#app {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding-top: var(--safe-top);
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
  background: var(--bg-primary);
}

.view {
  display: none;
  flex: 1;
  overflow: hidden;
}

.view.active {
  display: flex;
  flex-direction: column;
}

/* Login */
#login-view.active,
#admin-view.active.login-view {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  height: 100%;
  padding: 24px;
  padding-bottom: calc(8px + var(--safe-bottom));
  position: relative;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  background-color: var(--bg-surface);
  background-image:
    linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size: var(--login-grid, 24px) var(--login-grid, 24px);
}

#login-view::before,
#admin-view.active.login-view::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(to right, var(--bg-surface), transparent 12%, transparent 88%, var(--bg-surface)),
    linear-gradient(to bottom, var(--bg-surface), transparent 25%, transparent 75%, var(--bg-surface));
}

/* Dashboard */
.dashboard-view {
  background: var(--bg-surface);
}

.dashboard-header {
  padding: 20px 16px 12px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

@media (display-mode: standalone) {
  .dashboard-header {
    padding-top: 24px;
  }
}

.dashboard-header h1 {
  font-size: var(--fs-lg);
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* Session / Chat */
.session-view {
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-primary);
}

.session-header {
  display: flex;
  align-items: center;
  height: var(--header-h);
  min-height: var(--header-h);
  padding: 0 14px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  gap: 10px;
  background: var(--bg-secondary);
}

.session-header .back-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--text-secondary);
  font-size: var(--fs-sm);
  cursor: pointer;
  padding: 7px 10px;
  border-radius: var(--radius-sm);
  border: none;
  background: none;
  font-family: var(--font);
  transition: all var(--transition-fast);
  flex-shrink: 0;
  -webkit-tap-highlight-color: transparent;
}

.session-header .back-btn:hover {
  color: var(--text-primary);
  background: var(--bg-hover);
}

.session-header .project-name {
  flex: 1;
  font-weight: 600;
  font-size: var(--fs-base);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
  letter-spacing: -0.01em;
}

.chat-container {
  flex: 1;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 0;
  position: relative;
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;
  padding: 8px 0;
  position: relative;
  background-color: var(--bg-surface);
  background-image:
    linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size: 24px 24px;
  background-attachment: local;
  overflow-anchor: auto;
}

.chat-messages::after {
  content: '';
  display: block;
  overflow-anchor: auto;
  height: 1px;
}

.chat-container::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(to bottom, var(--bg-surface), transparent 40px, transparent calc(100% - 40px), var(--bg-surface));
}

.chat-input-area {
  padding: 8px 12px calc(4px + var(--safe-bottom));
  background: var(--bg-primary);
  flex-shrink: 0;
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 2;
}

@media (max-width: 600px) {
  .session-header {
    height: 48px;
    min-height: 48px;
    padding: 0 10px;
    gap: 8px;
  }

  .session-header .back-btn span {
    display: none;
  }

  .session-header .project-name {
    font-size: var(--fs-sm);
  }

  .chat-input-area {
    padding: 6px 10px calc(2px + var(--safe-bottom));
  }
}

/* ─── Tablet layout ─── */
@media (min-width: 768px) {
  #login-view,
  #admin-view.login-view {
    --login-grid: 32px;
    padding: 48px;
    padding-bottom: 12px;
  }

  #login-view::before,
  #admin-view.login-view::before {
    background:
      linear-gradient(to right, var(--bg-surface), transparent 8%, transparent 92%, var(--bg-surface)),
      linear-gradient(to bottom, var(--bg-surface), transparent 15%, transparent 85%, var(--bg-surface));
  }

  .chat-messages {
    padding: 12px 0;
  }

  .chat-container::before {
    background:
      linear-gradient(to bottom, var(--bg-surface), transparent 56px, transparent calc(100% - 56px), var(--bg-surface));
  }
}

@media (min-width: 1024px) {
  #login-view,
  #admin-view.login-view {
    --login-grid: 40px;
    padding: 56px;
  }

  #login-view::before,
  #admin-view.login-view::before {
    background:
      linear-gradient(to right, var(--bg-surface), transparent 10%, transparent 90%, var(--bg-surface)),
      linear-gradient(to bottom, var(--bg-surface), transparent 12%, transparent 88%, var(--bg-surface));
  }
}