 3rem);
  padding-bottom: 4rem;
  min-height: calc(100vh - 200px);
}

.back-link {
  display: inline-flex;
  align-items: center;
  color: var(--primary-light);
  font-size: 0.875rem;
  margin-bottom: 2rem;
  transition: color 0.2s ease;
}

.back-link:hover {
  color: var(--primary);
}

[data-theme="dark"] .back-link {
  color: var(--accent-cyan);
}

[data-theme="dark"] .back-link:hover {
  color: var(--primary-light);
}

.legal-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2.5rem;
  line-height: 1.2;
}

.legal-content {
  max-width: 800px;
}

.legal-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--border-color);
}

.legal-content h2:first-child {
  margin-top: 0;
}

.legal-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

.legal-section {
  margin-bottom: 1.5rem;
}

.legal-section p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.legal-section p:last-child {
  margin-bottom: 0;
}

.legal-section ul {
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0.75rem 0;
  padding-left: 1.5rem;
}

.legal-section li {
  margin-bottom: 0.5rem;
}

.legal-section a {
  color: var(--primary-light);
  text-decoration: underline;
  transition: color 0.2s ease;
}

.legal-section a:hover {
  color: var(--primary);
}

[data-theme="dark"] .legal-section a {
  color: var(--accent-cyan);
}

[data-theme="dark"] .legal-section a:hover {
  color: var(--primary-light);
}

.legal-section strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* Legal Page Responsive */
@media (max-width: 768px) {
  .legal-title {
    font-size: 1.75rem;
  }

  .legal-content h2 {
    font-size: 1.25rem;
  }

  .legal-content h3 {
    font-size: 1rem;
  }
}

@media (max-width: 640px) {
  .legal-page {
    padding-top: calc(var(--header-height) + 2rem);
    padding-bottom: 3rem;
  }

  .legal-title {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
  }
}