:root {
  --qd-primary: #4f6f52;
  --qd-accent: #c95f4a;
  --qd-ink: #1f2937;
  --qd-soft: #f4f1ea;
}

[data-bs-theme="light"] {
  --bs-primary: var(--qd-primary);
  --bs-primary-rgb: 79, 111, 82;
  --bs-body-bg: #f7f4ee;
  --bs-body-color: var(--qd-ink);
}

[data-bs-theme="dark"] {
  --bs-primary: #89a98c;
  --bs-primary-rgb: 137, 169, 140;
  --bs-body-bg: #111827;
  --bs-body-color: #eef2f7;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(201, 95, 74, 0.18), transparent 32rem),
    radial-gradient(circle at bottom right, rgba(79, 111, 82, 0.2), transparent 30rem),
    var(--bs-body-bg);
}

.brand-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 0.5rem;
  display: inline-grid;
  place-items: center;
  background: var(--qd-primary);
  color: #fff;
  font-size: 0.78rem;
  letter-spacing: 0;
}

.hero-card,
.app-card {
  border-radius: 1rem;
  background: color-mix(in srgb, var(--bs-body-bg) 84%, var(--bs-card-bg));
  backdrop-filter: blur(18px);
}

.hero-card {
  overflow: hidden;
}

.hero-card::before {
  content: "";
  display: block;
  height: 0.35rem;
  background: linear-gradient(90deg, var(--qd-primary), var(--qd-accent));
}

.view {
  display: none;
  animation: view-in 0.24s ease both;
}

.view.active {
  display: block;
}

@keyframes view-in {
  from {
    opacity: 0;
    transform: translateY(0.5rem);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.stat-mini {
  background: rgba(var(--bs-primary-rgb), 0.08);
}

.stat-mini strong,
.stat-card strong {
  display: block;
  color: var(--bs-primary);
  font-size: 1.35rem;
  line-height: 1;
}

.stat-mini span,
.stat-card span,
.secret-box span {
  display: block;
  color: var(--bs-secondary-color);
  font-size: 0.78rem;
  margin-top: 0.35rem;
}

.step-dot {
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  color: #fff;
  background: var(--qd-accent);
  font-weight: 700;
  font-size: 0.82rem;
}

.feature-card {
  border-color: var(--bs-border-color);
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}

.feature-card:hover {
  transform: translateY(-0.15rem);
  border-color: rgba(var(--bs-primary-rgb), 0.45);
  box-shadow: 0 0.75rem 1.75rem rgba(15, 23, 42, 0.08);
}

.letter-input {
  min-height: 16rem;
  resize: vertical;
}

.form-floating > textarea.letter-input {
  min-height: 16rem;
}

.code-field {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 800;
}

.secret-box strong,
.copy-link {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  word-break: break-all;
}

.secret-box strong {
  display: block;
  margin-top: 0.45rem;
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  letter-spacing: 0.08em;
}

.letter-card p {
  margin: 0;
  white-space: pre-wrap;
  line-height: 1.7;
}

.stat-card {
  border: 1px solid var(--bs-border-color);
  border-radius: var(--bs-border-radius-lg);
  background: var(--bs-card-bg);
  padding: 1rem;
}

.ad-banner,
.ad-slot {
  border-radius: 1rem;
  color: var(--bs-secondary-color);
  background:
    linear-gradient(135deg, rgba(var(--bs-primary-rgb), 0.1), rgba(201, 95, 74, 0.08)),
    var(--bs-card-bg);
}

.ad-banner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 5rem;
  text-align: center;
}

.ad-slot {
  min-height: 5.5rem;
  display: grid;
  place-items: center;
  border: 1px dashed rgba(var(--bs-primary-rgb), 0.45);
  padding: 1rem;
  text-align: center;
}

.btn-primary {
  --bs-btn-bg: var(--qd-primary);
  --bs-btn-border-color: var(--qd-primary);
  --bs-btn-hover-bg: #405b43;
  --bs-btn-hover-border-color: #405b43;
}

.btn-outline-primary {
  --bs-btn-color: var(--qd-primary);
  --bs-btn-border-color: var(--qd-primary);
  --bs-btn-hover-bg: var(--qd-primary);
  --bs-btn-hover-border-color: var(--qd-primary);
}

[data-bs-theme="dark"] .btn-primary {
  --bs-btn-bg: #89a98c;
  --bs-btn-border-color: #89a98c;
  --bs-btn-color: #111827;
  --bs-btn-hover-bg: #9bb69d;
  --bs-btn-hover-border-color: #9bb69d;
}

[data-bs-theme="dark"] .btn-outline-primary {
  --bs-btn-color: #9bb69d;
  --bs-btn-border-color: #9bb69d;
  --bs-btn-hover-bg: #9bb69d;
  --bs-btn-hover-border-color: #9bb69d;
  --bs-btn-hover-color: #111827;
}

@media (max-width: 575.98px) {
  .navbar-brand span:not(.brand-mark):not(.badge) {
    max-width: 9rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .input-group.input-group-lg {
    flex-direction: column;
  }

  .input-group.input-group-lg > * {
    width: 100%;
    border-radius: var(--bs-border-radius) !important;
    margin-top: 0.4rem;
  }

  .ad-banner {
    flex-direction: column;
  }
}