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

:root {
  --black:    #0a0a0a;
  --dark:     #111111;
  --card:     #1a1a1a;
  --border:   #2a2a2a;
  --muted:    #444444;
  --text:     #e8e8e8;
  --sub:      #909090;
  --accent:   #ff5c00;
  --accent2:  #ff7a2a;
  --green:    #22c55e;
  --green-bg: #0d2b1a;
  --radius:   10px;
  --font:     'Inter', system-ui, -apple-system, sans-serif;
}

body {
  background: var(--black);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  min-height: 100vh;
  position: relative;
}

/* ── Site-wide background image ──────────────────────────────────────────────── */
.site-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100vh;
  background-image: url('../assets/images/Exoskeleton von German Bionic.avif');
  background-size: cover;
  background-position: left center;
  z-index: 0;
}

.site-bg-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(to left,  rgba(10,10,10,0.92) 0%, rgba(10,10,10,0.4) 48%, transparent 72%),
    linear-gradient(to bottom, rgba(10,10,10,0.1)  0%, rgba(10,10,10,0.82) 62%, rgba(10,10,10,1) 85%);
}

@media (min-width: 768px)  { body { font-size: 18px; } }
@media (min-width: 1280px) { body { font-size: 19px; } }

/* ── Header ─────────────────────────────────────────────────────────────────── */
header {
  background: rgba(10,10,10,0.45);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  padding: 16px 40px;
  display: flex;
  align-items: center;
  gap: 20px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo-img {
  height: 44px;
  width: auto;
  display: block;
  flex-shrink: 0;
}

.header-divider {
  width: 1px;
  height: 22px;
  background: var(--border);
  flex-shrink: 0;
}

.header-subtitle {
  font-size: 13px;
  color: var(--sub);
  font-weight: 500;
  white-space: nowrap;
}

/* ── Language Switcher ───────────────────────────────────────────────────────── */
.lang-switcher {
  display: flex;
  gap: 4px;
  margin-left: auto;
}

.lang-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--sub);
  border-radius: 6px;
  padding: 5px 11px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: all .15s;
  letter-spacing: 0.5px;
  font-family: var(--font);
}

.lang-btn:hover { color: var(--text); border-color: var(--muted); }
.lang-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ── Layout ──────────────────────────────────────────────────────────────────── */
.page { max-width: 980px; margin: 0 auto; padding: 52px 24px 80px; position: relative; z-index: 1; }

/* ── Hero ────────────────────────────────────────────────────────────────────── */
.hero {
  min-height: 460px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  margin-bottom: 48px;
}

.hero-text {
  padding: 60px 0;
  max-width: 520px;
  text-align: right;
}

.hero-text h1 {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -1px;
  line-height: 1.18;
  margin-bottom: 16px;
}

@media (min-width: 768px)  { .hero-text h1 { font-size: 46px; } }
@media (min-width: 1280px) { .hero-text h1 { font-size: 52px; } }

.hero-accent { color: var(--accent); }

.hero-text p {
  color: var(--sub);
  font-size: 17px;
  line-height: 1.7;
}

@media (min-width: 768px) { .hero-text p { font-size: 18px; } }

@media (max-width: 768px) {
  .hero {
    min-height: 380px;
    align-items: flex-end;
    justify-content: flex-start;
  }
  .hero-text {
    padding: 32px 0;
    max-width: 100%;
    text-align: left;
  }
  .site-bg { background-position: 30% center; }
}

/* ── Cards ───────────────────────────────────────────────────────────────────── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  margin-bottom: 20px;
}

.card-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 22px;
}

/* ── Grid ────────────────────────────────────────────────────────────────────── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 16px; }

@media (max-width: 640px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
}

/* ── Form ────────────────────────────────────────────────────────────────────── */
label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--sub);
  margin-bottom: 8px;
  letter-spacing: 0.2px;
}

select, input[type=number] {
  width: 100%;
  background: #222;
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 8px;
  padding: 12px 14px;
  font-size: 16px;
  transition: border-color .15s;
  appearance: none;
  font-family: var(--font);
}

select {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23909090' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
}

select:focus, input:focus { outline: none; border-color: var(--accent); }
input.invalid { background-color: #f87171; color: #fff; border-color: #f87171; }
input.invalid:focus { background-color: #f87171; color: #fff; border-color: #f87171; }

/* ── Device Stepper ──────────────────────────────────────────────────────────── */
.stepper {
  display: flex;
  align-items: center;
  background: #222;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  transition: border-color .15s;
  height: 44px;
}

.stepper:focus-within { border-color: var(--accent); }

.stepper-btn {
  background: none;
  border: none;
  color: var(--sub);
  width: 44px;
  height: 44px;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
  transition: background .15s, color .15s;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-family: var(--font);
}

.stepper-btn:hover { background: rgba(255,255,255,.07); color: var(--text); }
.stepper-btn:active { background: rgba(255,255,255,.12); }

.stepper-val {
  flex: 1;
  text-align: center;
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  user-select: none;
}

/* ── Slider ──────────────────────────────────────────────────────────────────── */
.slider-wrap { display: flex; align-items: center; gap: 14px; }

input[type=range] {
  flex: 1;
  appearance: none;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  cursor: pointer;
}

input[type=range]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  transition: transform .1s;
}

input[type=range]::-webkit-slider-thumb:hover { transform: scale(1.2); }
input[type=range]::-moz-range-thumb:hover      { transform: scale(1.2); }

#lifespan::-webkit-slider-thumb { background: var(--green); }
#lifespan::-moz-range-thumb      { background: var(--green); }

.slider-val {
  min-width: 44px;
  text-align: center;
  background: #222;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 15px;
  font-weight: 700;
}

/* ── Advanced Toggle ─────────────────────────────────────────────────────────── */
.advanced-toggle {
  background: none;
  border: none;
  color: var(--sub);
  font-size: 13px;
  cursor: pointer;
  padding: 12px 0 2px;
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font);
}

.advanced-toggle:hover { color: var(--text); }
.toggle-icon { transition: transform .2s ease; flex-shrink: 0; }
.advanced-fields { display: none; margin-top: 18px; }
.advanced-fields.show { display: grid; }

/* ── Result Card ─────────────────────────────────────────────────────────────── */
.result-card {
  background: var(--green-bg);
  border: 1px solid var(--green);
  border-radius: var(--radius);
  padding: 36px 32px 28px;
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}

.result-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--green), #4ade80);
}

.result-tag {
  display: inline-block;
  background: rgba(34,197,94,.15);
  border: 1px solid rgba(34,197,94,.3);
  border-radius: 20px;
  padding: 3px 12px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--green);
  margin-bottom: 18px;
}

.result-main { display: flex; align-items: baseline; gap: 8px; margin-bottom: 6px; }

.result-number {
  font-size: 70px;
  font-weight: 900;
  letter-spacing: -3px;
  line-height: 1;
  color: #fff;
}

.result-currency { font-size: 32px; font-weight: 700; color: var(--green); }

.result-period { font-size: 17px; color: var(--sub); margin-bottom: 8px; }

.result-amort {
  font-size: 14px;
  color: var(--sub);
  background: rgba(255,255,255,.04);
  border-radius: 6px;
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 28px;
}

.result-amort span { color: var(--text); font-weight: 600; }

/* ── Breakdown ───────────────────────────────────────────────────────────────── */
.breakdown {
  border-top: 1px solid rgba(255,255,255,.08);
  padding-top: 24px;
}

.breakdown-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

@media (max-width: 640px) { .breakdown-grid { grid-template-columns: 1fr 1fr; } }

.bd-label {
  font-size: 11px;
  color: var(--sub);
  text-transform: uppercase;
  letter-spacing: .8px;
  margin-bottom: 4px;
  font-weight: 700;
}

.bd-value { font-size: 20px; font-weight: 700; }
.bd-value.neg  { color: #f87171; }
.bd-value.pos  { color: var(--green); }
.bd-value.mult { color: #a78bfa; }
.bd-note { font-size: 12px; color: var(--sub); margin-top: 2px; }

/* ── Coverage Bar ────────────────────────────────────────────────────────────── */
.coverage-wrap {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid rgba(255,255,255,.08);
}

.coverage-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.coverage-title {
  font-size: 11px;
  color: var(--sub);
  text-transform: uppercase;
  letter-spacing: .8px;
  font-weight: 700;
}

.coverage-track {
  height: 6px;
  background: rgba(255,255,255,.08);
  border-radius: 3px;
  overflow: hidden;
}

.coverage-bar {
  height: 100%;
  border-radius: 3px;
  transition: width .4s ease, background .4s;
}

.coverage-hint {
  font-size: 12px;
  color: #fbbf24;
  margin-top: 10px;
  display: none;
}

/* ── Qualitative List ────────────────────────────────────────────────────────── */
.qual-list { list-style: none; }

.qual-list li {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  font-size: 15px;
  color: var(--sub);
}

.qual-list li:last-child { border-bottom: none; }

.qual-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  background: #1f1f1f;
  border: 1px solid var(--border);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  margin-top: 1px;
}

.qual-list li strong { color: var(--text); }

/* ── Disclaimer ──────────────────────────────────────────────────────────────── */
.disclaimer {
  background: #111;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  font-size: 13px;
  color: #666;
  line-height: 1.7;
}

.source-grid { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }

.source-badge {
  background: #1a1a1a;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 3px 9px;
  font-size: 11px;
  color: var(--sub);
}

/* ── Animation ───────────────────────────────────────────────────────────────── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}
.animate { animation: fadeIn .3s ease; }

/* ── Footer ──────────────────────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  background: var(--dark);
  padding: 36px 40px;
  position: relative;
  z-index: 1;
}

.footer-inner {
  max-width: 980px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.footer-top {
  display: flex;
  align-items: center;
  gap: 16px;
}

.footer-logo {
  height: 26px;
  width: auto;
  opacity: 0.8;
}

.footer-tagline {
  font-size: 13px;
  color: var(--sub);
  padding-left: 16px;
  border-left: 1px solid var(--border);
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 13px;
  color: var(--sub);
  text-decoration: none;
  transition: color .15s;
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 12px;
  color: #555;
}

.footer-sep { color: #333; }

@media (max-width: 560px) {
  footer { padding: 28px 20px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; gap: 4px; }
  .footer-sep { display: none; }
}

/* ── Mobile Header ───────────────────────────────────────────────────────────── */
@media (max-width: 560px) {
  header { padding: 14px 20px; gap: 12px; }
  .header-subtitle { display: none; }
  .header-divider  { display: none; }
  .page { padding: 32px 16px 60px; }
  .card { padding: 22px 20px; }
  .result-card { padding: 28px 20px 22px; }
  .result-number { font-size: 52px; }
}