.app {
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border-primary);
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.header-brand-link {
  display: flex;
  align-items: center;
  text-decoration: none;
  transition: opacity 0.15s;
  flex-shrink: 0;
}

.header-brand-link:hover {
  opacity: 0.8;
}

.app-logo {
  height: 32px;
  width: auto;
}

.app-title {
  font-size: 20px;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
  margin: 0;
}

.app-title-link {
  all: unset;
  cursor: pointer;
}

.app-title-link:hover {
  opacity: 0.8;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-primary);
  border-radius: 8px;
  background: var(--bg-primary);
  color: var(--text-secondary);
  transition: all 0.15s;
}

.icon-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--accent-primary);
}

.app-main {
  display: flex;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.sidebar {
  width: 300px;
  min-width: 300px;
  flex-shrink: 0;
  padding: 16px;
  overflow-y: auto;
  overflow-x: hidden;
  border-right: 1px solid var(--border-primary);
  background: var(--bg-secondary);
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-height: calc(100vh - 57px);
}

.content {
  flex: 1;
  min-height: 0;
  padding: 20px 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* ── Tablet: stack sidebar above content ──────────────────────── */
@media (max-width: 900px) {
  .app-header {
    padding: 10px 16px;
  }
  .app-main {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    min-width: auto;
    max-height: 200px;
    flex-shrink: 0;
    border-right: none;
    border-bottom: 1px solid var(--border-primary);
  }
  .content {
    padding: 16px;
  }
}

/* ── Phone ────────────────────────────────────────────────────── */
@media (max-width: 480px) {
  .app-header {
    padding: 8px 12px;
    gap: 4px;
  }
  .app-logo {
    height: 24px;
  }
  .app-title {
    font-size: 14px;
  }
  .header-left {
    gap: 6px;
  }
  .header-right {
    gap: 4px;
  }
  .icon-btn {
    width: 32px;
    height: 32px;
  }
  .sidebar {
    max-height: 160px;
    padding: 8px;
  }
  .content {
    padding: 12px;
  }
}