.start-screen {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px;
}

.start-card {
  width: min(860px, 96vw);
  padding: 42px;
  border-radius: 28px;
}

.brand-mark {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  color: white;
  font-size: 24px;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: 0 18px 50px rgba(31,78,121,.18);
}

.brand-mark.small {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  font-size: 18px;
}

.start-card h1 {
  margin: 18px 0 8px;
  font-size: clamp(32px, 5vw, 56px);
  letter-spacing: .03em;
}

.lead {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.start-actions {
  display: flex;
  gap: 12px;
  margin: 28px 0 0;
}

.main-screen {
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 20px;
  background: rgba(255,255,255,.78);
  border-right: 1px solid rgba(231,234,241,.9);
  backdrop-filter: blur(18px);
}

.sidebar-logo {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-bottom: 26px;
}

.sidebar-logo span {
  display: block;
  color: var(--muted);
  font-size: 12px;
  margin-top: 2px;
}

.nav {
  display: grid;
  gap: 8px;
  margin-bottom: 20px;
}

.nav-group {
  margin: 16px 0 4px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: .12em;
}

.nav-btn {
  width: 100%;
  padding: 12px 12px;
  border-radius: 14px;
  text-align: left;
  background: transparent;
  color: #334155;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-btn.active {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 8px 24px rgba(23,32,51,.07);
}

.workspace {
  padding: 22px 26px 50px;
  overflow-x: hidden;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  margin-bottom: 20px;
}

.topbar h2 {
  margin: 0 0 4px;
  font-size: 28px;
}

.topbar p {
  margin: 0;
  color: var(--muted);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.view { display: none; }
.view.active { display: block; }

.panel {
  background: var(--panel-solid);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 18px 44px rgba(23,32,51,.06);
  padding: 22px;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 18px;
}

.section-head h3,
.section-head h2 {
  margin: 0 0 5px;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(260px, 1fr));
  gap: 16px;
}

.span-2 { grid-column: span 2; }

.panel-actions {
  margin-top: 20px;
  display: flex;
  justify-content: flex-end;
}

.placeholder-view .panel {
  min-height: 430px;
  display: grid;
  place-items: center;
  text-align: center;
}

@media (max-width: 900px) {
  .main-screen { grid-template-columns: 1fr; }
  .sidebar { position: relative; height: auto; }
  .topbar { flex-direction: column; align-items: flex-start; }
  .form-grid { grid-template-columns: 1fr; }
  .span-2 { grid-column: span 1; }
}