/* ============================================================
   E-Rechnung Generator — Custom Design System
   Kein CSS-Framework. Kein Build-Step.
   ============================================================ */

/* === Custom Properties === */
:root {
  --clr-primary:        #2563EB;
  --clr-primary-hover:  #1D4ED8;
  --clr-primary-ring:   rgba(37, 99, 235, 0.25);
  --clr-success-text:   #166534;
  --clr-success-bg:     #F0FDF4;
  --clr-success-border: #86EFAC;
  --clr-error-text:     #991B1B;
  --clr-error-bg:       #FEF2F2;
  --clr-error-border:   #FCA5A5;
  --clr-bg:             #F4F7FB;
  --clr-surface:        #FFFFFF;
  --clr-text:           #1E293B;
  --clr-muted:          #64748B;
  --clr-border:         #D1D9E6;
  --clr-nav-bg:         #1E40AF;
  --clr-nav-text:       #FFFFFF;
  --clr-nav-accent:     rgba(255,255,255,0.14);
  --clr-footer-bg:      #1E293B;
  --clr-footer-text:    #94A3B8;

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  14px;

  --shadow-card: 0 1px 3px rgba(0,0,0,.08), 0 4px 16px rgba(0,0,0,.06);
  --shadow-btn:  0 1px 2px rgba(37,99,235,.3);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  --transition: 150ms ease;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--clr-text);
  background: var(--clr-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--clr-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button, input { font-family: inherit; font-size: inherit; }

/* === Page Layout === */
.page-wrapper { display: flex; flex-direction: column; min-height: 100vh; }
.page-main    { flex: 1; }

.container {
  width: 100%;
  max-width: 680px;
  margin-inline: auto;
  padding-inline: 20px;
}

/* === Navbar === */
.site-nav {
  background: var(--clr-nav-bg);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 4px rgba(0,0,0,.25);
}
.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 58px;
  max-width: 1100px;
  margin-inline: auto;
  padding-inline: 20px;
}
.site-nav__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--clr-nav-text);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
}
.site-nav__brand:hover { text-decoration: none; opacity: .9; }
.site-nav__brand-icon {
  width: 30px; height: 30px;
  background: rgba(255,255,255,0.15);
  border-radius: 7px;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.site-nav__brand-icon svg { width: 16px; height: 16px; fill: #fff; }

.site-nav__links {
  display: flex;
  list-style: none;
  gap: 4px;
}
.site-nav__links a {
  display: block;
  padding: 6px 14px;
  color: rgba(255,255,255,0.80);
  font-size: .9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
  text-decoration: none;
}
.site-nav__links a:hover,
.site-nav__links a.active {
  background: var(--clr-nav-accent);
  color: #fff;
}

/* === Hero === */
.hero {
  padding: 56px 20px 36px;
  text-align: center;
}
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(37,99,235,.09);
  color: #1D4ED8;
  font-size: .72rem;
  font-weight: 400;
  letter-spacing: .04em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 20px;
}
.hero__badge svg { width: 13px; height: 13px; fill: currentColor; flex-shrink: 0; }
.hero__title {
  font-size: clamp(1.35rem, 3.5vw, 1.75rem);
  font-weight: 500;
  letter-spacing: -0.025em;
  line-height: 1.2;
  color: var(--clr-text);
  margin-bottom: 14px;
}
.hero__sub {
  font-size: .975rem;
  color: var(--clr-muted);
  max-width: 520px;
  margin-inline: auto;
  line-height: 1.65;
}

/* === Upload Card === */
.upload-card {
  background: var(--clr-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 36px 40px 32px;
  margin-bottom: 32px;
}
.upload-card__title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--clr-text);
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--clr-border);
}

/* === File Zone === */
.file-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 2px dashed var(--clr-border);
  border-radius: var(--radius-md);
  padding: 32px 20px;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  background: #FAFBFD;
  margin-bottom: 20px;
  text-align: center;
}
.file-zone:hover,
.file-zone.drag-over {
  border-color: var(--clr-primary);
  background: rgba(37,99,235,.04);
}
.file-zone__icon {
  width: 40px; height: 40px;
  color: var(--clr-muted);
  margin-bottom: 4px;
}
.file-zone__icon svg { width: 40px; height: 40px; stroke: currentColor; fill: none; }
.file-zone__label {
  font-size: .95rem;
  font-weight: 600;
  color: var(--clr-primary);
}
.file-zone__hint {
  font-size: .82rem;
  color: var(--clr-muted);
}
.file-zone__name {
  font-size: .85rem;
  font-weight: 600;
  color: var(--clr-text);
  background: rgba(37,99,235,.07);
  padding: 3px 10px;
  border-radius: 4px;
  display: none;
}
.file-zone__name.visible { display: inline-block; }
.file-zone__input {
  position: absolute;
  width: 1px; height: 1px;
  opacity: 0; overflow: hidden;
  clip: rect(0,0,0,0);
}

.upload-hint {
  font-size: .82rem;
  color: var(--clr-muted);
  margin-bottom: 22px;
  line-height: 1.5;
}

/* === Primary Button === */
.btn-generate {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 14px 20px;
  background: var(--clr-primary);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
  letter-spacing: .01em;
}
.btn-generate:hover:not(:disabled) {
  background: var(--clr-primary-hover);
  box-shadow: 0 2px 6px rgba(27,58,107,.4);
  transform: translateY(-1px);
}
.btn-generate:active:not(:disabled) {
  transform: translateY(0);
}
.btn-generate:disabled {
  background: #94A3B8;
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}
.btn-generate svg {
  width: 18px; height: 18px;
  fill: currentColor;
  flex-shrink: 0;
}

/* === Spinner === */
.spinner {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-top: 20px;
  font-size: .9rem;
  color: var(--clr-muted);
  font-weight: 500;
}
.spinner.active { display: flex; }
.spinner__ring {
  width: 20px; height: 20px;
  border: 2.5px solid #E2E8F0;
  border-top-color: var(--clr-primary);
  border-radius: 50%;
  flex-shrink: 0;
  animation: spin .75s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* === Alerts === */
.alert {
  margin-top: 18px;
  padding: 13px 16px;
  border-radius: var(--radius-sm);
  font-size: .9rem;
  line-height: 1.5;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.alert svg { width: 18px; height: 18px; flex-shrink: 0; margin-top: 1px; }
.alert[hidden] { display: none; }

.alert--error {
  background: var(--clr-error-bg);
  border: 1px solid var(--clr-error-border);
  color: var(--clr-error-text);
  border-left: 4px solid #EF4444;
}
.alert--error svg { stroke: #EF4444; fill: none; }

.alert--success {
  background: var(--clr-success-bg);
  border: 1px solid var(--clr-success-border);
  color: var(--clr-success-text);
  border-left: 4px solid #22C55E;
}
.alert--success svg { stroke: #22C55E; fill: none; }

/* === Trust badges === */
.trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
  list-style: none;
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--clr-border);
  justify-content: center;
}
.trust-list li {
  font-size: .78rem;
  color: var(--clr-muted);
  display: flex;
  align-items: center;
  gap: 5px;
}
.trust-list li::before {
  content: '';
  display: inline-block;
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #22C55E;
  flex-shrink: 0;
}

/* === Footer === */
.site-footer {
  background: var(--clr-footer-bg);
  color: var(--clr-footer-text);
  text-align: center;
  font-size: .8rem;
  padding: 18px 20px;
  margin-top: auto;
}
.site-footer a {
  color: var(--clr-footer-text);
  text-decoration: underline;
  opacity: .8;
}
.site-footer a:hover { opacity: 1; }

/* === Responsive === */
@media (max-width: 600px) {
  .upload-card { padding: 24px 20px 20px; }
  .hero { padding: 36px 16px 24px; }
  .trust-list { flex-direction: column; align-items: center; }
}